Analog-Devices-ADRF6801ACPZ-R7

Part #Analog-Devices-ADRF6801ACPZ-R7
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Analog-Devices-ADRF6801ACPZ-R7
750 MHz to 1150 MHz Quadrature  
Demodulator with Fractional-N PLL and VCO  
Data Sheet  
FEATURES  
GENERAL DESCRIPTION  
IQ demodulator with integrated fractional-N PLL  
LO frequency range: 750 MHz to 1150 MHz  
Input P1dB: 12.5 dBm  
Input IP3: 25 dBm  
Noise figure (DSB): 14.3 dB  
Voltage conversion gain: 5.1 dB  
Quadrature demodulation accuracy  
Phase accuracy: 0.3°  
The ADRF6801 is a high dynamic range IQ demodulator with  
integrated PLL and VCO. The fractional-N PLL/synthesizer  
generates a frequency in the range of 3.0 GHz to 4.6 GHz. A  
divide-by-4 quadrature divider divides the output frequency of  
the VCO down to the required local oscillator (LO) frequency  
to drive the mixers in quadrature. Additionally, an output buffer  
can be enabled that generates an f

VCO

/2 signal for external use.  
The PLL reference input is supported from 10 MHz to 160 MHz.  
The phase detector output controls a charge pump whose output  
is integrated in an off-chip loop filter. The loop filter output is  
then applied to an integrated VCO.  
Amplitude accuracy: 0.05 dB  
Baseband demodulation: 275 MHz, 3 dB bandwidth  
SPI serial interface for PLL programming  
40-lead, 6 mm × 6 mm LFCSP  
The IQ demodulator mixes the differential RF input with the  
complex LO derived from the quadrature divider. The differential  
I and Q output paths have excellent quadrature accuracy and  
can handle baseband signaling or complex IF up to 120 MHz.  
APPLICATIONS  
QAM/QPSK RF/IF demodulators  
Cellular W-CDMA/CDMA/CDMA2000  
Microwave point-to-(multi)point radios  
Broadband wireless and WiMAX  
The ADRF6801 is fabricated using an advanced silicon-germanium  
BiCMOS process. It is available in a 40-lead, exposed-paddle,  
RoHS-compliant, 6 mm × 6 mm LFCSP package. Performance is  
specified over the −40°C to +85°C temperature range.  
FUNCTIONAL BLOCK DIAGRAM  
GND VCCLO VCCLO
 
LOSEL  
IBBP  
33  
IBBN  
32  
GND  
31  
35  
34  
36  
17  
BUFFER  
CTRL  
30  
ADRF6801  
GND  
LON
37  
29  
28  
27  
VCCBB  
GND  
BUFFER  
BUFFER  
38  
LOP  
VCCRF  
DIVIDER  
÷1  
INTEGER  
REG  
FRACTION  
REG  
MODULUS  
MUX  
11  
GND  
DATA  
CLK  
LE  
OR  
÷2  
12  
13  
14  
15  
SPI  
QUAD  
÷2  
THIRD-ORDER  
INTERFACE  
26
RFIN  
FRACTIONAL  
INTERPOLATOR  
PRESCALER  
VCO  
CORE  
GND  
N COUNTER  
25  
24  
GNDRF  
GND  
÷2  
×2  
6
7
REFIN  
GND  
–
+
PHASE  
MUX  
÷
2  
23  
22  
21  
TEMP  
CHARGE PUMP  
250µA,  
500µA (DEFAULT),  
750µA,  
GND  
FREQUENCY  
DETECTOR  
SENSOR  
VCCBB  
GND  
÷
4  
3.3V LDO  
2.5V LDO  
9
VCO LDO  
1000µA  
8
MUXOUT  
1
2
10  
16  
3
4
5
39  
40  
18  
19  
20  
VCC1 DECL3  
VCC2  
CPOUT GND
 
RSET  
VTUNE  
DECL1  
QBBP QBBN GND  
GND  
DECL2  
Figure 1.  
Rev. A  
Information furnished by Analog Devices is believed to be accurate and reliable. However, no  
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other  
right
s
o
f third parties that may result fro
m
i
ts use. Specifications subject to change without notice. No  
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.  
Trademarks an
d
r
egistere
d
t
rademarks are the property of their respective owners.  
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.  
Tel: 781.329.4700
 
©2011–2018 Analog Devices, Inc. All rights reserved.  
 
 
 
 

Data Sheet  
TABLE OF CONTENTS  
REVISION HISTORY  
6/2018—Rev. 0 to Rev. A  
Change to Register Structure Section …………………………………… 14  
Changes to Register Programming Section ………………………….. 22  
1/2011—Revision 0: Initial Version  
Rev. A | Page 2 of 34  
 

Data Sheet  
SPECIFICATIONS  
V

S

= 5 V; ambient temperature (T

A

) = 25°C; f

REF

= 26 MHz, f

LO

= 900 MHz, f

BB

= 4.5 MHz, R

LOAD

= 450 Ω differential, all register and PLL  
settings use the recommended values shown in the

section, unless otherwise noted.  
Table 1.  
Parameter  
Test Conditions/Comments  
RFIN pins  
With VCO amplitude = 63 (R6 [DB15 to DB10])  
With VCO amplitude = 24 (R6 [DB15 to DB10])  
Measured at 900 MHz  
Min  
Typ  
Max Unit  
RF INPUT AT 900 MHz  
Internal LO Frequency Range  
750  
750  
1125 MHz  
1150 MHz  
dB  
Input Return Loss  
Input P1dB  
Second-Order Input Intercept (IIP2)  
Third-Order Input Intercept (IIP3)  
Noise Figure  
<−20  
12.5  
>65  
25  
14.3  
18.9  
−75  
dBm  
dBm  
dBm  
dB  
dB  
dBm  
−5 dBm each tone  
−5 dBm each tone  
Double sideband from RF to either I or Q output  
With a −10 dBm interferer 5 MHz away  
At 1×LO frequency, 50 Ω termination at the RF port  
IBB
P
,
I
BBN, QBB
P
,
Q
BBN pins  
450 Ω differential load across IBB
P
,
I
BBN (or QBB
P
,
Q
BBN)  
1 V p-p signal 3 dB bandwidth  
LO-to-RF Leakage  
I/Q BASEBAND OUTPUTS  
Voltage Conversion Gain  
Demodulation Bandwidth  
Quadrature Phase Error  
I/Q Amplitude Imbalance  
Output DC Offset (Differential)  
Output Common-Mode Voltage  
Gain Flatness  
5.1  
275  
0.3  
0.05  
5
V

POS

− 2.4  
0.2  
4
2.4  
12  
dB  
MHz  
Degrees  
dB  
mV  
V
dB p-p  
V p-p  
V p-p  
mA p-p  
Any 5 MHz (<100 MHz)  
Differential 450 Ω load  
Differential 200 Ω load  
Each pin  
Maximum Output Swing  
Maximum Output Current  
LO INPUT/OUTPUT  
Output Level  
LO
P
,
L
ON  
Into a differential 50 Ω load, LO buffer enabled (LO  
frequency = 900 MHz, output frequency = 1800 MHz)  
−2.5  
dBm  
Input Level  
Input Impedance  
VCO Operating Frequency  
Externally applied 2×LO, PLL disabled  
Externally applied 2×LO, PLL disabled  
With VCO amplitude = 63 (R6 [DB15 to DB10])  
With VCO amplitude = 24 (R6 [DB15 to DB10])  
0
50  
dBm  
Ω
4500 MHz  
3000  
3000  
4600 MHz  
SYNTHESIZER SPECIFICATIONS  
All synthesizer specifications measured with  
recommended settings provided in

through  
Channel Spacing  
PLL Bandwidth  
f

PFD

= 26 MHz; modulus = 2047  
Can be adjusted with off-chip loop filter component  
values and R

SET  

25  
130  
kHz  
kHz  
SPURS  
f

LO

= 900 MHz, f

REF

= 26 MHz, f

PFD

= 26 MHz, measured  
at BB outputs with f

BB

= 50 MHz  
Reference Spurs  
f

REF

= 26 MHz, f

PFD

= 26 MHz  
f

PFD

/2  
f

PFD

× 2  
f

PFD

× 3  
−91.6  
−107.8  
−89.1  
−94.2  
dBc  
dBc  
dBc  
dBc  
Rev. A | Page 3 of 34  
 

Data Sheet  
Parameter  
Test Conditions/Comments  
Min  
Typ  
Max Unit  
PHASE NOISE (USING 130 kHz LOOP FI
L
T
ER)
 
f

LO

= 900 MHz, f

REF

= 26 MHz, f

PFD

= 26 MHz, measured  
at BB outputs with f

BB

= 50 MHz  
1 kHz offset  
−99.5  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
°rms  
10 kHz offset  
100 kHz offset  
500 kHz offset  
1 MHz offset  
5 MHz offset  
10 MHz offset  
−107.8  
−106.6  
−126.7  
−131.7  
−143.5  
−150.5  
0.16  
Integrated Phase Noise  
1 kHz to 10 MHz integration bandwidth  
PHASE NOISE (USING 2.5 kHz LOOP FI
L
T
ER)  
f

LO

= 900 MHz, f

REF

= 26 MHz, f

PFD

= 26 MHz, measured  
at BB outputs with f

BB

= 50 MHz  
1 kHz offset  
10 kHz offset  
100 kHz offset  
500 kHz offset  
1 MHz offset  
5 MHz offset  
10 MHz offset  
−71.3  
−88.3  
−114.1  
−129.5  
−138.6  
−150.2  
−150.3  
−215.4  
−220.9  
26  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
dBc/Hz  
PLL FIGURE OF MERIT (FOM)  
Measured with f

REF

= 26 MHz, f

PFD

= 26 MHz  
Measured with f

REF

= 104 MHz, f

PFD

= 26 MHz  
dBc/Hz/Hz  
dBc/Hz/Hz  
MHz  
Phase Detector Frequency  
REFERENCE CHARACTERISTICS  
REFIN Input Frequency  
REFIN Input Capacitance  
MUXOUT Output Level  
20  
10  
40  
REFIN, MUXOUT pins  
Usable range  
160  
0.25  
MHz  
pF  
V
4
V

OL

(lock detect output selected)  
V

OH

(lock detect output selected)  
2.7  
V
REFOUT Duty Cycle  
CHARGE PUMP  
50  
%
Pump Current  
Output Compliance Range  
LOGIC INPUTS  
500  
µA  
V
1
2.8  
CLK, DATA, LE pins  
Input High Voltage, V

