LT1107 Micropower DC/DC Converter Adjustable and Fixed 5V, 12V FEATURES DESCRIPTIO n Operates at Supply Voltages from 2V to 30V The LT 1107 is a versatile micropower DC/DC converter. n Consumes Only 320m A Supply Current The device requires only three external components to n Works in Step-Up or Step-Down Mode deliver a fixed output of 5V or 12V. Supply voltage ranges n Only Three External Components Required from 2V to 12V in step-up mode and to 30V in step-down n Low-Battery Detector Comparator On-Chip mode. The LT1107 functions equally well in step-up, step- n User Adjustable Current Limit down, or inverting applications. n Internal 1A Power Switch The LT1107 is pin-for-pin compatible with the LT1111, but n Fixed or Adjustable Output Voltage Versions has a duty cycle of 70%, resulting in increased output n Space Saving 8-Pin MiniDIP or SO-8 Package current in many applications. The LT1107 can deliver U 150mA at 5V from a 2AA cell input and 5V at 300mA from APPLICATIO S 24V in step-down mode. Quiescent current is just 320m A, making the LT1107 ideal for power-conscious battery- n Palmtop Computers operated systems. The 63kHz oscillator is optimized to n 3V to 5V, 5V to 12V Converters work with surface mount inductors and capacitors. n 24V to 5V, 12V to 5V Converters n Switch current limit can be programmed with a single LCD Bias Generators n resistor. An auxiliary gain block can be configured as a Peripherals and Add-On Cards n low-battery detector, linear post regulator, undervoltage Battery Backup Supplies n lock-out circuit, or error amplifier. Cellular Telephones n , LTC and LT are registered trademarks of Linear Technology Corporation Portable Instruments TYPICAL APPLICATIO Palmtop Computer Logic Supply Efficiency L1* 82 MBRS120T3 33m H V = 3V 5V IN 80 150mA 78 47W V = 2V IN 76 V = 2.5V I V IN IN LIM 74 2 AA SW1 + + ALKALINE 47m F 100m F LT1107-5 72 CELLS SENSE 70 GND SW2 68 66 64 * SUMIDA CD54-330K 1107 TA01 1 10 100 400 COILCRAFT DT3316-473 LOAD CURRENT (mA) 1107 TA02 1107fa 1 EFFICIENCY (%) U ULT1107 ABSOLUTEXAI U RATI GS (Note 1) Supply Voltage (V ) ............................................... 36V Maximum Switch Current ...................................... 1.5A IN SW1 Pin Voltage (V ) ......................................... 50V Operating Temperature Range SW1 SW2 Pin Voltage (V ) ............................ 0.5V to V LT1107C................................................ 0 C to 70 C SW2 IN Feedback Pin Voltage (LT1107) ................................ 5V LT1107I ............................................ 45 C to 85 C Sense Pin Voltage (LT1107-5, LT1107-12) ............ 36V LT1107M(OBSOLETE) ...............55 C to 125 C Maximum Power Dissipation ............................ 500mW Storage Temperature Range ................. 65 C to 150 C Set Pin Voltage ...................................................... 5.5V Lead Temperature (Soldering, 10 sec).................. 300 C PACKAGE/ORDER I FOR ATIO ORDER PART ORDER PART TOP VIEW NUMBER NUMBER I 1 8 FB (SENSE)* LIM TOP VIEW LT1107CN8 LT1107CS8 V 2 7 SET IN LT1107CN8-5 SW1 3 AO LT1107CS8-5 6 I 1 8 FB(SENSE)* LIM LT1107CN8-12 LT1107CS8-12 SW2 4 5 GND V 2 7 SET IN LT1107IS8 SW1 AO 3 6 N8 PACKAGE 8-LEAD PLASTIC DIP SW2 GND 4 5 * FIXED VERSIONS S8 PART MARKING T = 90 C, q = 130 C/W (N) S8 PACKAGE JMAX JA 8-LEAD PLASTIC SO J8 PACKAGE 1107 LT1107MJ8 *FIXED VERSIONS 8-LEAD CERAMIC DIP 11075 T = 90 C, q = 150 C/W LT1107MJ8-5 JMAX JA T = 150 C, q = 120 C/W (J) JMAX JA 110712 LT1107MJ8-12 1107I OBSOLETE PACKAGE Consider the N8 Package for Alternate Source Consult LTC Marketing for parts specified with wider operating temperature ranges. LECTR AL CHARACTERIST The l denotes the specifications which apply over the full operating E IC ICS temperature range, V = 3V, military or commercial version, T = 25 C, unless otherwise noted. IN A SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS I Quiescent Current Switch OFF 320 450 m A Q Quiescent Current, Step-Up Mode Configuration No Load LT1107-5 360 m A LT1107-12 550 m A V Input Voltage Step-Up Mode l 2 12.6 V IN Step-Down Mode l 30.0 V Comparator Trip Point Voltage LT1107 (Note 2) l 1.2 1.25 1.3 V V Output Sense Voltage LT1107-5 (Note 3) l 4.75 5 5.25 V OUT LT1107-12 (Note 3) l 11.40 12 12.60 V Comparator Hysteresis LT1107 l 8 12.5 mV Output Hysteresis LT1107-5 l 32 50 mV LT1107-12 l 75 120 mV f Oscillator Frequency 50 63 77 kHz OSC Duty Cycle, Step-Up Mode Full Load 64 70 76 % t Switch ON Time, Step-Up Mode I Tied to V 8.8 11 12.7 m s ON LIM IN 1107fa 2 U WU U W W W