Analog Devices has released ultra-low-noise LDO (low-dropout) regulators for RF (radio frequency) 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, defence electronics and other wideband applications. A user adjustable CBYP can significantly reduce low frequency 1/f noise (8 nV/rtHz at 100 Hz) for precision analogue 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 minimising the size of discrete filtering components normally needed.