INH  

Input Low Voltage, V

INL  

Input Current, I

INH

/I

INL  

Input Capacitance, C

IN  

POWER SUPPLIES  
1.4  
0
3.3  
0.7  
V
V
µA  
pF  
0.1  
5
VCC1, VCC2, VCCLO, VCCBB, VCCRF pins  
Voltage Range (5 V)  
Supply Current (5 V)  
4.75  
5
5.25  
V
Normal Rx mode, internal LO  
Rx mode, internal LO with LO buffer enabled  
Rx mode, using external LO input (internal VCO, PLL shut  
down)  
262  
288  
157  
mA  
mA  
mA  
Supply Current (5 V)  
Power-down mode  
20  
mA  
Rev. A | Page 4 of 34  

Data Sheet  
TIMING CHARACTERISTICS  
V

S

= 5
V
,
u
nless otherwise noted.  
Table 2.  
Parameter  
Limit at T

MIN

to T

MAX

(B Version)  
Unit  
Test Conditions/Comments  
LE setup time  
DATA to CLK setup time  
DATA to CLK hold time  
CLK high duration  
CLK low duration  
t

1  

t

2  

t

3  

t

4  

t

5  

t

6  

t

7  

20  
10  
10  
25  
25  
10  
20  
ns min  
ns min  
ns min  
ns min  
ns min  
ns min  
ns min  
CLK to LE setup time  
LE pulse width  
Timing Diagram  
t

4  

t

5  

CLOCK  
t

2  

t

3  

DB1  
(CONTROL BIT C2)  
DB0 (LSB)  
(CONTROL BIT C1)  
DB23 (MSB)  
DB22  
DB2  
DATA  
LE  
t

7  

t

1  

t

6  

LE  
Figure 2. Timing Diagram  
Rev. A | Page 5 of 34  
 
 

Data Sheet  
ABSOLUTE MAXIMUM RATINGS  
Table 3.  
ESD CAUTION  
Parameter  
Rating  
Supply Voltage, VCC1, VCC2, VCCLO,  
VCCBB, and VCCRF (V

S1

)  
−0.5 V to +5.5 V  
Digital I/O, CLK, DATA, and LE  
RFIN  
−0.3 V to +3.6 V  
16 dBm  
θ

JA

(Exposed Paddle Soldered Down)  
Maximum Junction Temperature  
Operating Temperature Range  
Storage Temperature Range  
30°C/W  
150°C  
−40°C to +85°C  
−65°C to +150°C  
Stresses at or above those listed under Absolute Maximum  
Ratings may cause permanent damage to the product. This is a  
stress rating only; functional operation of the product at these  
or any other conditions above those indicated in the operational  
section of this specification is not implied. Operation beyond  
the maximum operating conditions for extended periods may  
affect product reliability.  
Rev. A | Page 6 of 34  
 

Data Sheet  
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS  
VCO  
LDO  
BUFFER  
CTRL  
30 GND  
VCC1  
DECL3  
CPOUT  
GND  
1
2
29 VCCBB  
28 GND  
SCALE  
BLEED  
PHASE DETECTOR  
AND  
3
CHARGE PUMP  
27 VCCRF  
26 RFIN  
4
5
6
7
8
9
DIV  
CTRL  
RSET  
DIV  
÷1  
OR  
÷2  
VCO  
BAND  
VCO  
3000MHz  
TO  
QUADRATURE  
÷2  
6
6
MUX  
×
2  
CURRENT  
CAL/SET  
25 GNDRF  
24 GND  
REFIN  
GND  
4600MHz  
MUX  
÷2  
÷4  
PROGRAMABLE  
DIVIDER  
PRESCALER  
÷2  
ENABLE  
23 GND  
MUXOUT  
DECL2  
22 VCCBB  
21 GND  
2.5V  
LDO  
THIRD-ORDER  
SDM  
VCC2 10  
MODULUS  
FRACTION  
INTEGER  
SERIAL PORT  
Figure 3. Pin Configuration  
Table 4. Pin Function Descriptions  
Pin No.  
Mnemonic  
Description  
The 5 V Power Supply Pin for VCO and PLL (VCC1).  
Decoupling Node for the 3.3 V LDO. Connect a 0.1 µF capacitor between this pin and ground.  
Charge Pump Output Pin. Connect this pin to VTUNE through the loop filter.  
Connect these pins to a low impedance ground plane.  
1
2
3
VCC1  
DECL3  
CPOUT  
GND  
4, 7, 11, 15, 16, 20, 21,  
23, 24, 28, 30, 31, 35  
Rev. A | Page 7 of 34  
 
 

Data Sheet  
Pin No.  
Mnemonic  
Description  
5
RSET  
Charge Pump Current. The nominal charge pump current can be set to 250 µA, 500 µA, 750 µA, or 1  
mA using DB10 and DB11 of Register 4 and by setting DB18 to 0 (internal reference current). In this  
mode, no external R

SET

is required. If DB18 is set to 1, the four nominal charge pump currents  
(I

NOMINAL

) can be externally tweaked according to the following equation where the resulting value is in  
units of ohms.  
217.
4
×
I

CP  

I

NOMINAL  

R

SET  

=
−
37.8  
6
8
REFIN  
MUXOUT  
Reference Input. Nominal input level is 1 V p-p. Input range is 10 MHz to 160 MHz.  
Multiplexer Output. This output can be programmed to provide the reference output signal or  
the lock detect signal. The output is selected by programming the appropriate register.  
9
DECL2  
VCC2  
DATA  
CLK  
Decoupling Node for 2.5 V LDO. Connect a 0.1 µF capacitor between this pin and ground.  
The 5 V power supply pin for the 2.5 V LDO.  
Serial Data Input. The serial data is loaded MSB first with the three LSBs being the control bits.  
Serial Clock Input. This serial clock is used to clock in the serial data to the registers. The data is  
latched into the 24-bit shift register on the CLK rising edge. Maximum clock frequency is 20 MHz.  
10  
12  
13  
14  
LE  
Load Enable. When the LE input pin goes high, the data stored in the shift registers is loaded into  
one of the six registers, the relevant latch being selected by the first three control bits of the 24-bit  
word.  
17, 34  
18, 19  
22, 29  
25  
VCCLO  
QBB
P
,
Q
BBN  
VCCBB  
GNDRF  
RFIN  
The 5 V Power Supply for the LO Path Blocks.  
Demodulator Q-Channel Differential Baseband Outputs; Differential Output Impedance of 24 Ω.  
The 5 V Power Supply for the Baseband Output Section of the Demodulator Blocks.  
Ground Return for RF Input Balun.  
26  
Single-Ended, Ground Referenced 50 Ω, RF Input.  
27  
32, 33  
36  
VCCRF  
IBBN, IBBP  
LOSEL  
The 5 V Power Supply for the RF Input Section of the Demodulator Blocks.  
Demodulator I-Channel Differential Baseband Outputs; Differential Output Impedance of 24 Ω.  
LO Select. Connect this pin to ground for the simplest operation and to completely control the LO  
path and input/output direction from the register SPI programming.  
For additional control without register reprogramming, this input pin can determine whether the  
LOP and LON pins operate as inputs or outputs. LOP and LON become inputs if the LOSEL pin is  
set low, the LDRV bit of Register 5 is set low, and the LXL bit of Register 5 is set high. The  
externally applied LO drive must be at 2×LO frequency (and the LDIV bit of Register 5 (DB5) set  
low). LON and LOP become outputs when LOSEL is high or if the LDRV bit of Register 5 (DB3) is set  
high and the LXL bit of Register 5 (DB4) is set low. The output frequency is 2×LO frequency (and  
the LDIV bit of Register 5 (DB5) must be set high). This pin should not be left floating.  
37, 38  
LON, LOP  
Local Oscillator Input/Output. When these pins are used as output pins, a differential frequency  
divided version of the internal VCO is available on these pins. When the internal LO generation is  
disabled, an external M×LO frequency signal can be applied to these pins (where M corresponds  
to the LO path divider setting). (Differential Input/Output Impedance of 50 Ω)  
39  
40  
VTUNE  
DECL1  
EP  
VCO Control Voltage Input. This pin is driven by the output of the loop filter. The nominal input  
voltage range on this pin is 1.0 V to 2.8 V.  
Connect a 10 µF capacitor between this pin and ground as close to the device as possible  
because this pin serves as the VCO supply and loop filter reference.  
Exposed Paddle. The exposed paddle should be soldered to a low impedance ground plane.  
Rev. A | Page 8 of 34  

Data Sheet  
TYPICAL PERFORMANCE CHARACTERISTICS  
V

S

= 5
V
,
T

A

= 25°C, unless otherwise noted. LO = 750 MHz to 1150 MHz.  
16  
80  
75  
70  
65  
60  
55  
50  
14  
IP1dB  
12  
T
T
T
= +85°C  
= +25°C  
= –40°C  
A
A
A
10  
8
T
T
T
= +85°C  
= +25°C  
= –40°C  
A
A
A
GAIN  
6
I CHANNEL  
Q CHANNEL  
4
2
0
750  
750  
800  
850  
900  
950  
1000 1050  
1100  
1150  
800  
850  
900  
950  
1000  
1050  
1100  
1150  
LO FREQUENCY (MHz)  
LO FREQUENCY (MHz)  
Figure 4. Conversion Gain and Input P1dB vs. LO Frequency  
Figure 7. Input IP2 vs. LO Frequency  
35  
20  
33  
31  
29  
27  
25  
23  
21  
19  
17  
15  
19  
18  
17  
16  
15  
14  
13  
12  
11  
10  
T
T
T
= +85°C  
= +25°C  
= –40°C  
A
A
A
T
T
T
= +85°C  
= +25°C  
= –40°C  
A
A
A
750  
800  
850  
900  
950  
1000  
1050 1100  
1150  
750  
800  
850  
900  
950  
1000  
1050  
1100  
1150  
LO FREQUENCY (MHz)  
LO FREQUENCY (MHz)  
Figure 5. Input IP3 vs. LO Frequency  
Figure 8. Noise Figure vs. LO Frequency  
5
1.0  
0.8  
4
3
T
T
T
= +85°C  
= +25°C  
= –40°C  
A
A
A
0.6  
T
T
T
= +85°C  
= +25°C  
= –40°C  
A
A
A
2
0.4  
1
0.2  
0
0
–1  
–2  
–3  
–4  
–5  
–0.2  
–0.4  
–0.6  
–0.8  
–1.0  
750  
800  
850  
900  
950  
1000  
1050  
1100  
1150  
750  
800  
850  
900  
950  
1000  
1050  
1100  
1150  
LO FREQUENCY (MHz)  
LO FREQUENCY (MHz)  
Figure 6. IQ Gain Mismatch vs. LO Frequency  
Figure 9. IQ Quadrature Phase Error vs. LO Frequency  
Rev. A | Page 9 of 34  
 

