PLL Frequency Synthesizer

The ADF4107 Frequency Synthesizer CAN be used to implemen local Oscillators in the upconversion and downconversion sections of Wireless receivers and transmitters. It consists of a low noise digital PFD (phase frequency detector), a precision Charge Pump programmable reference divider, programmable A and B Counters and a dual-modulus prescaler (P/P + 1). The A (6-bit) and B (13-bit) Counters in conjunction with the dual-modulus prescaler (P/P + 1), implement an N divider (N = BP + A). In addition, the 14-bit reference Counter (R counter), allows selectable REFIN frequencies at the PFD input. A complete PLL (phase-locked loop) CAN be implemented if the synthesizer is used with an external loop Filter and VCO (voltage controlled oscillator). Its very high bandwidth means that frequency doublers CAN be eliminated in many high frequency systems, simplifying system architecture and reducing cost. By Analog Devices, Inc.