Category: Clock and Timing
Analog Devices announced the ADF4157, a new high frequency, fractional-N PLL synthesizer for applications that require low phase noise and ultra-fine-tuning resolution, such as satellite communications, private mobile radios (PMR), instrumentation and wireless base station equipment, including those that support GSM, PCS, DCS, WiMAX, CDMA and W-CDMA networks. The 25-bit fixed-modulus divider provides for ultra-fine frequency resolution.
The ADF4157 operates up to 6-GHz using a power supply ranging from 2.7 V to 3.3 V. The device can be powered down when not in use, resulting in overall system current reduction from 23 mA to 0.01 mA. The ADF4157 consists of a low-noise digital phase-frequency detector (PFD), a precision high-voltage charge pump, a programmable reference divider, programmable charge pump currents and a 25-bit fixed-modulus fractional divider. Additionally, the RF output phase is programmable for applications that require a particular phase relationship between the output and the reference. A simple three-wire interface controls all of the on-chip registers. The ADF4157 also features separate VP for extended VCO tuning voltage and a digital.
