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