adf5002 Analog Devices, Inc., adf5002 Datasheet - Page 8

• Manufacturer Part Number: adf5002
• Description: 4 Ghz To 18 Ghz Divide-by-8 Prescaler Adf5002
• Manufacturer: Analog Devices, Inc.

ADF5002
APPLICATION CIRCUIT
The ADF5002 can be connected either single-ended or differ-
entially to any of the Analog Devices PLL family of ICs. It is
recommended that a differential connection be used for best
performance and to achieve maximum power transfer. The
application circuit shown in Figure 10 shows the ADF5002
used as the RF prescaler in a microwave 16 GHz PLL loop. The
ADF5002 divides the 16 GHz RF signal down to 2 GHz, which
is input differentially into the
topology, using the
tuning ranges typically required by microwave VCOs.
RFIN
6dB ATTENUATION PAD
VDD1
OP184
150Ω
ADF5002
PRESCALER
37Ω
GND
VDD2
op amp, is used to provide the wide
10pF
ADF4156
150Ω
RFOUT
RFOUT
16GHz OUT
Figure 10. ADF5002 Used as the RF Prescaler in a Microwave 16 GHz PLL Loop
0.1µF
PLL. An active filter
18Ω
DECOUPLING
INTEGRATED
18Ω
RFOUT
RF
RF
MICROWAVE
IN
IN
B
A
ADF4156
VCO
Rev. 0 | Page 8 of 12
PLL
VTUNE
CP
The positive input pin of the OP184 is biased at half the ADF4156
charge pump supply (V
simple resistor divider, ensuring sufficient decoupling close to
the +IN A pin of the OP184. This configuration, in turn, allows
the use of a single positive supply for the op amp. Alternatively,
to optimize performance by ensuring a clean bias voltage, a low
noise regulator such as the
resistor divider network or the +IN A pin directly.
820pF
220Ω
V
P
/2
330Ω
1µF
OP AMP
OP184
1.8nF
P
). This can be easily achieved using a
47nF
ADP150
can be used to power the
1kΩ
1.8nF