LT1129/LT1129-3.3/LT1129-5 Micropower Low Dropout Regulators with Shutdown FEATURES DESCRIPTION n 400mV Dropout Voltage The LT 1129/LT1129-3.3/LT1129-5 are micropower low n 700mA Output Current dropout regulators with shutdown. The devices are capable n 50A Quiescent Current of supplying 700mA of output current with a dropout n No Protection Diodes Needed voltage of 400mV at maximum output. Designed for use n Adjustable Output from 3.8V to 30V in battery-powered systems, the low quiescent current, n 3.3V and 5V Fixed Output Voltages 50A operating and 16A in shutdown, make them an ideal n Controlled Quiescent Current in Dropout choice. The quiescent current does not rise in dropout as n Shutdown it does with many other low dropout PNP regulators. n 16A Quiescent Current in Shutdown Other features of the LT1129 /LT1129-3.3/LT1129-5 include n Stable with 3.3F Output Capacitor the ability to operate with small output capacitors. They n Reverse Battery Protection are stable with only 3.3F on the output while most older n No Reverse Output Current devices require between 10F and 100F for stability. Also n Thermal Limiting the input may be connected to ground or a reverse voltage n Surface Mount SOT-223 and DD-Pak Packages without reverse current ow from output to input. This makes the LT1129/LT1129-3.3/LT1129-5 ideal for backup power situations where the output is held high and the APPLICATIONS input is at ground or reversed. Under these conditions, n Low Current Regulator only 16A will ow from the output pin to ground. The n Regulator for Battery-Powered Systems devices are available in 5-lead TO-220, 5-lead DD-Pak and n Post Regulator for Switching Supplies 3-lead SOT-223 packages. n 5V to 3.3V Logic Regulator L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION 5V Supply with Shutdown Dropout Voltage 0.6 5 1 5V OUT IN OUT 500mA 0.5 + LT1129-5 3.3F V > 5.5V IN 2 SOLID TANTALUM 0.4 SENSE 4 SHDN GND 0.3 3 0.2 V (PIN 4) OUTPUT SHDN 0.1 < 0.25 OFF > 2.8 ON 112935 TA01 NC ON 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 OUTPUT CURRENT (A) 112935 TA02 112935ff 1 DROPOUT VOLTAGE (V)LT1129/LT1129-3.3/LT1129-5 ABSOLUTE MAXIMUM RATINGS (Note 1) Input Voltage ...................................................... 30V* Storage Temperature Range .................. 65C to 150C Output Pin Reverse Current ................................. 10mA Operating Junction Temperature Range (Note 3) Sense Pin Current ................................................ 10mA LT1129C-X .......................................... 0C to 125C Adjust Pin Current ................................................ 10mA LT1129C-X Extended Temperature Range Sense Pin, Adjust Pin Reverse Voltage ............... 0.6V (Note 12) ....................................... 40C to 125C Shutdown Pin Input Voltage (Note 2) ......... 6.5V, 0.6V LT1129I-X(Note 12) ......................... 40C to 125C Shutdown Pin Input Current (Note 2) .................. 20mA LT1129MP-X(Note 12) ..................... 55C to 125C Output Short-Circuit Duration .......................... Inde nite Lead Temperature (Soldering, 10 sec) ..................300C * For applications requiring input voltage ratings greater than 30V, contact the factory. PIN CONFIGURATION TOP VIEW 1 20 GND GND GND 2 19 GND FRONT VIEW TOP VIEW GND 3 18 GND 5 V 4 GND IN GND 17 OUTPUT 1 8 V IN 4 SHDN SENSE/ GND 5 16 GND TAB 2 7 GND ADJ* IS 3 GND 6 15 GND GND GND 3 6 GND GND 2 SENSE/ADJ* OUT 7 14 IN NC 4 5 SHDN 1 OUTPUT SENSE 8 13 SHDN S8 PACKAGE Q PACKAGE 9 GND GND 12 8-LEAD PLASTIC SO 5-LEAD PLASTIC DD GND 10 11 GND *PIN 2 = SENSE FOR LT1129-3.3/LT1129-5 *PIN 2 = SENSE FOR LT1129-3.3/LT1129-5 = ADJ FOR LT1129 = ADJ FOR LT1129 F PACKAGE = 60C/W = 30C/W JA 20-LEAD PLASTIC TSSOP JA NOTE: ALL GROUND PINS ARE INTERNALLY CONNECTED = 40C/W JA OBSOLETE PACKAGE FRONT VIEW FRONT VIEW 5 V IN 3 OUTPUT 4 SHDN TAB TAB IS 3 GND IS 2 GND GND GND 2 SENSE/ADJ* 1 1 OUTPUT V IN T PACKAGE ST PACKAGE 5-LEAD PLASTIC TO-220 3-LEAD PLASTIC SOT-223 *PIN 2 = SENSE FOR LT1129-3.3/LT1129-5 = ADJ FOR LT1129 = 50C/W JA = 50C/W JA ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT1129CS8 PBF LT1129CS8 TRPBF 1129 8-Lead Plastic SO 0C to 125C LT1129IS8 PBF LT1129IS8 TRPBF 1129I 8-Lead Plastic SO 40C to 125C LT1129CS8-3.3 PBF LT1129CS8-3.3 TRPBF 11293 8-Lead Plastic SO 0C to 125C LT1129IS8-3.3 PBF LT1129IS8-3.3 TRPBF 1129I3 8-Lead Plastic SO 40C to 125C LT1129CS8-5 PBF LT1129CS8-5 TRPBF 11295 8-Lead Plastic SO 0C to 125C 112935ff 2