Digitally-programmable LDO drops only 45mV at 3A
Dubbed LT3073, its output, set through three tri-level pads, can be: in 50mV increments from 500mV to 1.2V, in 100mV increments from 1.2 to 1.8V, and then 2, 2.5, 3, 3.3, or 4.2V.
Output tolerance is ±1.5% over line load and temperature, and there is ±2.5% output margining.
Typical drop-out is 45mV (3A Tj=25°C) and output noise with a 4.7µF reference bypass capacitor is 1.2µVrms (10Hz to 100kHz). Other noise characteristics are 3nV/√ spot noise at 10kHz and 7µVp-p 1/f noise (100mHz to 10Hz)
Power supply rejection ratio is 52dB at 1MHz, and the regulator is stable with ceramic output Capacitors of 10μF and above.
A tracking feature (left) is included to control an upstream switching regulator to maintain a constant voltage across the LT3073 when power dissipation needs to be minimised.
Current monitoring (±3% at 3A) is included and there is a power-good flag.
Built-in protections include under-voltage lock-out, internal current limit and thermal shutdown with hysteresis.
Packaging is 3 x 4mm 22pad LQFN (QFN footprint).
Analogue Devices sees it powering FPGAs, microprocessors, RF communication circuits and in other noise-sensitive supply applications.