Data Sheet  
1
0
–50  
–55  
–60  
–65  
–70  
–75  
–80  
–85  
–90  
–1  
–2  
–3  
–4  
–5  
–6  
–7  
1
10  
100  
750  
800  
850  
900  
950  
1000  
1050  
1100  
1150  
LO FREQUENCY (MHz)  
BASEBAND FREQUEN
C
Y
 
(MHz)  
Figure 10. LO-to-RF Feedthrough vs. LO Frequency, LO Output Turned Off  
Figure 13. Normalized Baseband Frequency Response vs. Baseband  
Frequency  
–
35  
80  
IIP2  
–40  
–45  
–50  
–55  
–60  
–65  
–70  
–75  
70  
60  
T
T
T
= +85°C  
= +25°C  
= –40°C  
A
A
A
50  
40  
30  
20  
10  
0
I CHANNEL  
Q CHANNEL  
IIP3  
IP1dB  
750  
800  
850  
900  
950  
1000  
1050  
1100 1150  
5
10  
15  
20  
25  
30  
35  
40  
45  
50  
LO FREQUENCY (MHz)  
BASEBAND FREQUEN
C
Y (MHz)  
Figure 11. LO-to-BB Feedthrough vs. LO Frequency, LO Output Turned Off  
Figure 14. Input P1dB, Input IP2, and Input IP3 vs. Baseband Frequency  
–
30  
34  
32  
30  
28  
26  
24  
22  
20  
18  
16  
14  
12  
10  
–35  
–40  
–45  
–50  
–55  
–60  
–65  
–70  
750  
800  
850  
900  
950  
1000  
1050  
1100  
1150  
–35  
–30  
–25  
–20  
–15  
–10  
–5  
0
5
RF FREQUENCY (MHz)  
INPUT BLOCKER POWER (dBm)  
Figure 12. RF-to-BB Feedthrough vs. RF Frequency  
Figure 15. Noise Figure vs. Input Blocker Level,  

LO

= 900 MHz (RF Blocker 5 MHz Offset)  
f
Rev. A | Page 10 of 34  

Data Sheet  
0
2.0  
1.9  
1.8  
1.7  
1.6  
1.5  
1.4  
1.3  
1.2  
–5  
–10  
–15  
–20  
–25  
–30  
–35  
–40  
750  
800  
850  
900  
950  
1000  
1050  
1100  
1150  
–40  
–15  
10  
35  
60  
85  
RF FREQUENCY (MHz)  
TEMPERATURE (°C)  
Figure 16. RF Input Return Loss vs. RF Frequency  
Figure 19. VPTAT vs. Temperature  
0
–2  
3.5  
3.0  
2.5  
2.0  
1.5  
1.0  
0.5  
T
T
T
= +85°C  
= +25°C  
= –40°C  
A
A
A
–4  
–6  
–8  
–10  
12  
–14  
–16  
1500  
1600  
1700  
1800 1900  
2000  
2100  
2200  
2300  
750  
800  
850  
900  
950  
1000 1050  
1100  
1150  
LO
P
,
L
ON OUTPUT FREQUENCY (MHz)  
LO FREQUENCY (MHz)  
Figure 17. LO Output Return Loss vs. LO Output Frequency, LO Output  
Enabled (1500 MHz to 2300 MHz), Measured through TC1-1-13 Balun  
Figure 20. VTUNE vs. LO Frequency  
400  
380  
360  
T
T
T
= +85°C  
= +25°C  
= –40°C  
A
A
A
340  
320  
300  
280  
260  
240  
220  
200  
750  
800  
850  
900  
950  
1000  
1050  
1100  
1150  
LO FREQUENCY (MHz)  
Figure 18. 5 V Supply Currents vs. LO Frequency,  
LO Output Enabled  
Rev. A | Page 11 of 34  

Data Sheet  
SYNTHESIZER/PLL  
V

S

= 5
V
.
S
ee the

section for recommended settings used. External loop filter bandwidths of ~130 kHz and 2.5 kHz  
used (see plots within this section for annotations), f

REF

= f

PFD

= 26 MHz, measured at BB output, f

BB

= 50 MHz, unless otherwise noted.  
–
40  
1.0  
0.9  
0.8  
0.7  
0.6  
0.5  
0.4  
0.3  
0.2  
0.1  
0
T
T
T
= +85°C  
= +25°C  
= –40°C  
A
A
A
T
T
T
= +85°C  
= +25°C  
= –40°C  
A
A
A
–60  
–80  
130kHz LOOP FILTER  
BANDWIDTH  
–100  
–120  
–140  
–160  
2.5kHz LOOP FILTER  
BANDWIDTH  
750  
800  
850  
900  
950  
1000  
1050  
1100  
1150  
1k  
10k  
100k  
1M  
10M  
OFFSET FREQUENCY (Hz)  
LO FREQUENCY (MHz)  
Figure 21. Phase Noise vs. Offset Frequency, f

LO

= 900 MHz, Shown for Loop  
Filter Bandwidths of 2.5 kHz and 130 kHz  
Figure 24. Integrated Phase Noise vs. LO Frequency (Spurs Omitted), Using  
Loop Filter Bandwidth of 130 kHz  
–70  
–50  
T
T
T
= +85°C  
= +25°C  
= –40°C  
A
A
A
1 × PFD FREQUENCY  
3 × PFD FREQUENCY  
0.5 × PFD FREQUENCY  
1kHz  
OFFSET  
–75  
–80  
–70  
10kHz  
OFFSET  
–90  
1kHz OFFSET  
–85  
–90  
–110  
130kHz LOOP FILTER BANDWIDTH  
2.5kHz LOOP FILTER BANDWIDTH  
10kHz  
OFFSET  
–95  
T
T
T
= +85°C  
= +25°C  
= –40°C  
A
A
A
–130  
5MHz  
OFFSET  
–100  
–105  
–110  
–150  
–170  
5MHz  
OFFSET  
750  
800  
850  
900  
950  
1000  
1050  
1100  
1150  
750  
800  
850  
900  
950  
1000  
1050  
1100  
1150  
LO FREQUENCY (MHz)  
LO FREQUENCY (MHz)  
Figure 22. PLL Reference Spurs vs. LO Frequency, Using Loop Filter  
Bandwidth of 130 kHz  
Figure 25. Phase Noise vs. LO Frequency (1 kHz, 10 kHz, and 5 MHz Offsets),  
Shown for Loop Filter Bandwidths of 2.5 kHz and 130 kHz  
–
90  
–70  
T
T
T
= +85°C  
= +25°C  
= –40°C  
A
A
A
2 × PFD FREQUENCY  
4 × PFD FREQUENCY  
–75  
–80  
–100  
–110  
–120  
–130  
–140  
–150  
–160  
100kHz OFFSET  
–85  
100kHz OFFSET  
1MHz OFFSET  
–90  
–95  
–100  
–105  
–110  
1MHz OFFSET  
T
T
T
= +85°C  
= +25°C  
= –40°C  
A
A
A
130kHz LOOP FILTER BANDWIDTH  
2.5kHz LOOP FILTER BANDWIDTH  
750  
800  
850  
900  
950  
1000  
1050 1100  
1150  
750  
800  
850  
900  
950  
1000  
1050  
1100  
1150  
LO FREQUENCY (MHz)  
LO FREQUENCY (MHz)  
Figure 26. Phase Noise vs. LO Frequency (100 kHz and 1 MHz Offsets), Shown  
for Loop Filter Bandwidths of 2.5 kHz and 130 kHz  
Figure 23. PLL Reference Spurs vs. LO Frequency, Using Loop Filter  
Bandwidth of 130 kHz  
Rev. A | Page 12 of 34  
 

Data Sheet  
COMPLEMENTARY CUMULATIVE DISTRIBUTION FUNCTIONS (CCDF)  
V

S

= 5
V
,
f

LO

= 900 MHz, f

BB

= 4.5 MHz.  
100  
90  
80  
70  
60  
50  
40  
30  
20  
10  
0
100  
90  
80  
70  
60  
50  
40  
30  
20  
10  
0
T
T
T
= +85°C  
= +25°C  
= –40°C  
GAIN  
A
A
A
T
T
T
= +85°C  
= +25°C  
= –40°C  
A
A
A
I CHANNEL  
Q CHANNEL  
IP1dB  
60  
62  
64  
66  
68  
70  
72  
74  
18  
2
76  
20  
3
78  
22  
4
80  
24  
5
0
2
4
6
8
10  
12  
14  
16  
18  
GAIN (dB) AND INPUT P1dB (dBm)  
INPUT IP2 (dBm)  
Figure 27. Gain and Input P1dB  
Figure 30. Input IP2  
100  
90  
80  
70  
60  
50  
40  
30  
20  
10  
0
100  
90  
80  
70  
60  
50  
40  
30  
20  
10  
0
T
T
T
= +85°C  
= +25°C  
= –40°C  
A
A
A
I CHANNEL  
Q CHANNEL  
T
T
T
= +85°C  
A
= +25°C  
= –40°C  
A
A
15  
17  
19  
21  
23  
25  
27  
29  
31  
33  
35  
4
6
8
10  
12  
14  
16  
INPUT IP3 (dBm)  
NOISE FIGURE (dB)  
Figure 28. Input IP3  
Figure 31. Noise Figure  
100  
90  
80  
70  
60  
50  
40  
30  
20  
10  
0
10
0
 
90  
80  
70  
60  
50  
40  
30  
20  
10  
0
T
T
T
= +85°C  
= +25°C  
= –40°C  
A
A
A
T
T
T
= +85°C  
= +25°C  
= –40°C  
A
A
A
–0.5 –0.4 –0.3 –0.2 –0.1  
0
0.1  
0.2  
0.3  
0.4  
0.5  
–5  
–4  
–3  
–2  
–1  
0
1
IQ GAIN MISMATCH (dB)  
IQ QUADRATURE PHASE ERROR (Degrees)  
Figure 29. IQ Gain Mismatch  
Figure 32. IQ Quadrature Phase Error  
Rev. A | Page 13 of 34  
 

