LT1300CN8#PBF Analog Devices

LT1300 Micropower High Efficiency 3.3/5V Step-Up DC/DC Converter DESCRIPTION FEATURES n Up to 220mA Output Current at 5V from 2V Supply The LT1300 is a micropower step-up DC/DC converter that n Supply Voltage as Low as 1.8V utilizes Burst Mode operation. The device can deliver 5V n Up to 88% Efficiency or 3.3V from a two-cell battery input. It features program- n Small Inductor 10H mable 5V or 3.3V output via a logic-controlled input, no- n 120A Quiescent Current load quiescent current of 120A and a shutdown pin which n Shutdown to 10A reduces supply current to 10A. The on-chip power switch n Programmable 3.3V or 5V Output has a low 170mV saturation voltage at a switch current of n I Pin Programs Peak Switch Current 1A, a four-fold reduction over prior designs. A 155kHz LIM n Low V Switch: 170mV at 1A Typical internal oscillator allows the use of extremely small sur- CESAT n Uses Inexpensive Surface Mount Inductors face mount inductors and capacitors. Operation is guaran- n 8-Lead DIP or SOIC Package teed at 1.8V input. This allows more energy to be extracted U from the battery increasing operating life. The I pin can LIM APPLICATIONS be used to program peak switch current with a single n resistor allowing the use of less expensive and smaller Palmtop Computers n inductors and capacitors in lighter load applications. The Portable Instruments n LT1300 is available in an 8-lead SOIC package, minimizing Bar-Code Scanners n board space requirements. For a 5V/12V Selectable Out- DC/DC Converter Module Replacements n put Converter see the LT1301. For increased output cur- Battery Backup Supplies n rent see the LT1302. Personal Digital Assistants n Burst Mode is a trademark of Linear Technology Corporation. PCMCIA Cards TYPICAL APPLICATIONS N Two-Cell to 3.3V/5V Step-Up Converter 5V Output Efficiency L1 10H D1 5V/3.3V 90 OUTPUT 67 88 V SW IN V = 4.0V IN 4 5V/3.3V 2 SELECT SENSE 86 SELECT 2 + C1 V = 3.0V IN AA LT1300 84 100F + C1 CELL V = 2.5V 100F IN 3 5 82 SHUTDOWN SHDN I N/C LIM V = 2.0V PGND GND IN 80 81 78 76 LT1300 TA1 L1 = COILCRAFT DO1608-103 OR SUMIDA CD54-100 74 1 10 100 500 C1 = AVX TPSD107M010R0100 OR SANYO OS-CON 16SA100M LOAD CURRENT (mA) LT1300 TA2 D1 = MBRS130LT3 OR 1N5817 1 EFFICIENCY (%) U ULT1300 ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER INFORMATION V Voltage .............................................................. 10V IN ORDER PART TOP VIEW SW1 Voltage ............................................................ 20V NUMBER GND PGND 1 8 Sense Voltage .......................................................... 10V SEL 2 7 SW SHUTDOWN Voltage................................................ 10V LT1300CN8 SHDN 3 6 V IN SELECT Voltage ....................................................... 10V LT1300CS8 SENSE 4 I 5 LIM I Voltage ............................................................ 0.5V LIM N8 PACKAGE Maximum Power Dissipation ............................. 500mW S8 PACKAGE 8-LEAD PLASTIC DIP S8 PART MARKING 8-LEAD PLASTIC SOIC Operating Temperature Range ..................... 0C to 70C Storage Temperature Range ................. 65C to 150C T = 100C, = 150C/ W 1300 JMAX JA Lead Temperature (Soldering, 10 sec).................. 300C Consult factory for Industrial grade parts. ELECTRICAL CHARACTERISTICS T = 25C, V = 2V unless otherwise noted. A IN SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS I Quiescent Current V = 0.5V, V = 5V, V = 5.5V l 120 200 A Q SHDN SEL SENSE V = 1.8V l 715 A SHDN V Input Voltage Range 1.8 V IN l 2.0 V V Output Sense Voltage V = 5V l 4.80 5.0 5.20 V OUT SEL V = 0V l 3.15 3.3 3.45 V SEL Output Referred V = 5V (Note 1) l 22 50 mV SEL Comparator Hysteresis V = 0V (Note 1) l 14 35 mV SEL Oscillator Frequency Current Limit not Asserted. See Test Circuit. 120 155 185 kHz Oscillator TC 0.2 %/C DC Maximum Duty Cycle 75 86 95 % t Switch On Time Current Limit not Asserted. 5.6 s ON Output Line Regulation 1.8V < V < 6V l 0.06 0.15 %/V IN V Switch Saturation Voltage I = 700mA l 130 200 mV CESAT SW Switch Leakage Current V = 5V, Switch Off l 0.1 10 A SW Peak Switch Current I Floating (See Typical Application) 0.75 1.0 1.25 A LIM (Internal Trip Point) I Grounded 0.4 A LIM V Shutdown Pin High l 1.8 V SHDNH V Shutdown Pin Low 0.5 V SHDNL V Select Pin High l 1.5 V SELH V Select Pin Low l 0.8 V SELL I Shutdown Pin Bias Current V = 5V l 920 A SHDN SHDN V = 2V l 3 A SHDN V = 0V l 0.1 1 A SHDN I Select Pin Bias Current 0V < V < 5V l 13 A SEL SEL The l denotes specifications which apply over the 0C to 70C Note 1: Hysteresis specified is DC. Output ripple may be higher if temperature range. output capacitance is insufficient or capacitor ESR is excessive. See applications section. 2 U W U U WWW