3A, Ultra-Low Noise, High PSRR, 45mV Dropout Ultra-Fast Linear Regulator

The LT3073 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 45mV. 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 LT3073 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 LT3073’s unity-gain operation provides virtually constant output noise, PSRR, bandwidth, and load regulation independent of the programmed output voltage. In addition, the LT3073 incorporates a unique tracking feature (VIOC) to control the upstream switching regulator to maintain a constant voltage across the LT3073 and minimize power dissipation.

A precision current monitor provides power monitoring for system energy management, while 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 LT3073 is available in a compact 22-lead (3mm X 4mm) LQFN package (Laminate package with QFN footprint).

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: 3nV/√Hz at 10kHz

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

* High-Frequency PSRR: 52dB at 1MHz

* Ultra-fast Transient Response

* Dropout Voltage: 45mV Typical

* Digitally Programmable VOUT: 0.5V to 4.2V

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

* Precision Current Monitor: ±3% accuracy at 3A

* Programmable Current Limit: ±3% at 3A