The LM2937-2.5 and LM2937-3.3 are positive voltage regulators capable of supplying up to 500 mA of load current. Both regulators are ideal for converting a common 5-V logic supply, or higher input supply voltage, to the lower 2.5-V and 3.3-V supplies to power very-large-scale integrations (VLSI) ASICs and microcontrollers. Special circuitry has been incorporated to minimize the quiescent current to typically only 10 mA with a full 500-mA load current when the input to output voltage differential is greater than 5 V.
The LM2937 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 LM2937-2.5 and LM2937-3.3 include special compensation circuitry that relaxes ESR requirements. The LM2937 is stable for all ESR ratings less than 5 Ω. This allows the use of low ESR chip capacitors.
The regulators are also suited for automotive applications, with built in protection from reverse battery connections, two-battery jumps and up to +60 V/−50 V load dump transients. Familiar regulator features such as short circuit and thermal shutdown protection are also built in.