Data Sheet  
CIRCUIT DESCRIPTION  
The ADRF6801 integrates a high performance IQ demodulator  
with a state-of-the-art fractional-N PLL. The PLL also integrates  
a low noise VCO. The SPI port allows the user to control the  
fractional-N PLL functions, the demodulator LO divider functions,  
and optimization functions, as well as allowing for an externally  
applied LO.  
BIAS CIRCUITRY  
There are several band gap reference circuits and three low  
dropout regulators (LDOs) in the ADRF6801 that generate the  
reference currents and voltages used by different sections. The  
first of the LDOs is the 2.5 V LDO, which is always active and  
provides the 2.5 V supply rail used by the internal digital logic  
blocks. The 2.5 V LDO output is connected to DECL2 (Pin 9)  
for the user to provide external decoupling.  
The ADRF6801 uses a high performance mixer core that results  
in an exceptional input IP3 and input P1dB, with a very low output  
noise floor for excellent dynamic range.  
The second LDO is the VCO LDO, which acts as the positive  
supply rail for the internal VCO. The VCO LDO output is  
connected to DECL2 (Pin 40) for the user to provide external  
decoupling. The VCO LDO can be powered down by setting  
Register 6, DB18 = 0, which allows the user to save power when  
not using the VCO.  
LO QUADRATURE DRIVE  
A signal at 2× the desired mixer LO frequency is delivered to  
a divide-by-2 quadrature phase splitter followed by limiting  
amplifiers which then drive the I and Q mixers, respectively.  
V-TO-I CONVERTER  
The third LDO is the 3.3 V LDO, which acts as the 3.3 V  
positive supply rail for the reference input, phase frequency  
detector, and charge pump circuitry. The 3.3 V LDO output is  
connected to DECL3 (Pin 2) for the user to provide external  
decoupling. The 3.3 V LDO can be powered down by setting  
Register 6, DB19 = 0, which allows the user to save power when  
not using the VCO. The demodulator also has a bias circuit that  
supplies bias current for the mixer V-to-I stage, which then sets  
the bias for the mixer core. The demodulator bias cell can also  
be shut down by setting Register 5, DB7 = 0.  
The RF input signal is applied to an on-chip balun which then  
provides both a ground referenced, 50 Ω single-ended input  
impedance and a differential voltage output to a V-to-I converter  
that converts the differential voltages to differential output currents.  
These currents are then applied to the emitters of the Gilbert  
cell mixers.  
MIXERS  
The ADRF6801 has two double-balanced mixers: one for the  
in-phase channel (I channel) and one for the quadrature channel  
(Q channel). These mixers are based on the Gilbert cell design  
of four cross-connected transistors. The output currents from  
the two mixers are summed together in the resistive loads that  
then feed into the subsequent emitter follower buffers.  
REGISTER STRUCTURE  
The ADRF6801 provides access to its many programmable  
features through a 3-wire SPI control interface that is used to  
program the seven internal registers. The minimum delay and  
hold times are shown in the timing diagram (see

. The  
SPI provides digital control of the internal PLL/VCO as well as  
several other features related to the demodulator core, on-chip  
referencing, and available system monitoring functions. The  
MUXOUT pin provides a convenient, single-pin monitor output  
signal that can be used to deliver a PLL lock-detect signal or an  
internal voltage proportional to the local junction temperature.  
EMITTER FOLLOWER BUFFERS  
The output emitter followers drive the differential
 
I and Q signals  
off chip. The output impedance is set by on-chip 12 Ω series  
resistors that yield a 24 Ω differential output impedance for each  
baseband port. The fixed output impedance forms a voltage divider  
with the load impedance that reduces the effective gain. For example,  
a 500 Ω differential load has ~0.5 dB lower effective gain than  
with a high (10 kΩ) differential load impedance.  
Note that internal calibration for the PLL must run when the  
ADRF6801 is initialized at a given frequency. This calibration is run  
automatically whenever Register 0, Register 1, or Register 2 is  
programmed. Because the other registers affect PLL performance,  
Register 0, Register 1, and Register 2 must always be programmed  
last. For ease of use, starting the initial programming with  
Register 6 and then programming the registers in descending  
order, ending with Register 0, is recommended. Once the PLL  
and other settings are programmed, the user can change the  
PLL frequency simply by programming Register 0, Register 1,  
or Register 2 as necessary.  
The common-mode dc output levels of the emitter followers are set  
from VCCBB via the voltage drop across the mixer load resistors,  
the V

BE

of the output emitter follower, and the voltage drop  
across the 12 Ω series resistor.  
Rev. A | Page 14 of 34  
 
 
 
 
 
 
 

Data Sheet  
DIVIDE  
MODE  
INTEGER DIVIDE RATIO  
CONTROL BITS  
DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10
 
DB9 DB8
 
DB7 DB6 DB5
 
DB4 DB3 DB2  
DB1  
DB0  
0
0
0
0
0
0
0
0
0
0
0
0
0
DM  
ID6 ID5  
ID4 ID3  
ID2  
ID1  
ID0 C3(0) C2(0) C1(0)  
DM  
DIVIDE MODE  
0
1
FRACTIONAL (DEFAULT)  
INTEGER  
DIVIDE RATIO  
ID6  
0
ID5  
0
ID4  
1
ID3  
0
ID2  
1
ID1  
0
ID0  
21 (INTEGER MODE ONLY)  
1
0
22 (INTEGER MODE ONLY)  
0
0
1
0
1
1
23 (INTEGER MODE ONLY)  
0
0
1
0
1
1
1
24  
0
0
1
1
0
0
0
…  
…  
…  
0
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
0
…  
…  
0
…  
…  
0
…  
56 (DEFAULT)  
…  
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
0
…  
…  
1
…  
…  
1
…  
…  
1
…  
119  
120 (INTEGER MODE ONLY)  
121 (INTEGER MODE ONLY)  
122 (INTEGER MODE ONLY)  
123 (INTEGER MODE ONLY)  
1
1
1
1
0
0
0
1
1
1
1
0
0
1
1
1
1
1
0
1
0
1
1
1
1
0
1
1
Figure 33. Integer Divide Control Register (R0)  
Register 0—Integer Divide Control  
The integer divide ratio sets the INT value in Equation 1. The  
IN
T
,
F
RAC, and MOD values make it possible to generate output  
frequencies that are spaced by fractions of the PFD frequency.  
With R0[2:0] set to 000, the on-chip integer divide control register  
is programmed as shown

ternal VCO  
frequency (f

VCO

) equation is  
Note that the demodulator LO frequency is given by f

LO

= f

VCO

/4.  
f

VCO

=
f

PFD

× (
INT
+ (
FRAC
/
MOD
)) × 2  
where:  

VCO

is the output frequency of the internal VCO.  
(1)  
Divide Mode  
Divide mode determines whether fractional mode or integer mode  
is used. In integer mode, the VCO output frequency, f

VCO

, is  
calculated by  
f
INT
is the preset integer divide ratio value (21 to 123 for integer  
mode, 24 to 119 for fractional mode).  
MOD
is the preset fractional modulus (1 to 2047).  
FRAC
is the preset fractional divider ratio value (0 to MOD − 1).  
f

VCO

=
f

PFD

× (
INT
) × 2  
(2)  
Rev. A | Page 15 of 34  
 

Data Sheet  
Register 1—Modulus Divide Control  
With R1[2:0] set to 001, the on-chip modulus divide control register is programmed as show

The MOD value is the preset  
fractional modulus ranging from 1 to 2047.  
MODULUS DIVIDE RATIO  
CONTROL BITS  
DB2 DB1 DB0  
MD0 C3(0)
 
C2(0) C1(1)  
DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14
 
DB13 DB12
 
DB11 DB10
 
DB9  
MD10 MD9 MD8 MD7 MD6  
DB8  
MD5  
DB7  
MD4  
DB6  
DB5  
DB4  
DB3  
0
0
0
0
0
0
0
0
0
0
MD3 MD2 MD1  
MD10 MD9 MD8 MD7 MD6 MD5 MD4 MD3 MD2 MD1 MD0  
MODULUS VALUE  
1
0
0
0
0
0
0
0
0
0
0
1
2
0
0
0
0
0
0
0
0
0
1
0
…  
…  
…  
1
…  
…  
1
…  
…  
0
…  
…  
0
…  
…  
0
…  
…  
0
…  
…  
0
…  
…  
0
…  
…  
0
…  
…  
0
…  
…  
0
…  
1536 (DEFAULT)  
…  
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
2047  
Figure 34. Modulus Divide Control Register (R1)  
Register 2—Fractional Divide Control  
With R2[2:0] set to 010, the on-chip fractional divide control register is programmed as show

The FRAC value is the preset  
fractional modulus ranging from 0 to MOD − 1.  
CONTROL BITS  
FRACTIONAL DIVIDE RATIO  
DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10
 
DB9  
DB8  
FD5  
DB7  
FD4  
DB6  
FD3  
DB5  
FD2  
DB4  
FD1  
DB3  
FD0  
DB2  
DB1  
DB0  
0
0
0
0
0
0
0
0
0
0
FD10 FD9  
FD8  
FD7  
FD6  
C3(0) C2(1) C1(0)  
FD10  
0
FD9  
0
FD8  
FD7  
FD6  
FD5  
FD4  
FD3  
FD2  
FD1  
FD0  
FRACTIONAL VALUE  
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
1
…  
…  
…  
0
…  
…  
1
…  
…  
1
…  
…  
0
…  
…  
0
…  
…  
0
…  
…  
0
…  
…  
0
…  
…  
0
…  
…  
0
…  
…  
0
…  
768 (DEFAULT)  
…  
…  
…  
…  
…  
…  
…  
…  
…  
…  
…  
…  
…  
…  
…  
…  
…  
…  
…  
…  
…  
…  
…  
…  
FRACTIONAL VALUE MUST BE LESS THAN MODULUS  
<MOD  
Figure 35. Fractional Divide Control Register (R2)  
Register 3—Σ-Δ Modulator Dither Control  
With R3[2:0] set to 011, the on-chip Σ-Δ modulator dither control register is programmed as show

ther restart value  
can be programmed from 0 to 217 to 1, though a value of 1 is typically recommended.  
DITHER  
MAGNITUDE  
DITHER  
ENABLE  
DITHER RESTART VALUE  
CONTROL BITS  
DB23 DB22  
DITH1  
DB21  
DITH0  
DB20  
DEN  
DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10
 
DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0  
DV16 DV15 DV14 DV13 DV12 DV11 DV10
 
DV9 DV8 DV7 DV6 DV5 DV4 DV3 DV2 DV1 DV0
 
C3(0) C2(1) C1(1)  
0
DEN DITHER
 
ENABLE  
0
1
DISABLE  
ENABLE (DEFAULT, RECOMMENDED)  
DITH1  
DITH0 DITHER
 
MAGNITUDE  
0
0
0
1
15 (DEFAULT)  
7
1
1
0
1
3
1 (RECOMMENDED)  
DITHER RESTART  
VALUE  
DV16 DV15 DV14 DV13 DV12 DV11 DV10
 
