LT1109 Micropower Low Cost DC/DC Converter Adjustable and Fixed 5V, 12V DESCRIPTIO FEATURES n Uses Off-the-Shelf Inductors The LT1109 is a simple step-up DC/DC converter. Avail- n Only 33H Inductor Required able in 8-pin SO, 3-lead TO-92 (fixed output only) or n Low Cost miniDIP packages, the devices require only three external n 3-Lead TO-92, SO8, or 8-Pin DIP components to construct a complete DC/DC converter. n Adjustable or Fixed 5V or 12V Output Current drain is just 320A at no load, making the device n 120kHz Oscillator ideal for cost-sensitive applications where standby cur- n Only Three External Components Required rent must be kept to a minimum. n 320A I Q The LT1109-5 can deliver 5V at 100mA from a 3V input n 1.6V Minimum Start-Up Voltage and the LT1109-12 can deliver 12V at 60mA from a 5V n Logic Controlled Shutdown input. The 8-pin versions also feature a logic controlled SHUTDOWN pin that turns off the oscillator when taken APPLICATI S low. The gated-oscillator design requires no frequency compensation components. The high frequency 120kHz n Flash Memory VPP Generators oscillator permits the use of small surface mount induc- n 3V to 5V Converters tors and capacitors. For a 5V to 12V at 120mA converter, n 5V to 12V Converters see the LT1109A. Foa a 5V to 12V at 200mA converter n Disk Drives with 20A shutdown current, see the LT1301. n PC Plug-In Cards n Peripherals n Battery-Powered Equipment TYPICAL APPLICATI All Surface Mount Output Voltage Flash Memory Program Output Flash Memory VPP Generator 15 = L1 V MBRS120T3 OUT V = 5V 33H IN 5V/DIV 12 3 OV SW V OUT 1 8 9 V V SENSE 12V IN IN SHUTDOWN 5V 80mA 5V/DIV LT1109CS8-12 6 + 7 C1** 1ms/DIV SHUTDOWN* 22F LT1109 TA02 GND 16V 3 4 SHUTDOWN PROGRAM LT1109 TA01 0 * 8-PIN PACKAGE ONLY 0 10 20 30 40 50 60 70 80 90 100 = L1 = SUMIDA CD54-330LC (I = 80mA) OUT COILTRONICS CTX33-1 (80mA) OUTPUT CURRENT (mA) MURATA-ERIE LQH4N330K (I = 50mA) LT1109 TPC01 OUT ISI LCS2414-330K (I = 50mA) OUT **C1 = MATSUO 267M1602226 OR EQUIVALENT 1 OUTPUT VOLTAGE (V) UO UO ULT1109 O ABS LUTEXAI U RATI GS (Voltages Referred to GND Pin) Supply Voltage (V ) .............................. 0.4V to 20V Operating Temperature Range ..................... 0C to 70C OUT SW Pin Voltage ..........................................0.4V to 50V Storage Temperature Range ................. 65C to 150C SHUTDOWN Pin Voltage......................................... 6.0V Lead Temperature (Soldering, 10 sec.)................. 300C Maximum Power Dissipation ............................. 300mW Switch Current ........................................................ 1.2A PACKAGE/ORDER I FOR ATIO TOP VIEW BOTTOM VIEW TOP VIEW 3 2 1 V 1 8 SENSE VIN 1 8 SENSE IN V SW GND NC 2 SHUTDOWN NC 2 7 SHUTDOWN OUT 7 SW 3 6 NC SW 3 6 NC GND 4 NC NC 5 GND 4 5 Z PACKAGE N8 PACKAGE S8 PACKAGE 3-LEAD TO-92 PLASTIC LT1109 POI01 8-LEAD PLASTIC DIP LT1109 PO102 8-LEAD PLASTIC SOIC LT1109 PO103 T = 100C, = 150C/W T = 100C, = 130C/W JMAX JA T = 100C, = 160C/W JMAX JA JMAX JA ORDER PART ORDER PART S8 PART ORDER PART NUMBER NUMBER MARKING NUMBER LT1109CS8 LT1109CN8 1109 LT1109CZ-5 LT1109CN8-5 LT1109CS8-5 10905 LT1109CZ-12 LT1109CN8-12 LT1109CS8-12 10912 ELECTRICAL CHARACTERISTICS T = 25C, V = 3V (LT1109CN8, LT1109CS8), unless otherwise specified. A IN SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS I Quiescent Current Switch Off l 320 550 A Q Minimum Start-Up Voltage 1.6 V at V Pin (Z Package) OUT V Input Voltage (N8, S8 Package) l3V IN Comparative Trip Point Voltage LT1109 l 1.20 1.25 1.30 V V Output Voltage LT1109-5 3V V 5V l 4.75 5.00 5.25 V OUT IN LT1109-12 3V V 12V l 11.52 12.00 12.55 V IN Comparator Hysteresis LT1109 l 8 12.5 mV Output Voltage Ripple LT1109-5 l 25 50 mV LT1109-12 l 60 120 mV f Oscillator Frequency 100 120 140 kHz OSC l 90 150 kHz t Switch ON Time 3.3 4.2 5.3 s ON l 3.0 5.5 s DC Duty Cycle Full Load l 45 50 60 % V Switch Saturation Voltage I = 500mA 0.4 0.7 V CESAT SW LT1109-5: V = 3V LT1109-12: V = 5V l 0.5 0.8 V IN IN 2 U WU U W W W