LT1307/LT1307B Single Cell Micropower 600kHz PWM DC/DC Converters FEATURES DESCRIPTIO n Uses Small Ceramic Capacitors The LT 1307/LT1307B are micropower, fixed frequency n 50m A Quiescent Current (LT1307) DC/DC converters that operate from an input voltage as n 1mA Quiescent Current (LT1307B) low as 1V. First in the industry to achieve true current n Operates with V as Low as 1V mode PWM performance from a single cell supply, the IN n 600kHz Fixed Frequency Operation LT1307 features automatic shifting to power saving Burst n Starts into Full Load Mode operation at light loads. High efficiency is main- n Low Shutdown Current: 3m A tained over a broad 100m A to 100mA load range. The n Low-Battery Detector LT1307B does not shift into Burst Mode operation at light n 3.3V at 75mA from a Single Cell loads, eliminating low frequency output ripple at the n Automatic Burst Mode Operation at expense of light load efficiency. The devices contain a low- Light Load (LT1307) battery detector with a 200mV reference and shut down to n Continuous Switching at Light Load (LT1307B) less than 5m A. No load quiescent current of the LT1307 is n Low V Switch: 295mV at 500mA 50m A and the internal NPN power switch handles a 500mA CESAT current with a voltage drop of just 295mV. U Unlike competitive devices, large electrolytic capacitors APPLICATIO S are not required with the LT1307/LT1307B in single cell n Pagers applications. The high frequency (600kHz) switching al- n Cordless Telephones lows the use of tiny surface mount multilayer ceramic n GPS Receivers (MLC) capacitors along with small surface mount induc- n Battery Backup tors. The devices work with just 10m F of output capaci- n Portable Electronic Equipment tance and require only 1m F of input bypassing. n Glucose Meters The LT1307/LT1307B are available in 8-lead MSOP, PDIP n Diagnostic Medical Instrumentation and SO packages. , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. TYPICAL APPLICATIO Single Cell to 3.3V Converter Efficiency L1 D1 10m H 90 C1: MURATA-ERIE GRM235Y5V105Z01 MARCON THCS50E1E105Z V SW IN TOKIN 1E105ZY5U-C103-F C1 3.3V LBI FB C2: MURATA-ERIE GRM235Y5V106Z01 80 1m F 75mA V = 1.5V MARCON THCS50E1E105Z IN R1 LT1307 TOKIN 1E106ZY5U-C304-F 1.5V 1.02M SHUTDOWN SHDN LBO CELL 1% V = 1V D1: MOTOROLA MBR0520L IN V GND C C2 70 L1: COILCRAFT D01608C-103 V = 1.25V R2 10m F IN SUMIDA CD43-100 100k 604k MURATA ERIE LQH3C100 1% 680pF FOR 5V OUTPUT: R1 = 1M, R2 = 329k 60 1307 F01 50 Figure 1. Single Cell to 3.3V Boost Converter 0.1 1 10 100 LOAD CURRENT (mA) 1307 TA01 1307fa 1 EFFICIENCY (%) U ULT1307/LT1307B ABSOLUTE AXI U RATI GS (Note 1) V , SHDN, LBO Voltage ......................................... 12V Junction Temperature...........................................125 C IN SW Voltage ............................................................. 30V Operating Temperature Range FB Voltage ....................................................... V + 1V Commercial (Note 2) ......................... 20 C to 70 C IN V Voltage ................................................................ 2V Industrial ........................................... 40 C to 85 C C LBI Voltage ............................................ 0V V 1V Storage Temperature Range ................ 65 C to 150 C LBI Current into FB Pin .............................................. 1mA Lead Temperature (Soldering, 10 sec)................. 300 C UUW PACKAGE/ORDER I FOR ATIO ORDER PART ORDER PART NUMBER NUMBER TOP VIEW TOP VIEW LT1307CMS8 LT1307CN8 V 1 8 LBO C V 1 8 LBO C LT1307BCMS8 LT1307CS8 FB 2 7 LBI FB 2 7 LBI LT1307IS8 SHDN 3 6 V IN SHDN 3 6 V IN 5 SW GND 4 LT1307BCS8 GND 4 5 SW MS8 PACKAGE LT1307BIS8 8-LEAD PLASTIC MSOP N8 PACKAGE S8 PACKAGE 8-LEAD PDIP 8-LEAD PLASTIC SO T = 125 C, q = 160 C/W JMAX JA MS8 PART MARKING S8 PART MARKING T = 125 C, q = 100 C/W (N8) JMAX JA T = 125 C, q = 120 C/W (S8) JMAX JA 1307 1307I LTIC 1307B 1307BI LTIB Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25 C. A Commercial Grade 0 C to 70 C. V = 1.1V, V = V , LT1307/LT1307B unless otherwise noted. IN SHDN IN SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS I Quiescent Current Not Switching (LT1307) l 50 90 m A Q Not Switching (LT1307B) l 1.0 1.5 mA V = 0V l 13 m A SHDN V Feedback Voltage l 1.20 1.22 1.24 V FB I FB Pin Bias Current (Note 3) V = V l 27 60 nA B FB REF Reference Line Regulation 1V V 2V (25 C, 0 C) 0.6 1.1 %/V IN 1V V 2V (70 C) 1.5 %/V IN 2V V 5V l 0.3 0.8 %/V IN Minimum Input Voltage 0.92 1 V Input Voltage Range l15V g Error Amp Transconductance D I = 5m A l 25 35 65 m mhos m A Error Amp Voltage Gain 25 C, 0 C 35 100 V/V V 70 C 30 V/V f Switching Frequency l 550 600 750 kHz OSC 1307fa 2 U WWW