L4909

L4909 EXTERNALLY ADJUSTABLE MULTIFUNCTION REGULATOR ■ 3 OUTPUTS - Vo1 : output voltage variable from 5 to 12 V; limit current : 1.2 A. - Vo2 : output voltage variable from 5 to 12 V; limit current : 1.2 A. - Vo3 : output voltage variable from 5 to 12 V; limit current : 1.2 A. ■ ENABLE INPUT FOR EACH REGULATOR ■ FEEDBACK INPUT FOR EACH REGULATOR ■ SHORT CIRCUIT PROTECTION TO GROUND ■ OVERCURRENT WARNING ■ DRIVER FOR EXTERNAL SCR (CROWBAR PROTECTION) ■ THERMAL SHUTDOWN c u d u d o r P e EN1 t e l o EN2 EN3 s b O OC 6 7 9 REFERENCE GENERATOR THERMAL SHUTDOWN e t le When one output voltage is higher than 20% typ of its nominal value (for instance in case of input-to-output short circuit), the crowbar output pin is activated, triggering an external SCR (connected between input and ground) that blows the input line fuse. REF + REF+20% 3,13 + REG1 ENABLE CONTROL REG2 REG3 + 2 - 1 + VO1 FB1 + 5 + OVER CURRENT CHECK REG2 14 - 15 + TRIG VINA, VINB + REG1 + o r P o s b O - 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. ) s ( ct ) s t( Each regulator is current limited and furthermore an OR-ed warning signal is output (open collector, active low output) when the current in a regulator goes above an over-current threshold (1 A typ for any regulator). DESCRIPTION BLOCK DIAGRAM MULTIWATT15 VO2 FB2 + 4 + REG3 GND 8 + 11 10 VO3 FB3 D00AU1171 May 2000 1/7 L4909 PIN CONNECTION 15 FB2 14 VO2 13 VINB 12 N.C. 11 VO3 10 FB3 9 EN3 8 GND 7 EN2 6 EN1 5 OC 4 TRIG 3 VINA 2 VO1 1 FB1 TAB CONNECTED TO PIN 8 Table 1. Pin Description No. Pin Name 1 FB1 REG1 feedback voltage input 2 Vo1 REG1 output voltage 3 VinA Input DC supply voltage 4 TRIG Trigger for external SCR (crowbar protection) 5 OC Over current warning output 6 EN1 REG1 enable input 7 EN2 REG2 enable input 8 GND Analog ground 9 EN3 10 FB3 12 bs 13 O 2/7 Vo3 N.C. u d o r P e t e l o 11 e t le Function ) s ( ct REG3 enable input REG3 feedback voltage input REG3 output voltage Not Connected VinB Input DC supply voltage 14 Vo2 REG2 output voltage 15 FB2 REG2 feedback voltage input c u d D00AU1153 o s b O - o r P ) s t( L4909 ABSOLUTE MAXIMUM RATINGS Symbol Vin Parameter VinA,VinB input DC supply voltage Io Vo1, Vo2, Vo3 output currents Value Unit 40 V internally limited Voc OC output voltage min (15, Vin) V VENx ENx input voltage 15 V Top Operating temperature range Tstg Storage temperature 0 to 70 o C - 40 to 150 oC Value Unit THERMAL DATA Symbol Parameter RTH j-case Thermal Resistance Junction to Case 1.8 c u d o r P ) s t( °C/W ELECTRICAL CHARACTERISTICS (Cout = 100nF; Vin -Vo = 5V; Io = 10mA; Tcase = 25°C unless otherwise specified Symbol Vo1 Parameter Test Condition e t le REG1 output voltage range V(FB1) so Min. Typ. 5 1.32 V REG1 output current limit EN1=ON; Vin-Vo1