GENERAL DESCRIPTION

The LT?3073 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).

FEATURES

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

? Ultra-low Spot Noise: 3nV/√ 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

? Input Range: 0.6V to 5.5V

? Digital Output Margining: ±2.5

? Stable with Ceramic Output Capacitors (10μF

Minimum)

? Parallel Multiple Devices for Higher Current

? VIOC Pin to Control Upstream Switching Converter

? Precision Enable/Under Voltage Lock Out (UVLO)

? Power Good (PG) Flag

? Temperature Monitor

? 22-Lead (3mm x 4mm) LQFN 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