ADF4207

a Dual RF PLL Frequency Synthesizers ADF4206/ADF4207/ADF4208 GENERAL DESCRIPTION FEATURES ADF4206: 550 MHz/550 MHz ADF4207: 1.1 GHz/1.1 GHz 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 The ADF4206 family of dual frequency synthesizers can be used to implement local oscillators in the upconversion and downconversion sections of wireless receivers and transmitters. Each synthesizer consists of a low-noise digital PFD (Phase Frequency Detector), a precision charge pump, a programmable reference divider, programmable A and B counters and a dualmodulus 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. The on-chip oscillator circuitry allows the reference input to be derived from crystal oscillators. A complete PLL (Phase-Locked Loop) can be implemented if the synthesizers are used with an external loop filter and VCOs (Voltage Controlled Oscillators). APPLICATIONS Wireless Handsets (GSM, PCS, DCS, CDMA, WCDMA) Base Stations for Wireless Radio (GSM, PCS, DCS, Control of all the on-chip registers is via a simple ...