Analog Devices intros high-res PLL for wireless apps

NORWOOD, USA: Analog Devices Inc. has announced the ADF4157, a 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. Design and simulation software, which greatly simplifies and streamlines loop filter design, is available free of charge as a download from Analog Devices’ Web site.

"ADI's PLL synthesizer portfolio now spans from 5-MHz to 8-GHz with more than 5 new PLLs released in the last year," said David Boylan, business director, RF Limerick, Analog Devices. "The PLLs are supported by the ADIsimPLL simulation design aid, which thousands of wireless systems designers are now using to speed their synthesizer developments."

Analog Devices is showcasing the ADF4157 at the European Microwave Conference, Oct. 8-12 in Munich, Germany (Booth #946), together with other innovations from ADI’s broad RF portfolio for applications including, wireless infrastructure, instrumentation, satellite communications and broadband access.

The ADF4157 operates up to 6GHz using a power supply ranging from 2.7V to 3.3V. The device can be powered down when not in use, resulting in overall system current reduction from 23mA to 0.01mA. 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 lock-detect function. The ADF4157 is fully pin-compatible with the ADF411x, ADF410x and ADF415x PLL synthesizers from Analog Devices.