500mA LOW DROPOUTVOLTAGE REGULATOR
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 |