DV9 DV8 DV7 DV6 DV5 DV4 DV3 DV2 DV1 DV0  
0x00001 (DEFAULT)  
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
1
…  
…  
0x1FFFF  
Figure 36. Σ-Δ Modulator Dither Control Register (R3)  
Rev. A | Page 16 of 34  
 
 
 

Data Sheet  
and the divided-down VCO signal. This phase offset is used to  
linearize the PFD-CP transfer function and can improve  
fractional spurs. The magnitude of the phase offset is  
determined by  
Register 4—Charge Pump, PFD, and Reference Path  
Control  
With R4[2:0] set to 100, the on-chip charge pump, PFD, and  
reference path control register is programmed as shown in  
θ

PFD
,
OFS  

ΔΦ[deg
]
=
22.5  
I

C
P
,
MULT  

The charge pump current is controlled by the base charge  
pump current (I

C
P
,
B
ASE

) and the value of the charge pump  
current multiplier (I

C
P
,
M
ULT

).  
Finally, the phase offset can be either positive or negative  
depending on the value of the DB17 bit in Register 4.  
The base charge pump current can be set using an internal or  
external resistor (according to Bit DB18 of Register 4). When  
using an external resistor, the value of I

C
P
,
B
ASE
 

can be varied  
according to  
The reference frequency applied to the PFD can be manipulated  
using the internal reference path source. The external reference  
frequency applied can be internally scaled in frequency by 2×,  
1×, 0.5×, or 0.25×. This allows a broader range of reference  
frequency selections while keeping the reference frequency  
applied to the PFD within an acceptable range.  
217.
4
×
I  

C
P
,
BASE

  
R

SET  

[
Ω
]
=
−
37.8  
250  
The ADRF6801 also provides a MUXOUT pin that can be  
programmed to output a selection of several internal signals. The  
default mode provides a lock-detect output that allows users to  
verify when the PLL has locked to the target frequency. In addition,  
several other internal signals can be routed to the MUXOUT pin as  
described in

The actual charge pump current can be programmed to be a  
multiple (1, 2, 3, or 4) of the charge pump base current. The  
multiplying value (I

C
P
,
M
ULT

) is equal to 1 plus the value of the  
DB11 and DB10 bits in Register 4.  
The PFD phase offset multiplier (θ

PFD, OFS

), which is set by Bit  
DB16 to Bit DB12 of Register 4, causes the PLL to lock with a  
nominally fixed phase offset between the PFD reference signal  
Rev. A | Page 17 of 34  
 

Data Sheet  
PDF  
CHARGE  
PUMP  
CURRENT  
MULTIPLIER  
INPUT REF  
PATH  
SOURCE  
CHARGE  
PUMP  
REF  
CP  
CNTL  
SRC  
CHARGE  
PUMP  
CONTROL  
PFD ANTI-  
BACKLASH  
DELAY  
PHASE  
OUPUT MUX  
SOURCE  
PFD PHASE OFFSET  
MULTIPLIER VALUE  
PFD EDGE  
SENSITIVITY  
CONTROL BITS  
OFFSET  
POLARITY  
DB23  
DB22  
DB21 DB20
 
DB19  
DB18  
CPM  
DB17  
DB16 DB15
 
DB14 DB13 DB12 DB11 DB10
 
DB9  
DB8  
DB7  
DB6  
PE1  
DB5  
PE0  
DB4  
DB3  
DB2  
DB1  
DB0  
RMS2 RMS1  
RMS0  
RS1  
RS0  
CPBD  
CPB4 CPB3
 
CPB2 CPB1 CPB0
 
CPP1 CPP0
 
CPS CPC1 CPC0  
PAB1 PAB0
 
C3(1)  
C2(0)  
C1(0)  
PFD ANTIBACKLASH  
DELAY  
PAB1 PAB0  
0
0
0ns (DEFAULT,  
RECOMMENDED)  
0.5ns  
0.75ns  
0.9ns  
0
1
1
1
0
1
REFERENCE PATH EDGE  
SENSITIVITY  
PE0  
0
1
FALLING EDGE (RECOMMENDED)  
RISING EDGE (DEFAULT)  
DIVIDER PATH EDGE  
SENSITIVITY  
PE1  
0
1
FALLING EDGE (RECOMMENDED)  
RISING EDGE (DEFAULT)  
CHARGE PUMP  
CONTROL  
CPC1 CPC0  
BOTH ON  
PUMP DOWN  
PUMP UP  
0
0
1
1
0
1
0
1
TRISTATE (DEFAULT)  
CPS CHARGE
 
PUMP CONTROL SOURCE  
0
1
CONTROL BASED ON STATE OF DB7/DB8 (CP CONTROL)  
CONTROL FROM PFD (DEFAULT)  
CHARGE PUMP  
CURRENT MULTIPLIER  
CPP1 CPP0  
1
0
0
1
1
0
1
0
1
2 (DEFAULT, RECOMMENDED)  
3
4
PFD PHASE OFFSET MULTIPLIER  
CPB4 CPB3 CPB2 CPB1 CPB0  
0 × 22.5°/I  
CP, MULT  
0
0
0
0
0
1 × 22.5°/I  
…  
0
…  
0
…  
0
…  
0
…  
1
…  
CP, MULT  
6 × 22.5°/I  
…  
10 × 22.5°/I  
…  
(RECOMMENDED)  
(DEFAULT)  
0
…  
0
…  
1
0
…  
1
…  
1
1
…  
0
…  
1
1
…  
1
…  
1
0
…  
0
…  
1
CP, MULT  
CP, MULT  
31 × 22.5°/I  
CP, MULT  
CPBD PFD
 
PHASE OFFSET POLARITY  
0
1
NEGATIVE  
POSITIVE (DEFAULT, RECOMMENDED)  
CHARGE PUMP CURRENT  
REFERENCE SOURCE  
CPM  
INTERNAL (DEFAULT)  
EXTERNAL  
0
1
INPUT REFERENCE  
PATH SOURCE  
RS1 RS0  
2 × REFERENCE INPUT  
0
0
1
1
0
1
0
1
REFERENCE INPUT (DEFAULT)  
0.5 × REFERENCE INPUT  
0.25 × REFERENCE INPUT  
RMS2 RMS1 RMS0 OUTPUT
 
MUX SOURCE  
LOCK DETECT (DEFAULT)  
VPTAT  
BUFFERED VERSION OF REFERENCE INPUT  
BUFFERED VERSION OF 0.5 × REFERENCE INPUT  
BUFFERED VERSION OF 2 × REFERENCE INPUT  
TRISTATE  
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
BUFFERED VERSION OF 0.25 × F  
RESERVED (DO NOT USE)  
REF  
Figure 37. Charge Pump, PFD, and Reference Path Control Register (R4)  
Rev. A | Page 18 of 34  
 

Data Sheet  
Register 5—LO Path and Demodulator Control  
Register 5 controls whether the LOIP and LOIN pins act as an input or output, whether the divider before the polyphase divider is in  
divide-by-1 or divide-by-2, and whether the demodulator bias circuitry is enabled as detailed

LO  
DEMOD  
BIAS  
ENABLE  
LO  
LO  
IN/OUT  
CTRL  
OUTPUT  
DRIVER  
ENABLE  
FIRST  
CONTROL BITS  
DIVIDER  
DB23 DB22 DB21 DB20 DB19 DB18 DB17 DB16 DB15 DB14 DB13 DB12 DB11 DB10 DB9
 
DB8 DB7  
DB6  
0
DB5  
DB4  
LXL  
DB3 DB2
 
DB1 DB0  
LDRV C3(1)
 
C2(0) C1(1)  
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
DMBE  
LDIV  
LO OUTPUT DRIVER  
ENABLE  
LDRV  
DRIVER OFF (DEFAULT)  
DRIVER ON  
0
1
LXL LO
 
IN/OUT CONTROL  
LO OUTPUT (DEFAULT)  
LO INPUT  
0
1
LDIV  
DIVIDE RATIO  
÷ 1  
0
1
÷ 2 (DEFAULT,  
NECESSARY FOR VCO USE)  
DMBE DEMOD
 
BIAS ENABLE  
DISABLE  
ENABLE (DEFAULT)  
0
1
Figure 38. LO Path and Demodulator Control Register (R5)  
Rev. A | Page 19 of 34  
 
 

Data Sheet  
Register 6—VCO Control and Enables  
The VCO amplitude can be controlled through Register 6. The  
VCO amplitude setting can be controlled between 0 and 31  
decimal, with a default value of 24.  
With R6[2:0] set to 110, the VCO control and enables register is  
programmed as show

The internal VCO can be disabled using Register 6. The internal  
VCO LDO can be disabled if an external clean 3.0 V supply is  
available.  
VCO band selection is normally selected based on BANDCAL  
calibration; however, the VCO band can be selected directly using  
Register 6. The VCO BS SRC determines whether the BANDCAL  
calibration determines the optimum VCO tuning band or if the  
external SPI interface is used to select the VCO tuning band  
based on the value of the VCO band select.  
The internal charge pump can be disabled through Register 6.  
Normally, the charge pump is enabled.  
CHARGE  
PUMP  
3.3V  
LDO  
VCO  
VCO LDO
 
VCO  
VCO  
CONTROL BITS  
DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0  
VCO BAND SELECT  
BS  
VCO AMPLITUDE  
ENABLE ENABLE SWITCH  
ENABLE ENABLE  
CSR  
DB23 DB22 DB21
 
DB20  
CPEN  
DB19  
L3EN  
DB18  
DB17  
DB16 DB15
 
DB14 DB13 DB12 DB11 DB10  
DB9  
0
0
0
LVEN VCO
 
EN VCO
 
SW VC5 VC4 VC3 VC2 VC1 VC0 VBSRC
 
VBS5 VBS4 VBS3 VBS2 VBS1 VBS0 C3(1) C2(1) C1(0)  
VCO BAND SELECT  
FROM SPI  
VBS5 VBS4 VBS3 VBS2 VBS1 VBS0  
0
0
0
0
0
0
0
…  
…  
…  
…  
…  
…  
…  
32 (DEFAULT)  
1
…  
0
…  
0
…  
0
…  
0
…  
0
…  
…  
63  
1
1
1
1
1
1
VBSRC VCO
 
BAND CAL AND SW SOURCE CONTROL  
0
1
BAND CAL (DEFAULT)  
SPI  
VCO AMPLITUDE  
VC5 VC4 VC3 VC2 VC1 VC0  
0
0
0
0
0
0
0
…  
…  
0
…  
0
…  
1
…  
0
…  
0
…  
0
8 (DEFAULT)  
…  
47  
…  
1
…  
0
…  
1
…  
1
…  
1
…  
1
…  
…  
1
…  
1
…  
1
…  
1
…  
1
…  
1
63 (RECOMMENDED)  
VCO SW
 
