The ADF4206/ADF4208 is a dual frequency synthesizer which can be used to implement local oscillators in the up-conversion and down-conversion sections of wireless receivers and transmitters. They consist of a low-noise digital PFD (Phase Frequency Detector), a precision charge pump, a programmable reference divider, programmable A and B counters and a dual-modulus prescaler (P/P+1). The A (6-bit) and B (11- 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 synthesizers are used with an external loop filter and VCO's (Voltage Controlled Oscillators). Note: The ADF4207 mentioned in the data sheet is an obsolete part. * ADF4206: 550 MHz/550 MHz * ADF4208: 2.0 GHz/1.1 GHz * 2.7 V to 5.5 V Power Supply * Selectable Charge Pump Supply (VP) Allows Extended Tuning Voltage in 3 V Systems * Selectable Charge Pump Currents * On-Chip Oscillator Circuit * Selectable Dual Modulus Prescaler * RF2: 32/33 or 64/65 * RF1: 32/33 or 64/65 * 3-Wire Serial Interface * Power-Down Mode