5.5V, 3A, Ultra-Low Noise, High PSRR, 85mV Dropout Ultra-Fast Linear Regulator

The LT®3077 is a low voltage, ultra-low noise, and ultra-fast transient response linear regulator. The device supplies up to 3A with a typical dropout voltage of 85mV. A 4.7μF reference bypass capacitor decreases output voltage noise to 1.2μVRMS. The wide bandwidth and high PSRR permit the use of small ceramic capacitors, saving bulk capacitance and cost. The LT3077 is ideal for powering high-performance FPGAs, data converters, RF, and noise-sensitive signal chain applications.

The output voltage is digitally selectable in 50mV increments from 0.5V to 1.2V, 100mV increments from 1.2V to 1.8V, and discrete levels at 2V, 2.5V, 3V, 3.3V, and 4.2V. The LT3077’s unity-gain operation provides virtually constant output noise, PSRR, and bandwidth independent of the programmed output voltage.

Precision current limiting allows users to minimize input power supply size and cost. Built-in protection includes UVLO, internal current limit, and thermal shutdown with hysteresis. The LT3077 is available in a compact 18-lead (3mm x 3mm) LFCSP-RT package.

APPLICATIONS

* RF Power Supplies: PLLs, VCOs, Mixers, LNAs, PAs  * High Speed/High Precision Data Converters

* Low Noise Instrumentation  * Post-Regulator for Switching Supplies

* FPGA and DSP Power Supplies

* Medical Applications

* Ultra-low RMS Noise: 1.2μVRMS (10Hz to 100kHz)

* Ultra-low Spot Noise: 3.5nV/√ at 10kHz

* Ultra-low 1/f Noise: 7μVP-P from 0.1Hz to 10Hz

* High-Frequency PSRR: 50dB at 1MHz

* Ultra-fast Transient Response

* Dropout Voltage: 85mV Typical

* Digitally Programmable VOUT: 0.5V to 4.2V

* Output Tolerance: ±1.5% Over Line, Load, and Temperature