LT1110 Micropower DC-DC Converter Adjustable and Fixed 5V, 12V FEATURES DESCRIPTIO n The LT1110 is a versatile micropower DC-DC converter. Operates at Supply Voltages From 1.0V to 30V n The device requires only three external components to Works in Step-Up or Step-Down Mode n deliver a fixed output of 5V or 12V. The very low minimum Only Three External Off-the-Shelf Components supply voltage of 1.0V allows the use of the LT1110 in Required n applications where the primary power source is a single Low-Battery Detector Comparator On-Chip n cell. An on-chip auxiliary gain block can function as a low User-Adjustable Current Limit n battery detector or linear post regulator. Internal 1A Power Switch n Fixed or Adjustable Output Voltage Versions The 70kHz oscillator allows the use of surface mount n Space-Saving 8-Pin MiniDIP or S8 Package inductors and capacitors in many applications. Quiescent current is just 300A, making the device ideal in remote or APPLICATI S battery powered applications where current consumption must be kept to a minimum. n Pagers n Cameras The device can easily be configured as a step-up or n Single-Cell to 5V Converters step-down converter, although for most step-down n Battery Backup Supplies applications or input sources greater than 3V, the LT1111 n Laptop and Palmtop Computers is recommended. Switch current limiting is user-adjustable n Cellular Telephones by adding a single external resistor. Unique reverse battery n Portable Instruments protection circuitry limits reverse current to safe, non- n Laser Diode Drivers destructive levels at reverse supply voltages up to 1.6V. n Hand-Held Inventory Computers TYPICAL APPLICATI All Surface Mount Efficiency Single Cell to 5V Converter 90 SUMIDA CD54-470K MBRS120T3 85 47H 5V V = 1.50V 80 IN 1 2 75 V = 1.25V IN I V LIM IN SW1 70 V = 1.00V 3 IN 1.5V LT1110-5 AA CELL* 65 SENSE 60 8 + GND SW2 15F TANTALUM 55 54 50 051105 2025 3035 40 OPERATES WITH CELL VOLTAGE 1.0V *ADD 10 F DECOUPLING CAPACITOR IF BATTERY LOAD CURRENT (mA) LT1110 TA01 IS MORE THAN 2 AWAY FROM LT1110. LT1110 TA02 1 EFFICIENCY (%) UO UO ULT1110 ABSOLUTEXAI U RATI GS PACKAGE/ORDER I FOR ATIO Supply Voltage, Step-Up Mode................................ 15V TOP VIEW ORDER PART Supply Voltage, Step-Down Mode ........................... 36V I 1 8 FB (SENSE)* NUMBER LIM SW1 Pin Voltage ...................................................... 50V V 2 SET 7 IN SW2 Pin Voltage ......................................... 0.5V to V IN LT1110CN8 SW1 3 6 A0 Feedback Pin Voltage (LT1110) .............................. 5.5V LT1110CN8-5 SW2 4 5 GND Switch Current ........................................................ 1.5A LT1110CN8-12 N8 PACKAGE Maximum Power Dissipation ............................. 500mW 8-LEAD PLASTIC DIP *FIXED VERSIONS Operating Temperature Range ..................... 0C to 70C T = 90C, = 130C/W JMAX JA Storage Temperature Range .................. 65C to 150C TOP VIEW Lead Temperature (Soldering, 10 sec.)................. 300C LT1110CS8 I 1 8 FB (SENSE)* LIM LT1110CS8-5 V 2 7 SET IN LT1110CS8-12 SW1 3 6 A0 S8 PART MARKING SW2 GND 4 5 S8 PACKAGE 1110 8-LEAD PLASTIC SOIC 11105 *FIXED VERSIONS T = 90C, = 150C/W 11012 JMAX JA Consult factory for Industrial and Military grade parts. ELECTRICAL CHARACTERISTICS T = 25C, V = 1.5V, unless otherwise noted. A IN SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS I Quiescent Current Switch Off l 300 A Q V Input Voltage Step-Up Mode l 1.15 12.6 V IN 1.0 12.6 V Step-Down Mode l 30 V Comparator Trip Point Voltage LT1110 (Note 1) l 210 220 230 mV V Output Sense Voltage LT1110-5 (Note 2) l 4.75 5.00 5.25 V OUT LT1110-12 (Note 2) l 11.4 12.00 12.6 V Comparator Hysteresis LT1110 l 48 mV Output Hysteresis LT1110-5 l 90 180 mV LT1110-12 l 200 400 mV f Oscillator Frequency l 52 70 90 kHz OSC DC Duty Cycle Full Load (V < V ) l 62 69 78 % FB REF t Switch ON Time l 7.5 10 12.5 s ON I Feedback Pin Bias Current LT1110, V = 0V l 70 150 nA FB FB I Set Pin Bias Current V = V l 100 300 nA SET SET REF V AO Output Low I = 300A, V = 150mV l 0.15 0.4 V AO AO SET Reference Line Regulation 1.0V V 1.5V l 0.35 1.0 %/V IN 1.5V V 12V l 0.05 0.1 %/V IN 2 U WU U W W W