L4909
L4909 is EXTERNALLY ADJUSTABLE MULTIFUNCTION REGULATOR manufactured by STMicroelectronics.
DESCRIPTION
It is a monolithic Multifunction Voltage Regulator; it contains 3 regulators, (REG1, REG2, REG3) each one with an enable input and a feedback input, to allow the voltage setting via external resistive divider.
BLOCK DIAGRAM
REF THERMAL SHUTDOWN EN1 EN2 EN3 6 7 9 + ENABLE CONTROL + REFERENCE GENERATOR REG1 REG2 REG3 + REF+20%
+
3,13 +
VINA, VINB
+
REG1
- 2 1 +
VO1 FB1
5 OVER CURRENT CHECK 4
+
REG2
- 14 15 +
+
VO2 FB2
TRIG
+
REG3
8 +
- 11 10
VO3 FB3
D00AU1171
May 2000
1/7
PIN CONNECTION
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1
FB2 VO2 VINB N.C. VO3 FB3 EN3 GND EN2 EN1 OC TRIG VINA VO1 FB1
TAB CONNECTED TO PIN 8
D00AU1153
Table 1. Pin Description
No. Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Name FB1 Vo1 Vin A TRIG OC EN1 EN2 GND EN3 FB3 Vo3 N.C. Vin B Vo2 FB2 REG1 feedback voltage input REG1 output voltage Input DC supply voltage Trigger for external SCR (crowbar protection) Over current warning output REG1 enable input REG2 enable input Analog ground REG3 enable input REG3 feedback voltage input REG3 output voltage Not Connected Input DC supply voltage REG2 output voltage REG2 feedback voltage input Function
2/7
ABSOLUTE MAXIMUM RATINGS
Symbol Vin Io Voc VENx Top Tstg Parameter Vin A,Vin B input DC supply voltage Vo1, Vo2, Vo3 output currents OC output voltage ENx input voltage Operating temperature range Storage temperature Value 40 internally limited min (15, Vin) 15 0 to 70
- 40 to 150 V V o
Unit...