VCO SWITCH CONTROL FROM SPI  
REGULAR (DEFAULT)  
BAND CAL  
0
1
VCO EN
 
VCO ENABLE  
0
1
DISABLE  
ENABLE (DEFAULT)  
LVEN VCO
 
LDO ENABLE  
0
1
DISABLE  
ENABLE (DEFAULT)  
L3EN 3.3V
 
LDO ENABLE  
0
1
DISABLE  
ENABLE (DEFAULT)  
CHARGE PUMP ENABLE  
CPEN  
DISABLE  
ENABLE (DEFAULT)  
0
1
Figure 39. VCO Control and Enables (R6)  
Rev. A | Page 20 of 34  
 

Data Sheet  
APPLICATIONS INFORMATION  
BASIC CONNECTIONS  
SYNTHESIZER CONNECTIONS  
The basic circuit connections for a typical ADRF6801 application  
are shown i

The ADRF6801 includes an on-board VCO and PLL for LO  
synthesis. An external reference must be applied for the PLL to  
operate. A 1 V p-p nominal external reference must be applied  
to Pin 6 through an ac coupling capacitor. The reference is  
compared to an internally divided version of the VCO output  
frequency to create a charge pump error current to control and  
lock the VCO. The charge pump output current is filtered and  
converted to a control voltage through the external loop filter  
that is then applied to the VTUNE pin (Pin 39). ADIsimPLL™  
can be a helpful tool when designing the external charge pump  
loop filter. The typical Kv of the VCO, the charge pump output  
current magnitude, and PFD frequency should all be considered  
when designing the loop filter. The charge pump current magnitude  
can be set internally or with an external RSET resistor connected to  
Pin 5 and ground, along with the internal digital settings applied to  

Path Control

section for more details).  
SUPPLY CONNECTIONS  
The ADRF6801 has several supply connections and on-board  
regulated reference voltages that should be bypassed to ground  
using low inductance bypass capacitors located in close proximity  
to the supply and reference pins of the ADRF6801. Specifically  
Pin 1, Pin 2, Pin 9, Pin 10, Pin 17, Pin 22, Pin 27, Pin 29, Pin 34,  
and Pin 40 should be bypassed to ground using individual bypass  
capacitors. Pin 40 is the decoupling pin for the on-board VCO  
LDO, and for best phase noise performance, several bypass  
capacitors ranging from 100 pF to 10 µF may help to improve  
phase noise performance. For additional details on bypassing the  
supply nodes, see the evaluation board schematic in

+5V  
CHARGE PUMP  
LOOP FILTER  
IF I-OUTPUT  
IF I-OUTPUT  
BALUN  
40  
39  
38  
37  
36  
35  
34  
33  
32  
31  
+5V  
VCC1  
30  
29  
GND  
+5V  
1
2
3
DECL3  
CPOUT  
VCCBB  
GND 28  
27  
26  
4
5
6
VCCRF  
RFIN  
GND  
+5V  
OPEN  
R2  
RSET  
RF INPUT  
ADRF6801  
EXTERNAL  
REFERENCE  
GND
R
F
2
5  
REFIN  
G
N
D  
7
8
9
24  
GND  
MONITOR  
OUTPUT  
G
N
D 23  
MUXO
U
T  
DECL2  
VCCBB  
GND  
22  
21  
+5V  
10  
VCC2  
+5V  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
SPI CONTROL  
IF Q-OUTPUT  
BALUN  
IF Q-OUTPUT  
+5V  
Figure 40. Basic Connections  
Rev. A | Page 21 of 34  
 
 
 
 
 

Data Sheet  
I/Q OUTPUT CONNECTIONS  
SETTING THE FREQUENCY OF THE PLL  
The ADRF6801 has I and Q baseband outputs. Each output  
stage consists of emitter follower output transistors with a low  
differential impedance of 24 Ω and can source up to 12 mA p-p  
differentially. A Mini-Circuits TCM9-1+ balun is used to trans-  
form a single-ended 50 Ω load impedance into a nominal 450 Ω  
differential impedance.  
The frequency of the VCO/PLL, once locked, is governed by the  
values programmed into the PLL registers, as follows:  
f

PLL

=
f

PFD

× 2 × (
INT
+
FRAC
/
MOD
)  
where:  
f
f

PLL

is the frequency at the VCO when the loop is locked.  

PFD

is the frequency at the input of the phase frequency detector.  
RF INPUT CONNECTIONS  
INT
is the integer divide ratio programmed into Register 0.  
MOD
is the modulus divide ratio programmed into Register 1.  
FRAC
is the fractional value programmed into Register 2.  
The ADRF6801 is to be driven single-ended and can be either dc  
coupled or ac coupled. There is an on-chip ground referenced  
balun that converts the applied single-ended signal to a differential  
signal that is then input to the RF V-to-I converter.  
The practical lower limit of the reference input frequency is  
determined by the combination of the desired f

PLL

and the maximum  
programmable integer divide ratio of 119 and reference input  
frequency multiplier of 2. For a maximum f

PLL

of 4600 MHz,  
CHARGE PUMP/VTUNE CONNECTIONS  
The ADRF6801 uses a loop filter to create the VTUNE voltage  
for the internal VCO. The loop filter in its simplest form is an  
integrating capacitor. It converts the current mode error signal  
coming out of the CPOUT pin into a voltage to control the VCO  
via the VTUNE voltage. The stock filter on the evaluation  
board has a bandwidth of 130 kHz. The loop filter contains  
seven components, four capacitors, and three resistors. Changing  
the values of these components changes the bandwidth of the loop  
filter. Note that to obtain the approximately 2.5 kHz loop band-  
width, the user can change the values of the following components  
on the evaluation board to as follows: C14 = 0.1 µ
F
,
R
10 = 68 Ω,  
C15 = 4.7 µ
F
,
R
9 = 270 Ω, C13 = 47 n
F
,
R
60 = 0 Ω, C4 = open.  
f

REF

> ~
f

PLL

/(119 × 2 × 2), or 9.7 MHz.  
A lock detect signal is available as one of the selectable outputs  
through the MUXOUT pin, with logic high signifying that the  
loop is locked.  
When the internal VCO is used, the actual LO frequency is  
f

LO

=
f

PLL

/4  
REGISTER PROGRAMMING  
Because Register 6 controls the powering of the VCO and  
charge pump, it must be programmed once before programming  
the PLL frequency (Register 0, Register 1, and Register 2).  
LO SELECT INTERFACE  
The registers should be programmed starting with the highest  
register first and then sequentially down to Register 0 last. When  
Register 0, Register 1, or Register 2 is programmed, an internal  
VCO calibration is initiated that must execute when the other  
registers are set. Therefore, the order must be Register 6, Register 5,  
Register 4, Register 3, Register 2, Register 1, and then Register 0.  
Whenever Register 0, Register 1, or Register 2 is written to, it  
initializes the VCO calibration (even if the value  
in these registers does not change). After the device has been  
powered up and the registers configured for the desired mode of  
operation, only Register 0, Register 1, or Register 2 must be  
programmed to change the LO frequency.  
The ADRF6801 has the option of either monitoring a scaled  
version of the internally generated LO (LOSEL pin driven high  
at 3.3 V) or providing an external LO source (LOSEL pin driven  
low to ground, the LDRV bit in Register 5 set low, and the LXL bit  
in Register 5 set high). See the

Descriptions

section for full operation details.  
EXTERNAL LO INTERFACE  
The ADRF6801 provides the option to use an external signal  
source for the LO into the IQ demodulating mixer core. It is  
important to note that the applied LO signal is divided down  
by either 2 or 4 depending on the LO path divider bit, LDI
V
,
i
n  
Register 5, prior to the actual IQ demodulating mixer core. The  
divider is determined by the register settings in the LO path  
and mixer control register (see the

Demodulator Control

section). The LO input pins (Pin 37 and  
Pin 38) present a broadband differential 50 Ω input impedance.  
The LOP and LON input pins must be ac-coupled. This is achieved  
on the evaluation board via a Mini-Circuits TC1-1-13+ balun with  
a 1:1 impedance ratio. When not in use, the LOP and LON pins  
can be left unconnected.  
If none of the register values is changing from their defaults,  
there is no need to program them.  
Rev. A | Page 22 of 34  
 
 
 
 
 
 
 

Data Sheet  
EVM MEASUREMENTS  
EVM is a measure used to quantify the performance of a digital  
radio transmitter or receiver. A signal received by a receiver has  
all constellation points at their ideal locations; however, various  
imperfections in the implementation (such as magnitude imbalance,  
noise floor, and phase imbalance) cause the actual constellation  
points to deviate from their ideal locations.  
The ADRF6801 shows excellent EVM performance for 16 QAM.  

Figure 41

shows the EVM of the ADRF6801 being better than  
−40 dB over a RF input range of about +35 dB for the 16 QAM  
modulated signal at a 10 MHz symbol rate. The pulse shaping  
filter
’
s
r
oll-off (alpha) was set to 0.35.  
0
In general, a demodulator exhibits three distinct EVM limitations  
vs. received input signal power. As signal power increases, the  
distortion components increase. At large enough signal levels,  
where the distortion components due to the harmonic non-  
linearities in the device are falling in-band, EVM degrades  
as signal levels increase. At medium signal levels, where the  
demodulator behaves in a linear manner and the signal is well  
above any notable noise contributions, the EVM has a tendency to  
reach an optimal level determined dominantly by either quadrature  
accuracy and I/Q gain match of the demodulator or the precision  
of the test equipment. As signal levels decrease, such that the  
noise is the major contribution, the EVM performance vs. the  
signal level exhibits a decibel-for-decibel degradation with  
decreasing signal level. At lower signal levels, where noise proves  
to be the dominant limitation, the decibel EVM proves to be  
directly proportional to the SNR.  
–5  
–10  
–15  
–20  
–25  
–30  
–35  
–40  
–45  
–65  
–55  
–45  
–35  
–25  
–15  
–5  
5
15  
INPUT POWER (dBm)  
Figure 41. EVM vs. Input Power, EVM Measurements at f

RF

= 900 MHz;  

IF

= 0 MHz (that is, Direct Down Conversion); 16 QAM; Symbol Rate = 10 MHz  
f
The basic test setup to test EVM for the ADRF6801 consisted  
of an Agilent E4438C, which was used as a signal source. The  
900 MHz modulated signal was driven single ended into the  
RFIN SMA connector of the ADRF6801 evaluation board. The  
IQ baseband outputs were taken differentially into two

difference amplifiers to convert the differential signals into single-  
ended signals. A Hewlett Packard 89410A VSA was used to sample  
and calculate the EVM of the signal. The ADRF6801 IQ base-  
band output pins were presented with a 450 Ω differential load  
impedance.  
Rev. A | Page 23 of 34  
 
