LT1316 Micropower DC/DC Converter with Programmable Peak Current Limit FEATURES DESCRIPTION n Precise Control of Peak Switch Current The LT 1316 is a micropower step-up DC/DC converter n Quiescent Current: that operates from an input voltage as low as 1.5V. A 33A in Active Mode programmable input current limiting function allows pre- 3A in Shutdown Mode cise control of peak switch current. Peak switch current n Low-Battery Detector Active in Shutdown can be set to any value between 30mA and 500mA by n Low Switch V : 300mV at 500mA adjusting one resistor. This is particularly useful for CESAT n 8-Lead MSOP and SO Packages DC/DC converters operating from high source impedance n Operates with V as Low as 1.5V inputs such as lithium coin cells or telephone lines. IN n Logic Level Shutdown Pin The fixed off-time, variable on-time regulation scheme results in quiescent current of only 33A in active mode. U Quiescent current decreases to 3A in shutdown with the APPLICATIONS low-battery detector still active. n Battery Backup The LT1316 is available in 8-lead MSOP and SO packages. n LCD Bias n Low Power 48V to 5V/3.3V Converters , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATION 2-Cell to 5V Step-Up Converter Efficiency vs Load Current L1 D1 47H 5V 90 50mA 3.3V IN R1 65 1M V SW IN 1% 2.5V IN 8 7 SHDN FB 80 1.8V + IN + C2 C1 LT1316 2 CELLS 47F 47F 1 2 NC LBI LBO NC R2 R SET GND 324k 70 3 4 1% R5 10k 1% 60 D1: MOTOROLA MBR0520L 1316 TA01 0.1 1 10 100 L1: SUMIDA CD43-470 LOAD CURRENT (mA) 1316 TA02 1 EFFICIENCY (%) U ULT1316 ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER INFORMATION V Voltage .............................................................. 12V IN ORDER PART TOP VIEW SW Voltage ............................................... 0.4V to 30V NUMBER LBO 1 8 FB FB Voltage ..................................................... V + 0.3V IN LBI 2 7 SHDN 6 V R 3 LT1316CMS8 SET IN R Voltage ............................................................. 5V SET GND 4 5 SW SHDN Voltage ............................................................ 6V MS8 PACKAGE MS8 PART MARKING LBI Voltage ................................................................V 8-LEAD PLASTIC MSOP IN LBO Voltage ............................................................. 12V T = 125C, = 160C/W JMAX JA LTCD Maximum Switch Current ................................... 750mA Maximum Junction Temperature ......................... 125C ORDER PART TOP VIEW Operating Temperature Range NUMBER LBO FB 1 8 Commercial ............................................. 0C to 70C LBI 2 7 SHDN LT1316CS8 Extended Commercial (Note 1).......... 40C to 85C R 3 6 V LT1316IS8 SET IN Industrial (Note 2) .............................. 40C to 85C GND 4 SW 5 Storage Temperature Range ................. 65C to 150C S8 PART MARKING S8 PACKAGE Lead Temperature (Soldering, 10 sec).................. 300C 8-LEAD PLASTIC SO 1316 T = 125C, = 120C/W JMAX JA 1316I Consult factory for Military grade parts. ELECTRICAL CHARACTERISTICS Commercial grade 0C to 70C, Industrial grade 40C to 85C, V = 2V, V = V , T = 25C unless otherwise noted. (Notes 1, 2) IN SHDN IN A PARAMETER CONDITIONS MIN TYP MAX UNITS Minimum Operating Voltage 1.5 1.65 V Maximum Operating Voltage 12 V Quiescent Current V = 2V, Not Switching 33 45 A SHDN l 50 A Quiescent Current in Shutdown V = 0V, V = 2V l 35 A SHDN IN V = 0V, V = 5V l 710 A SHDN IN FB Pin Bias Current l 330 nA Line Regulation V = 1.8V to 12V l 0.04 0.15 %/V IN LBI Input Threshold Falling Edge l 1.1 1.17 1.25 V LBI Pin Bias Current l 320 nA LBI Input Hysteresis l 35 65 mV LBO Output Voltage Low I = 500A l 0.2 0.4 V SINK LBO Output Leakage Current LBI = 1.7V, LBO = 5V l 0.01 0.1 A SHDN Input Voltage High l 1.4 V SHDN Input Voltage Low l 0.4 V SHDN Pin Bias Current V = 5V l 2 5 A SHDN V = 0V l 1 3 A SHDN 2 U W U W U WW