Linear Voltage Regulator, Fixed, 4.75V To 26V In, 3.3V And 400mA Out, SOT-223-4 - 

The LM2937IMP-3.3/NOPB is a positive Voltage Regulator, capable of supplying up to 500mA of load current. This regulator is ideal for converting a common 5V logic supply or higher input supply voltage, to the lower 2.5 and 3.3V supplies to power very-large-scale integrations (VLSI) ASICs and microcontrollers. Special circuitry has been incorporated to minimize the quiescent current to typically only 10mA with a full 500mA load current when the input to output voltage differential is greater than 5V. It requires an output bypass capacitor for stability. As with most regulators utilizing a PNP pass transistor, the ESR of this capacitor remains a critical design parameter, but the regulator include special compensation circuitry that relaxes ESR requirements. It is stable for all ESR ratings less than 5Ω. This allows the use of low ESR chip capacitors.