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