LT1121/LT1121-3.3/LT1121-5 Micropower Low Dropout Regulators with Shutdown FEATURES DESCRIPTION n 0.4V Dropout Voltage The LT 1121/LT1121-3.3/LT1121-5 are micropower low n 150mA Output Current dropout regulators with shutdown. These devices are ca- n 30A Quiescent Current pable of supplying 150mA of output current with a dropout n No Protection Diodes Needed voltage of 0.4V. Designed for use in battery-powered sys- n Adjustable Output from 3.75V to 30V tems, the low quiescent current, 30A operating and 16A n 3.3V and 5V Fixed Output Voltages in shutdown, makes them an ideal choice. The quiescent n Controlled Quiescent Current in Dropout current is well-controlled it does not rise in dropout as it n Shutdown does with many other low dropout PNP regulators. n 16A Quiescent Current in Shutdown Other features of the LT1121/LT1121-3.3/LT1121-5 include n Stable with 0.33F Output Capacitor the ability to operate with very small output capacitors. n Reverse Battery Protection They are stable with only 0.33F on the output while most n No Reverse Current with Input Low older devices require between 1F and 100F for stability. n Thermal Limiting Small ceramic capacitors can be used, enhancing manu- n Available in the 8-Lead SO, 8-Lead PDIP, 3-Lead facturability. Also the input may be connected to ground SOT-23 and 3-Lead TO-92 Packages or a reverse voltage without reverse current flow from output to input. This makes the LT1121 series ideal for backup power situations where the output is held high and APPLICATIONS the input is at ground or reversed. Under these conditions n Low Current Regulator only 16A will flow from the output pin to ground. n Regulator for Battery-Powered Systems L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear n Post Regulator for Switching Supplies Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION 5V Battery-Powered Supply with Shutdown Dropout Voltage 0.5 8 1 3.3V OUT IN OUT 150mA 0.4 + LT1121-3.3 1F 5V SOLID TANTALUM 0.3 5 SHDN GND 0.2 3 0.1 V (PIN 5) OUTPUT SHDN <0.25 OFF >2.8 ON 0 NC ON LT1121 TA01 80 0 20 40 60 100 120 140 160 OUTPUT CURRENT (mA) LT1121 TA02 1121fg 1 DROPOUT VOLTAGE (V)LT1121/LT1121-3.3/LT1121-5 ABSOLUTE MAXIMUM RATINGS (Note 1) Input Voltage Output Short-Circuit Duration ....................... Indefinite LT1121 .............................................................. 30V Operating Junction Temperature Range (Note 3) LT1121HV ............................................... +36V, 30V LT1121C-X ............................................ 0C to 125C Output Pin Reverse Current ................................. 10mA LT1121I-X ........................................ 40C to 125C Adjust Pin Current ................................................ 10mA Storage Temperature Range .................. 65C to 150C Shutdown Pin Input Voltage (Note 2) .......... 6.5V, 0.6V Lead Temperature (Soldering, 10 sec) ...................300C Shutdown Pin Input Current (Note 2) .................. 20mA PIN CONFIGURATION TOP VIEW PIN 2 = NC FOR LT1121-3.3/LT1121-5 * OUT IN FRONT VIEW BOTTOM VIEW 1 8 = ADJ FOR LT1121 PINS 6 AND 7 ARE FLOATING (NO ** NC/ADJ* 2 7 NC** 3 OUTPUT INTERNAL CONNECTION) ON THE GND 3 6 NC** IN GND OUT STANDARD S8 PACKAGE. TAB IS 2 GND PINS 6 AND 7 CONNECTED TO GROUND GND NC 4 SHDN 5 ON THE A VERSION OF THE LT1121 (S8 ONLY). CONNECTING PINS 6 AND 7 TO THE 1 V IN N8 PACKAGE GROUND PLANE WILL REDUCE THERMAL 8-LEAD PDIP RESISTANCE. SEE THERMAL RESISTANCE Z PACKAGE ST PACKAGE S8 PACKAGE TABLES IN THE APPLICATIONS INFORMATION 3-LEAD PLASTIC SOT-223 3-LEAD PLASTIC TO-92 8-LEAD PLASTIC SO SECTION. T = 150C, = 50C/W T = 150C, = 150C/W JMAX JA JMAX JA T = 150C, = 120C/W (N8, S8) JMAX JA T = 150C, = 70C/W (AS8) JMAX JA ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LT1121CN8 PBF LT1121CN8 TRPBF LT1121CN8 8-Lead Plastic PDIP 0C to 125C LT1121CN8-3.3 PBF LT1121CN8-3.3 TRPBF LT1121CN8-3.3 8-Lead Plastic PDIP 0C to 125C LT1121CN8-5 PBF LT1121CN8-5 TRPBF LT1121CN8-5 8-Lead Plastic PDIP 0C to 125C LT1121IN8 PBF LT1121IN8 TRPBF LT1121IN8 8-Lead Plastic PDIP 40C to 125C LT1121IN8-3.3 PBF LT1121IN8-3.3 TRPBF LT1121IN8-3.3 8-Lead Plastic PDIP 40C to 125C LT1121IN8-5 PBF LT1121IN8-5 TRPBF LT1121IN8-5 8-Lead Plastic PDIP 40C to 125C LT1121CS8 PBF LT1121CS8 TRPBF 1121 8-Lead Plastic S0 0C to 125C LT1121CS8-3.3 PBF LT1121CS8-3.3 TRPBF 11213 8-Lead Plastic S0 0C to 125C LT1121CS8-5 PBF LT1121CS8-5 TRPBF 11215 8-Lead Plastic S0 0C to 125C LT1121HVCS8 PBF LT1121HVCS8 TRPBF 1121HV 8-Lead Plastic S0 40C to 125C LT1121IS8 PBF LT1121IS8 TRPBF 1121I 8-Lead Plastic S0 40C to 125C LT1121IS8-3.3 PBF LT1121IS8-3.3 TRPBF 121I3 8-Lead Plastic S0 40C to 125C LT1121IS8-5 PBF LT1121IS8-5 TRPBF 121I5 8-Lead Plastic S0 40C to 125C LT1121HVIS8 PBF LT1121HVIS8 TRPBF 121HVI 8-Lead Plastic S0 40C to 125C LT1121ACS8 PBF LT1121ACS8 TRPBF 1121A 8-Lead Plastic S0 0C to 125C LT1121ACS8-3.3 PBF LT1121ACS8-3.3 TRPBF 1121A3 8-Lead Plastic S0 0C to 125C LT1121ACS8-5 PBF LT1121ACS8-5 TRPBF 1121A5 8-Lead Plastic S0 0C to 125C 1121fg 2