–20V, 200mA, Ultralow Noise, Ultrahigh PSRR Negative Linear Regulator

The LT3093 is a high performance low dropout negative linear regulator featuring ADI’s ultralow noise and ultrahigh PSRR architecture for powering noise sensitive applications. The device can be easily paralleled to further reduce noise, increase output current and spread heat on a PCB.

The LT3093 supplies 200mA at a typical 190mV dropout voltage. Operating quiescent current is nominally 2.35mA and drops to 3µA in shutdown. The device’s wide output voltage range (0V to –19.5V) error amplifier operates in unity-gain and provides virtually constant output noise, PSRR, bandwidth, and load regulation independent of the programmed output voltage. Additional features are a bipolar enable pin, programmable current limit, fast startup capability and programmable power good to indicate output voltage regulation. The regulator incorporates a tracking function to control an upstream supply to maintain a constant voltage across the LT3093 to minimize power dissipation and optimize PSRR.

The LT3093 is stable with a minimum 4.7µF ceramic output capacitor. Built-in protection includes internal current limit with foldback and thermal limit with hysteresis. The LT3093 is available in thermally enhanced 12-Lead MSOP and 3mm × 3mm DFN Packages.

Applications

* RF and Precision Power Supplies

* Very Low Noise Instrumentation

* High Speed/High Precision Data Converters

* Medical Applications: Diagnostics and Imaging

* Post-Regulator for Switching Supplies

* Ultralow RMS Noise: 0.8µVRMS (10Hz to 100kHz)

* Ultralow Spot Noise: 2.2nV/√Hz at 10kHz

* Ultrahigh PSRR: 73dB 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

* Programmable Current Limit