4 Application Information

The MIC37252 is a high-performance low-dropout voltage regulator suitable for moderate to high-current regulator applications. Its 550mV dropout voltage at full load makes it especially valuable in battery-powered systems and as high-efficiency noise filters in post-regulator applications. Unlike older NPN-pass transistor designs, where the minimum dropout voltage is limited by the base-to-emitter voltage drop and collector-to-emitter saturation voltage, dropout performance of the PNP output of these devices is limited only by the low V_CE saturation voltage.

A trade off for the low dropout voltage is a varying base drive requirement. Microchip’s Super βeta PNP® process reduces this drive requirement to only 2% to 5% of the load current.

The MIC37252 regulator is fully protected from damage due to fault conditions. Current limiting is provided. This limiting is linear; output current during overload conditions is constant. Thermal shutdown disables the device when the die temperature exceeds the maximum safe operating temperature. Transient protection allows device (and load) survival even when the input voltage spikes above and below nominal. The output structure of these regulators allows voltages in excess of the desired output voltage to be applied without reverse current flow.