L4947 Datasheet PDF - ST Microelectronics

●DESCRIPTION

●The L4947/L4947R is a monolithic integrated circuit in Pentawatt package specially designed to provide a stabilized supply voltage for automotive and industrial electronic systems. Thanks to its very low voltage drop, in automotive applications the L4947/L4947R can work correctly even during the cranking phase, when the battery voltage could fall as low as 6V. Furthermore, it incorporates a complete range of protection circuits against the dangerous overvoltages always present on the battery rail of the car. The reset function makes the device particularly suited to supply microprocessor based systems : a signal is available (after an externally programmable delay) to reset the microprocessor at power-on phase ; at power-off, this signal becomes low inhibiting the microprocessor.

●■ PRECISE OUTPUT VOLTAGE (5V ± 4%) OVER FULL TEMPERATURE RANGE (– 40 / 125 °C)

●■ VERY LOW VOLTAGE DROP (0.75Vmax) OVER FULL T RANGE

●■ OUTPUT CURRENT UP TO 500mA

●■ RESET FUNCTION

●■ POWER-ON RESET DELAY PULSE DEFINED BY THE EXTERNAL CAPACITOR

●■ + 80V LOAD DUMP PROTECTION

●■ – 80V LOAD DUMP PROTECTION

●■ REVERSE VOLTAGE PROTECTION

●■ SHORT CIRCUIT PROTECTION AND THER MAL SHUT-DOWN (with hysteresis)

●■ LOW START UP CURRENT