Datasheet ADF5001 (Analog Devices) - 8

link to page 8
ADF5001 APPLICATION CIRCUIT
The ADF5001 can be connected either single-ended or differen- typically required by microwave VCOs. The positive input pin of tially to any of the Analog Devices PLL family of ICs. It is recom- the OP184 is biased at half the ADF4156 charge pump supply mended to use a differential connection for best performance (VP). This can be easily achieved using a simple resistor divider, and to achieve maximum power transfer. The application circuit ensuring sufficient decoupling close to the +IN A pin of the shown in Figure 10 shows the ADF5001 used as the RF prescaler OP184 thereby allowing the use of a single positive supply for the in a microwave 16 GHz PLL loop. The ADF5001 divides down op amp. Alternatively, to optimize performance by ensuring a the 16 GHz RF signal to 4 GHz, which is input differentially clean bias voltage, a low noise regulator like the ADP150 can be into the ADF4156 PLL. An active filter topology, using the used to power the resistor divider network or the +IN A pin OP184 op amp, is used to provide the wide tuning ranges directly.
1.8nF 10pF 0.1µF 330Ω 47nF VDD1 VDD2 ADF4156 DECOUPLING PLL INTEGRATED ADF5001 RFOUT RFINA 220Ω RFIN CP PRESCALER 1kΩ OP184 RFOUT RF VP/2 INB OP AMP 820pF GND 1µF 1.8nF MICROWAVE 6dB PAD VCO 37Ω 18Ω RFOUT VTUNE 150Ω 150Ω 18Ω
10 0 2- 40
16GHz OUT
08 Figure 10. ADF5001 Used as the RF Prescaler in a Microwave 16 GHz PLL Loop Rev. A | Page 8 of 12 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION FUNCTIONAL BLOCK DIAGRAM TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS EVALUATION BOARD PCB PCB MATERIAL STACK-UP BILL OF MATERIALS APPLICATION CIRCUIT OUTLINE DIMENSIONS ORDERING GUIDE NOTES NOTES NOTES