DESCRIPTION

The UTC LM2937 is a positive voltage regulator capable of

supplying up to 500mA of load current. The use of a PNP power

transistor provides a low dropout voltage characteristic. With a load

current of 500mA 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 10mA with a full 500mA load current when the

input to output voltage differential is greater than 3V.

The UTC 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 UTC

LM2937 is stable for all ESR below 3Ω.This allows the use of low ESR

chip capacitors.

Ideally suited for automotive applications, the UTC 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.

 FEATURES

* Fully specified for operation over -40C~ +125C

* Output current in excess of 500mA

* Output trimmed for 5 tolerance under all operating conditions

* Typical dropout voltage of 0.5V at full rated load current

* Wide output capacitor ESR range, up to 3Ω

* Reverse battery protection

* Internal short circuit and thermal overload protection

* 60V input transient protection

* Mirror image insertion protection

* Built-in ON/OFF control function