 

Data Sheet  
EVALUATION BOARD LAYOUT AND THERMAL GROUNDING  
An evaluation board is available for testing the ADRF6801. The  
evaluation board schematic is shown in

provides  
the component values and suggestions for modifying the  
component values for the various modes of operation.  
1
2
VCC  
VCC_SENSE  
OSC_3P3V  
VCC_RF  
VCC_BB  
VCC_LO  
VCC4  
3
5
7
4
6
8
R55  
S1  
R29  
0Ω  
R32  
0Ω  
R31  
0Ω  
R13  
0Ω  
VCC  
10kΩ  
J1  
3P3V_SENSE  
2P5V_LDO  
R56  
VCC_SENSE  
VCC  
VCC_LO  
R33  
0Ω  
LO  
C28  
10µF  
OUTPUT_EN  
LO_EXTERN  
10kΩ  
LO_EXTERN  
R6  
0Ω  
9
10  
VTUNE  
VCO_LDO  
VCC  
VCC_LO  
OPEN  
R3  
R59  
OPEN  
C8  
100pF  
C7  
0.1µF  
IBBP  
R4  
0Ω  
R45  
R38  
R9  
R60  
CP  
T2  
R40  
0Ω  
3
4
0Ω  
10kΩ  
10kΩ  
0Ω  
IOUT_SE  
R10  
3kΩ  
4
3
5
2
OPEN R41  
P2  
2
C13  
6.8pF  
R46  
C14  
22pF  
C4  
22pF  
T1  
C15  
2.7nF  
1
5
0Ω  
R5  
0Ω  
1
R37  
0Ω  
OPEN  
R39  
R11  
R12  
0Ω  
IBBN  
R1  
0Ω  
OPEN  
VCO_LDO  
1nF 1nF  
C6 C5  
C30  
0.1µF  
3P3V1  
R15  
C2  
C1  
0Ω  
10µF 100pF  
R27  
0Ω  
R49  
OPEN  
3P3V_SENSE  
VCC_BB  
40  
39  
38  
37  
36  
35  
34  
33  
32  
31  
VCC4  
VCO_LDO  
C26  
100pF  
C27  
0.1µF  
R7  
VCC_RF  
VCC4  
VCC1  
1
2
3
GND 30  
0Ω  
R8  
VCC_RF  
R26  
0Ω  
C24  
100pF  
C9  
0.1µF  
C10  
DECL3  
CPOUT  
GND  
VCCBB 29  
GND 28  
100pF  
0Ω  
C12  
100pF  
C11  
0.1µF  
C25  
0.1µF  
4
5
6
7
8
9
VCCRF 27  
RFIN 26  
OPEN  
R2  
R28  
0Ω  
RFIN  
RSET  
ADRF6801  
C31  
1nF  
REFIN  
REFIN  
GND  
GNDRF 25  
GND 24  
R14  
49.9Ω  
VCC_BB1  
MUXOUT  
DECL2  
GND 23  
R16  
R25  
REFOUT  
VCCBB 22  
GND 21  
VCC_BB  
0Ω  
0Ω  
C22  
100pF  
C23  
0.1µF  
10 VCC2  
OPEN  
R23  
2P5V_LDO  
QBBP  
R18  
11  
13  
15  
17  
19  
12  
14  
16  
18  
20  
2P5V  
0Ω  
C3  
10µF  
C17  
0.1µF  
C16  
100pF  
R21  
0Ω  
D
A
TA  
R47  
T3  
R43  
0Ω  
LE  
3
4
QOUT_SE  
0Ω  
2
R44  
OPEN  
P3  
R58  
OPEN  
VCC  
R17  
C34  
R52  
OPEN  
R48  
C33  
OPEN  
R51  
OPEN  
VCC2  
OPEN  
1
5
0Ω  
0Ω  
R22  
0Ω  
C19  
0.1µF  
C18  
100pF  
CLK  
OPEN  
R42  
R57  
0Ω  
R30  
0Ω  
QBBN  
C29  
0.1µF  
C32  
R50  
OPEN  
OPEN  
S2  
R20  
R35  
0Ω  
R54  
0Ω  
VCC  
R53  
0Ω  
10kΩ  
OPEN  
R19  
OPEN  
R34  
OUTPUT_EN  
GND  
OPEN  
LEGEND  
VCC_LO  
R24  
1
2
3
4
5
NET NAME  
GND1  
GND2  
0Ω  
P1  
VCC_LO1  
C21  
100pF  
6
7
8
9
TEST POINT  
C20  
0.1µF  
SMA INPUT/OUTPUT  
DIG_GND  
VTUNE  
R36  
0Ω  
Figure 42. Evaluation Board Schematic  
Rev. A | Page 24 of 34  
 
 

Data Sheet  
The package for the ADRF6801 features an exposed paddle on  
the underside that should be well soldered to an exposed  
opening in the solder mask on the evaluation board.

illustrates the dimensions used in the layout of the ADRF6801  
footprint on the ADRF6801 evaluation board (1 mil. = 0.0254 mm).  
Note the use of nine via holes on the exposed paddle. These  
ground vias should be connected to all other ground layers on  
the evaluation board to maximize heat dissipation from the device  
package. Under these conditions, the thermal impedance of the  
ADRF6801 was measured to be approximately 30°C/W in still air.  
0.012  
0.035  
0.050  
0.168  
Figure 44. ADRF6801 Evaluation Board Top Layer  
0.025  
0.020  
0.177  
0.232  
Figure 43. Evaluation Board Layout Dimensions for the ADRF6801 Package  
Figure 45. ADRF6801 Evaluation Board Bottom Layer  
Table 5. Evaluation Board Configuration Options  
Component  
Function  
Default Condition  
VCC, VCC2, VCC4, VCO_LDO, VCC_LO,
 
Power supply, ground and other test points.  
VCC, VCC2, VCC4, VCC_LO, VCC_RF, VCC_BB1,  
VCC_LO1, VCO_LDO, 3P3V1, 2P5V =  
Components Corporation TP-104-01-02,  
C
P
,
L
E, CLK, DATA =  
VCC_LO1, VCC_R
F
,
V
CC_BB1, 3P3V1,  
2P5V, CLK, DATA, LE, C
P
,
D
IG_GND,  
GND, GND1, GND2  
Connect a 5 V supply to VCC.  
Components Corporation TP-104-01-06,  
GND, GND1, GND2, DIG_GND =  
Components Corporation TP-104-01-00  
R1, R6, R7, R8, R13, R15, R17, R18,  
R24, R25, R26, R27, R29, R31, R32,  
R36, R49  
Power supply decoupling. Shorts or power supply  
decoupling resistors.  
R1, R6, R7, R8 = 0 Ω (0402),  
R13, R15, R17 = 0 Ω (0402),  
R18, R24, R25, R26, R27 = 0 Ω (0402),  
R29, R31, R32 = 0 Ω (0402),  
R36 = 0 Ω (0402),  
Rev. A | Page 25 of 34  
 
 

Data Sheet  
Component  
Function  
Default Condition  
C1, C2, C3, C7, C8, C9, C10, C11, C12,  
C16, C17, C18, C19, C20, C21, C22,  
C23, C24, C25, C26, C27, C28  
The capacitors provide the required decoupling of  
the supply-related pins.  
C1, C8, C10, C12 = 100 pF (0402),  
C16, C18, C21, C22 = 100 pF (0402),  
C24, C26 = 100 pF (0402),  
C7, C9, C11 = 0.1 µF (0402),  
C17, C19, C20, C23 = 0.1 µF (0402),  
C25, C27 = 0.1 µF (0402),  
C3, C2 = 10 µF (0603), C28 = 10 µF (3216)  
T1, C5, C6  
External LO path. The T1 transformer provides  
single-ended-to-differential conversion. C5 and C6  
provide the necessary ac coupling.  
C5, C6 = 1 nF (0603),  
T1 = TC1-1-13+ Mini-Circuits  
R16, R14, R58, C31  
REFIN input path. R14 provides a broadband 50 Ω  
termination followed by C31, which provides the  
ac coupling into REFIN. R16 provides an external  
connectivity to the MUXOUT feature described in  
Register 4. R58 provides option for connectivity to  
the P1-6 line of a 9-pin D-sub connector for dc  
measurements.  
R14 = 49.9 Ω (0402),  
R16 = 0 Ω (0402),  
R58 = open (0402),  
C31 = 1 nF (0603)  
R2, R9, R10, R11, R12, R37, R38, R59,  
R60, C4, C14, C15, C13  
Loop filter component options. A variety of loop filter  
topologies is supported using component  
R12, R37, R38 = 0 Ω (0402),  
R59 = open (0402),  
R9, R60 = 10 kΩ (0402),  
R10 = 3 kΩ (0402),  
R2, R11 = open (0402),  
C13 = 6.8 pF (0402),  
C4, C14 = 22 pF (0402),  
C15 = 2.7 nF (1206)  
placements C4, C13, C14, C15, R9, R10, and R60. R38  
and R59 provide connectivity options to numerous  
test points for engineering evaluation purposes. R2  
provides resistor programmability of the charge  
pump current (see Register 4 description). R37  
connects the charge pump output to the loop filter.  
R12 references the loop filter to the VCO_LDO. Default  
values on board provide a loop filter bandwidth of  
roughly 130 kHz using a 26 MHz PFD frequency.  
R3, R4, R5, R21, R22, R23, R39, R40,  
R41, R42, R43, R44, R45, R46, R47,  
R48, C29, C30, T2, T3, P2, P3  
IF I/Q output paths. The T2 and T3 baluns provide a
 
R4, R5, R21, R22, = 0 Ω (0402),  
9:1 impedance transformation; therefore, with a 50 Ω
 
R40, R43, R45, R46 = 0 Ω (0402),  
load on the single-ended IOUT/QOUT side, the center
 
R47, R48 = 0 Ω (0402),  
tap side of the balun presents a differential 450 Ω  
R3, R23, R39, R41, R42, R44 = open (0402),  
to the ADRF6806. The center taps of the baluns are  
C29, C30, = 0.1 µF (0402),  
ac grounded through C29 and C30. The baluns create
 
