LT3073 Linear Regulator

ADI's LT3073 is a low voltage, ultra-low noise, and ultra-fast transient response linear regulator. The device supplies up to 3 A with a typical dropout voltage of 45 mV. A 4.7 μF reference bypass capacitor decreases output voltage noise to 1.2 μV_RMS. 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 50 mV increments from 0.5 V to 1.2 V, 100 mV increments from 1.2 V to 1.8 V, and discrete levels at 2 V, 2.5 V, 3 V, 3.3 V, and 4.2 V. 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 (3 mm x 4 mm) LQFN package (laminate package with QFN footprint).

The EVAL-LT3073-AZ evaluation board features the LT3073, a 3 A, ultra-low noise, high power-supply rejection ratio (PSRR), 45 mV dropout ultra-fast linear regulator. The input voltage (V_IN) range for the V_IN power is from 0.6 V to 5.5 V. There are jumpers to set a 3-bit trilevel code that determines the output voltage (V_OUT) at preprogrammed levels that range from 0.5 V to 4.2 V. The maximum output current is 3 A. The EVAL-LT3073-AZ requires an external BIAS voltage (V_BIAS) that is at least 1.2 V higher than V_OUT and is between 2.375 V and 5.5 V.