The LM2937 500 mA Low Dropout Regulator is a positive voltage regulator capable of supplying up to 500 mA of load current. Use of a PNP power transistor provides a low dropout voltage characteristic. With a load current of 500 mA the minimum input to output voltage differential required for the output to remain in regulation is typically 0.5V (1V guaranteed maximum over the full operating temperature range). 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 3V. The LM2937 requires an output bypass capacitor for stability. As with most low dropout regulators, the ESR of this capacitor remains a critical design parameter, but the LM2937 includes special compensation circuitry that relaxes ESR requirements. The LM2937 is stable for all ESR below 3Ω. This allows the use of low ESR chip capacitors. Ideally suited for automotive applications, the LM2937 will protect itself and any load circuitry from reverse battery connections, two-battery jumps and up to +60V/−50V load dump transients. Familiar regulator features such as short circuit and thermal shutdown protection are also built in.
The LM2937 is a positive‑voltage regulator capable of delivering up to 500 mA with a low dropout voltage. It uses a PNP power transistor and includes built‑in short‑circuit, thermal overload and reverse‑battery protection, making it suitable for automotive and other demanding applications.
The document provides absolute maximum ratings, electrical characteristics, typical performance curves, package dimensions and detailed application hints such as external capacitor requirements and heatsinking guidelines.
| Typical Dropout Voltage | 0.5 V at full load |
|---|---|
| Maximum Input Voltage | 60 V |
| Operating Temperature Range | -40 °C to +125 °C |
| Output Capacitor ESR Limit | ≤ 3 Ω |
Typical dropout voltage is 0.5 V when delivering the full 500 mA.
It includes internal short‑circuit, thermal overload, reverse‑battery and input transient protection.