New Industry Products

ADI Reduces LDO Noise Spectral Density by 2X with Lowest Phase Noise for VCOs

November 06, 2013 by Jeff Shepard

Analog Devices, Inc. (ADI) announced today the release of ultra-low-noise LDO (low-dropout) regulators for RF signal devices. The ADM7150/1 operate from 4.5 V to 16 V, provide up to 800-mA of output current and support output voltages from 1.5 to 5.0 V. The LDOs achieve an output-NSD (noise spectral density) of 1.4 nV/rtHz from 10 kHz to 1 MHz, which significantly reduces VCO (voltage-controlled oscillator) phase noise in point-to-point microwave radios, satellite communications, defense electronics and other wideband applications. Additionally, a user adjustable CBYP can significantly reduce low frequency 1/f noise (8 nV/rtHz at 100 Hz) for precision analog front-end measurement systems.

In addition to ultra-low noise, the ADM7150/1 achieve line and load transient responses of 0.01%/V and 0.4%/A respectively with a 10-µF ceramic output capacitor. The new LDOs also feature high PSRR (power-supply rejection ratio) performance of greater than 90 dB from 1 kHz to 100 kHz, and greater than 60 dB at 1 MHz. This effectively filters dc-dc switching regulator ripple, saving space by minimizing the size of discrete filtering components normally needed.

The ADM7150/51 are offered in 3-mm x 3-mm 8-lead LFCSP and SOIC packages and include significant enhancements to the 2-mm x 2-mm LFCSP and TSOT-5 packaged ADM7160. In lots of 1,000 pieces, the ADM7150/51 cost $3.64 each while the earlier model ADM7160 costs $0.96 in similar quantities. The new devices operate from 4.5 V to 16 V and deliver 800 mA while the ADM7160 from 2.2 V to 5.5 V and provides up to 200 mA of output current.