PLL Delivers Ultra-Fine Tuning

Providing what the company claims to be the industry's finest resolution, the ADF4157 fractional-N phase-locked loop (PLL) synthesizer operates at frequencies up to 6-GHz on a power supply ranging from 2.7V to 3.3V. Operating current is 23 mA, 0.01 mA in power-down mode. The chip, available in either a 20-lead LFCSP or a 16-lead TSSOP, integrates a low-noise, digital phase-frequency detector, precision high-voltage charge pump, programmable reference divider, programmable charge pump currents, and a 25-bit fixed-modulus fractional divider. RF-output phase is programmable for applications that require a specific phase relationship between the output and reference. Other features include a three-wire interface that controls all chip registers, separate charge pump supply (VP) for extended VCO tuning, and a digital lock-detect function. In either package type, price is $3.21 each/1,000. ANALOG DEVICES, INC., Wilmington, MA. (800) 262-5643.