LT1109 Datasheet | Linear Technology

LT1109 Micropower Low Cost DC/DC Converter Adjustable and Fixed 5V, 12V Features s s s s s s s s s s DESCRIPTIO Uses Off-the-Shelf Inductors Only 33µH Inductor Required Low Cost 3-Lead TO-92, SO8, or 8-Pin DIP Adjustable or Fixed 5V or 12V Output 120k Hz Oscillator Only Three External ponents Required 320µA IQ 1.6V Minimum Start-Up Voltage Logic Controlled Shutdown The LT1109 is a simple step-up DC/DC converter. Available in 8-pin SO, 3-lead TO-92 (fixed output only) or mini DIP packages, the devices require only three external ponents to construct a plete DC/DC converter. Current drain is just 320µA at no load, making the device ideal for cost-sensitive applications where standby current must be kept to a minimum. The LT1109-5 can deliver 5V at 100m A from a 3V input and the LT1109-12 can deliver 12V at 60m A from a 5V input. The 8-pin versions also feature a logic controlled SHUTDOWN pin that turns off the oscillator when taken low. The gated-oscillator design requires no frequency pensation ponents. The high frequency 120k Hz oscillator permits the use of small surface mount inductors and capacitors. For a 5V to 12V at 120m A converter, see the LT1109A. Foa a 5V to 12V at 200m A converter with 20µA shutdown current, see the LT1301. APPLICATI s s s s s s s Flash Memory VPP Generators 3V to 5V Converters 5V to 12V Converters Disk Drives PC Plug-In Cards Peripherals Battery-Powered Equipment TYPICAL APPLICATI L1¦ 33µH 3 VIN 5V 1 SW VIN SENSE 8 MBRS120T3 All Surface Mount Flash Memory VPP Generator Output Voltage VIN = 5V 12 OUTPUT VOLTAGE (V) VOUT 12V 80m A 9 SHUTDOWN 5V/DIV 6 1ms/DIV - TA02 LT1109CS8-12 7 SHUTDOWN- GND 4 SHUTDOWN PROGRAM - TA01 + C1- - 22µF 16V - 8-PIN PACKAGE ONLY ¦ L1 = SUMIDA CD54-330LC (I OUT = 80m A) COILTRONICS CTX33-1 (80m A) MURATA-ERIE LQH4N330K (I OUT = 50m A) ISI LCS2414-330K (IOUT = 50m A) - - C1 = MATSUO 267M1602226 OR EQUIVALENT 0 0 10 20 30 40 50 60 70 80 90 100 OUTPUT CURRENT (m A) -...