®
L4947
L4947R
5V-0.5A VERY LOW DROP REGULATOR WITH RESET
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 DE-
FINED 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
DESCRIPTION
The L4947/L4947R is a monolithic integrated cir-
cuit 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
BLOCK DIAGRAM
Pentawatt
ORDERING NUMBERS:
L4947
L4947R
could fall as low as 6V. Furthermore, it incorpo-
rates a complete range of protection circuits
against the dangerous overvoltages always pre-
sent on the battery rail of the car. The reset func-
tion makes the device particularly suited to supply
microprocessor based systems : a signal is avail-
able (after an externally programmable delay) to
reset the microprocessor at power-on phase ; at
power-off, this signal becomes low inhibiting the
microprocessor.
This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice.
June 2000
1/6
STMICROELECTRONICS [ STMICROELECTRONICS ]