T2, T3 = TCM9-1+ Mini-Circuits,  
a differential-to-single-ended conversion for ease  
of testing and use, but an option to have straight  
differential outputs is achieved via populating R3,  
R39, R23, and R42 with 0 Ω resistors and removing  
R4, R5, R21, and R22. P2 and P3 are differential  
measurement test points (not to be used as jumpers).  
P2, P3 = Samtec SSW-102-01-G-S  
R28  
RF input interface. R28 provides the single-ended  
RF input path to the on-chip RF input balun.  
R28 = 0 Ω (0402)  
R30, R35, R50, R51, R52, R57, C32,  
C33, C34, P1  
Serial port interface. A 9-pin D-sub connector (P1)  
is provided for connecting to a host PC or control  
hardware. Optional RC filters can be installed on  
the CLK, DATA, and LE lines to filter the PC signals  
through R50 to R52 and C32 to C34. CLK, DATA, and  
LE signals can be observed via test points for debug  
purposes. R58 provides a connection to the MUXOUT  
for sensing lock detect through the P1 connector.  
R30, R35, R57 = 0 Ω (0402),  
R50, R51, R52 = open (0402),  
C32, C33, C34 = open (0402),  
P1 = Tyco Electronics 5747840-3  
R33, R55, R56, S1  
LO select interface. The LOSEL pin, in combination  
with the LDRV and LXL bits in Register 5, controls  
R33 = 0 Ω (0402),  
R55, R56 = 10 kΩ (0402),  
whether the LOP and LON pins operate as inputs or
 
S1 = Samtec TSW-103-08-G-S  
outputs. A detailed description of how the LOSEL pin,  
LDRV bit, and the LXL bit work together to control  
the LOP and LON pins is found in

under the  
LOSEL pin description. Using the S1 switch, the  
user can pull LOSEL to a logic high (V

CC

/2) or a logic  
low (ground). Resistors R55 and R56 form a resistor  
divider to provide a logic high of V

CC

/2. LO select  
can also be controlled through Pin 9 of J1. The 0 Ω  
jumper, R33, must be installed to control LOSEL via J1.  
Rev. A | Page 26 of 34  

Data Sheet  
Component  
Function  
Default Condition  
J1  
Engineering test points and external control. J1 is a
 
J1 = Molex Connector Corp. 10-89-7102  
10-pin connector connected to various important  
points on the evaluation board that the user can  
measure or force voltages upon.  
R19, R20, R34, R53, R54, S2  
Provides ground connection for Pin 16.  
R20, R53 = 0 Ω (0402),  
R34, R54 = open (0402),  
R19 = open, S2 = open  
Rev. A | Page 27 of 34  

Data Sheet  
ADRF6801 SOFTWARE  
The ADRF6801 evaluation board can be controlled from PCs  
using a USB adapter board, which is also available from Analog  
Devices, Inc. The USB adapter evaluation documentation and  
ordering information can be found on the

product page. The basic user interfaces are shown

and  
Attempting to program
Ref Input Frequency
,
PFD Frequency
,  
VCO Frequency (2×LO)
,
LO Frequency
, or other values in
RF  
Section
launches the
Synth Form
window shown i

Using
Synth Form
, the user can specify values for
Local Oscillator  
Frequency (MHz)
and
External Reference Frequency (MHz)
.  
The user can also enable the LO output buffer and divider options  
from this menu. After setting the desired values, it is important  
to click
Upload all registers
for the new setting to take effect.  
The software allows the user to configure the ADRF6801 for  
various modes of operation. The internal synthesizer is controlled  
by clicking on any of the numeric values listed in
RF Section
.  
Figure 46. Evaluation Board Software Main Window  
Rev. A | Page 28 of 34  
 
 

Data Sheet  
Figure 47. Evaluation Board Software Synth Form Window  
Rev. A | Page 29 of 34  
 

Data Sheet  
CHARACTERIZATION SETUPS  

Figure 48

t

show the general characterization bench  
setups used extensively for the ADRF6801. The setup shown in  

Figure 48

was used to do the bulk of the testing. An automated  
Agilent VEE program was used to control the equipment over the  
IEEE bus. This setup was used to measure gain, input P1dB, output  
P1dB, input IP2, input IP3, IQ gain mismatch, IQ quadrature  
accuracy, and supply current. The evaluation board was used to  
perform the characterization with a Mini-Circuits TCM9-1+ balun  
on each of the I and Q outputs. When using the TCM9-1+ balun  
below 5 MHz (the specified 1 dB low frequency corner of the  
balun), distortion performance degrades; however, this is not  
the ADRF6801 degrading, merely the low frequency corner of  
the balun introducing distortion effects. Through this balun,  
the 9-to-1 impedance transformation effectively presented a 450 Ω  
differential load at each of the I and Q channels. The losses of the  
output baluns were de-embedded from all measurements.  
To
d
o phase noise and reference spur measurements, the setup  
shown in

was used. Phase noise was measured at the  
baseband output (I or Q) at a baseband carrier frequency of  
50 MHz. The baseband carrier of 50 MHz was chosen to allow  
phase noise measurements to be taken at frequencies of up to  
20 MHz offset from the carrier. The noise figure was measured  
using the setup shown in

at a baseband frequency  
of 10 MHz.  
Rev. A | Page 30 of 34  
 

Data Sheet  
IEEE  
R&S SMA100  
SIGNAL GENERATOR  
IEEE  
3dB  
RF1  
MINI-CIRCUITS  
ZHL-42W AMPLIFIER  
(SUPPLIED WITH +15V dc  
FOR OPERATION)  
R&S SMT03 SIGNAL GENERATOR  
AGILENT 11636A  
POWER DIVIDER  
(USED AS COMBINER)  
3dB  
REF  
3dB  
RF2  
IEEE  
3dB  
RF  
R&S SMT03 SIGNAL GENERATOR  
IEEE  
CH A  
CH B  
RF SWITCH MATRIX  
HP 8508A  
VECTOR  
VOLTMETER  
IEEE  
I CH  
6dB  
RF  
Q CH  
6dB  
AGILENT MXA  
SPECTRUM ANALYZER  
3dB  
IEEE  
AGILENT 34980A  
MULTIFUNCTION  
SWITCH  
(WITH 34950 AND 2×  
34921 MODULES)  
ADRF6801  
EVALUATION BOARD  
AGILENT DMM  
(FOR I
 
MEAS.)  
10-PIN  
CONNECTION  
(+5V V  
SUPPLY  
IEEE  
,
POS  
DC MEASURE)  
AGILENT E3631A  
POWER SUPPLY  
6dB  
9-PIN D-SUB CONNECTION  
(VCO AND PLL PROGRAMMING)  
REF  
IEEE  
IEEE  
Figure 48. General Characterization Setup  
Rev. A | Page 31 of 34  
 

Data Sheet  
IEEE  
AGILENT 8665B  
LOW NOISE SYN  
SIGNAL GENERATOR  
REF  
RF1  
AGILENT 346B  
NOISE SOURCE  
3dB  
RF  
RF SWITCH MATRIX  
10MHz  
IEEE  
LOW-PASS FILTER  
AGILENT N8974A  
NOISE FIGURE ANALYZER  
I CH  
6dB  
RF  
Q CH  
6dB  
AGILENT DMM  
(FOR I  
MEAS.)  
SUPPLY  
3dB  
IEEE  
AGILENT 34980A  
MULTIFUNCTION  
SWITCH  
(WITH 34950 AND 2×  
34921 MODULES)  
ADRF6801  
EVALUATION BOARD  
10-PIN  
CONNECTION  
(+5V V
 
1,  
IEEE  
POS  
DC MEASURE)  
AGILENT E3631A  
POWER SUPPLY  
6dB  
9-PIN D-SUB CONNECTION  
(VCO AND PLL PROGRAMMING)  
REF  
IEEE  
IEEE  
Figure 49. Noise Figure Characterization Setup  
Rev. A | Page 32 of 34  
 

Data Sheet  
IEEE  
R&S SMA100  
SIGNAL GENERATOR  
IEEE  
REF  
RF1  
R&S SMA100  
SIGNAL GENERATOR  
IEEE  
100MHz  
LOW-PASS FILTER  
3dB  
RF  
AGILENT E5052 SIGNAL SOURCE  
ANALYZER  
RF SWITCH MATRIX  
IEEE  
AGILENT MXA  
SPECTRUM ANALYZER  
I CH  
6dB  
RF  
Q CH  
6dB  
AGILENT DMM  
(FOR I  
MEAS.)  
SUPPLY  
3dB  
IEEE  
AGILENT 34980A  
MULTIFUNCTION  
SWITCH  
(WITH 34950 AND 2×  
34921 MODULES)  
ADRF6801  
EVALUATION BOARD  
10-PIN  
CONNECTION  
(+5V V
 
1,  
IEEE  
POS  
DC MEASURE)  
AGILENT E3631A  
POWER SUPPLY  
6dB  
9-PIN D-SUB CONNECTION  
(VCO AND PLL PROGRAMMING)  
IEEE  
REF  
IEEE  
IEEE  
Figure 50. Phase Noise Characterization Setup  
Rev. A | Page 33 of 34  
 

Data Sheet  
OUTLINE DIMENSIONS  
6.10  
6.00 SQ  
5.90  
0.60 MAX  
0.60 MAX  
PIN 1  
INDICATOR  
31  
30  
40  
1
5.85  
5.75 SQ  
5.65  
0.50  
BSC  
PIN 1  
INDICATOR  
4.25  
4.10 SQ  
3.95  
EXPOSED  
PAD  
(BOTTOM VIEW)  
10  
11  
21  
20  
0.50  
0.40  
0.30  
0.20 MIN  
TOP VIEW  
4.50 REF  
0.80 MAX  
0.65 TYP  
FOR PROPER CONNECTION OF  
THE EXPOSED PAD, REFER TO  
THE PIN CONFIGURATION AND  
FUNCTION DESCRIPTIONS  
12° MAX  
1.00  
0.85  
0.80  
0.05 MAX  
0.02 NOM  
SECTION OF THIS DATA SHEET.  
COPLANARITY  
0.08  
0.20 REF  
0.30  
0.23  
0.18  
SEATING  
PLANE  
COMPLIANT TO JEDEC STANDARDS MO-220-VJJD-2  
Figure 51. 40-Lead Lead Frame Chip Scale Package [LFCSP_VQ]  
6 mm × 6 mm Body, Very Thin Quad  
(CP-40-1)  
Dimensions shown in millimeters  
ORDERING GUIDE  
Ordering  
Quantity  
Model

1  

Temperature Range  
Package Description  
Package Option  
CP-40-1  
ADRF6801ACPZ-R7  
ADRF6801-EVALZ  
−40°C to +85°C  
40-Lead Lead Frame Chip Scale Package [LFCSP_VQ]  
Evaluation Board  
750  

1

Z = RoHS Compliant Part.  
©2011–2018 Analog Devices, Inc. All rights reserved. Trademarks and  
registered trademarks are the property of their respective owners.  
D09576-0-6/18(A)  
Rev. A | Page 34 of 34