Ultra low-noise power supply ripple rejection LDO

Featuring ultra low-noise and ultra-high PSRR architecture for powering noise-sensitive RF applications, Linear Technology’s LT3042 high-performance, low-dropout, linear regulator is now available from Digi-Key. Designed as a precision current reference followed by a high-performance voltage buffer, the LT3042 can be easily paralleled to further reduce noise, increase output current, and spread heat on the PCB. The device supplies 200mA at a typical 350mV dropout voltage. Operating quiescent current is nominally 2mA and drops to less than 1µA in shutdown. The LT3042’s wide output voltage range (0V to 15V), while maintaining unity gain operation, provides virtually constant output noise, PSRR, bandwidth, and load regulation independent of the programmed output voltage. Additionally, the regulator features programmable current limit, fast start-up capability, and programmable power good to indicate output voltage regulation. The LT3042 is stable with a minimum 4.7µF ceramic output capacitor. Built-in protection includes reverse battery protection, reverse current protection, internal current limit with fold-back, and thermal limit with hysteresis. The LT3042 is available in thermally-enhanced 10-lead MSOP and 3mm × 3mm DFN packages.