ADF4360-8BCPZ Analog Devices Inc, ADF4360-8BCPZ Datasheet - Page 23

• Manufacturer Part Number: ADF4360-8BCPZ
• Description: IC SYNTHESIZER VCO 24-LFCSP
• Manufacturer: Analog Devices Inc
• Type: Fanout Distribution, Integer N Synthesizer (RF)r

Specifications of ADF4360-8BCPZ

• Pll: Yes
• Input: CMOS
• Output: Clock
• Number Of Circuits: 1
• Ratio - Input:output: 1:2
• Differential - Input:output: No/No
• Frequency - Max: 400MHz
• Divider/multiplier: Yes/No
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 24-LFCSP
• Frequency-max: 400MHz
• Pll Type: Frequency Synthesis
• Frequency: 400MHz
• Supply Current: 5mA
• Supply Voltage Range: 3V To 3.6V
• Digital Ic Case Style: LFCSP
• No. Of Pins: 24
• Operating Temperature Range: -40°C To +85°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: EVAL-ADF4360-8EBZ1 - BOARD EVALUATION FOR ADF4360-8
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

OUTPUT MATCHING
There are a number of ways to match the output of the
ADF4360-8 for optimum operation; the most basic is to use a
50 Ω resistor to V
connected in series, as shown in Figure 27. Because the resistor
is not frequency dependent, this provides a good broadband
match. The output power in the circuit below typically gives
−9 dBm output power into a 50 Ω load.
A better solution is to use a shunt inductor (acting as an RF
choke) to V
output power.
Experiments have shown that the circuit shown in Figure 28
provides an excellent match to 50 Ω over the operating range of
the ADF4360-8. This gives approximately 0 dBm output power
across the specific frequency range of the ADF4360-8 using the
recommended shunt inductor, followed by a 100 pF dc blocking
capacitor.
VCO.
Figure 28. Optimum ADF4360-8 Output Stage
Figure 27. Simple ADF4360-8 Output Stage
This gives a better match and, therefore, more
RF
RF
VCO
V
V
VCO
OUT
VCO
OUT
. A dc bypass capacitor of 100 pF is
51Ω
L
100pF
100pF
50Ω
50Ω
Rev. A | Page 23 of 24
The recommended value of this inductor changes with the VCO
center frequency. A graph of the optimum inductor value vs.
frequency is shown in Figure 29.
Both complementary architectures can be examined using the
EVAL-ADF4360-8EB1 evaluation board. If the user does not
need the differential outputs available on the ADF4360-8, the
user should either terminate the unused output or combine
both outputs using a balun. Alternatively, instead of the LC
balun, both outputs may be combined using a 180° rat-race
coupler.
300
250
200
150
100
50
0
0
Figure 29. Optimum ADF4360-8 Shunt Inductor
100
CENTRE FREQUENCY (MHz)
200
300
ADF4360-8
400
5000