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LT3042 - 20V, 200mA, Ultralow Noise, Ultrahigh PSRR RF Linear Regulator

The LT®3042 is a high performance low dropout linear regulator featuring LTC’s ultralow noise and ultrahigh PSRR architecture for powering noise sensitive RF applications. 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 <<1μA in shutdown. The LT3042’s wide output voltage range (0V to 15V) while maintaining unitygain 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 foldback and thermal limit with hysteresis. The LT3042 is available in thermally enhanced 10-Lead MSOP and 3mm × 3mm DFN packages.

Features Ultralow RMS Noise: 0.8μVRMS (10Hz to 100kHz) Ultralow Spot Noise: 2nV/√Hz at 10kHz Ultrahigh PSRR: 79dB at 1MHz Output Current: 200mA Wide Input Voltage Range: 1.8V to 20V Single Capacitor Improves Noise and PSRR 100μA SET Pin Current: ±1% Initial Accuracy Single Resistor Programs Output Voltage High Bandwidth: 1MHz Programmable Current Limit Low Dropout Voltage: 350mV Output Voltage Range: 0V to 15V Programmable Power Good Fast Start-Up Capability Precision Enable/UVLO Parallelable for Lower Noise and Higher Current Internal Current Limit with Foldback Minimum Output Capacitor: 4.7μF Ceramic Reverse Battery and Reverse Current Protection 10-Lead MSOP and 3mm × 3mm DFN Packages Typical Application

Applications RF Power Supplies: PLLs, VCOs, Mixers, LNAs Very Low Noise Instrumentation High Speed/High Precision Data Converters Medical Applications: Imaging, Diagnostics Precision Power Supplies Post-Regulator for Switching Supplies Packaging

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