LT1301 Micropower High Efficiency 5V/12V Step-Up DC/DC Converter for Flash Memory DESCRIPTION FEATURES n 12V at 120mA from 5V or 3.3V Supply The LT1301 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 Better High Current Efficiency Than CMOS or 12V from a two-cell battery input. It features program- n Up to 89% Efficiency mable 5V or 12V 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 5V or 12V Output has a low 170mV saturation voltage at a switch current of n Low V Switch: 170mV at 1A Typical 1A, a four-fold reduction over prior designs. A 155kHz CESAT n I Pin Programs Peak Switch Current internal oscillator allows the use of extremely small sur- LIM 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 for soft start or to program peak switch current n with a single resistor allowing the use of even smaller Flash Memory V Generator PP n inductors in lighter load applications. The LT1301 is Palmtop Computers n available in an 8-lead SOIC package, minimizing board Portable Instruments n space requirements. For a selectable 3.3V/5V step-up Bar-Code Scanners n converter, please see the LT1300. For higher output Personal Digital Assistants n power, see the LT1302. PCMCIA Cards Burst Mode is a trademark of Linear Technology Corporation. TYPICAL APPLICATIONS N L1 Output Voltage Efficiency D1 5V 33H 12V OR 90 OUTPUT 3.3V 12V 88 V = 5V IN V SW IN V OUT 86 SELECT SENSE 2V/DIV V = 3.3V IN + 84 C1 LT1301 47F + C2 82 33F 0.1F* 20V SHUTDOWN SHDN I N/C 80 LIM PGND GND 78 SHUTDOWN 10V/DIV 76 1ms/DIV 74 LT1301 TAO1 *REQUIRED FOR 5V OUTPUT V = 5V, V = 12V IN OUT LT1301 F1 72 LOAD = 100 L1 = COILCRAFT DO3316-333 OR SUMIDA CD73-330KC 0 1 10 100 300 D1 = 1N5817 OR MOTOROLA MBRS130LT3 LOAD CURRENT (mA) C1 = AVX TPSD476M016R0100 LT1301 TA2 OR SANYO OS-CON 165A47M C2 = AVX TPSD336M020R0100 OR SANYO OS-CON 205A33M LT1300 F2 Figure 1. 3.3V/5V to 12V Step-Up Converter 1 EFFICIENCY (%) U ULT1301 ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER INFORMATION V Voltage .............................................................. 10V IN ORDER PART TOP VIEW SW1 Voltage ............................................................ 20V NUMBER GND 1 8 PGND Sense Voltage .......................................................... 20V SEL 2 SW LT1301CN8 7 Shutdown Voltage ................................................... 10V LT1301CS8 SHDN 3 6 V IN Select Voltage .......................................................... 10V LT1301IS8 SENSE I 4 5 LIM I Voltage ............................................................ 0.5V LIM Maximum Power Dissipation ............................. 500mW N8 PACKAGE S8 PACKAGE S8 PART MARKING 8-LEAD PLASTIC DIP 8-LEAD PLASTIC SOIC Operating Temperature Range LT1301C ................................................... 0C to 70C T = 100C, = 150C/ W 1301 JMAX JA LT1301I .................................................. 40C to 85C 1301I Storage Temperature Range ................. 65C to 150C Lead Temperature (Soldering, 10 sec).................. 300C 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 11.52 12.00 12.48 V OUT SEL V = 0V l 4.75 5.00 5.25 V SEL Output Referred V = 5V (Note 1) l 50 100 mV SEL Comparator Hysteresis V = 0V (Note 1) l 22 50 mV SEL Oscillator Frequency Current Limit not Asserted. 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 820 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 Note 1: Hysteresis specified is DC. Output ripple may be higher if The l denotes specifications which apply over the 0C to 70C temperature range. output capacitance is insufficient or capacitor ESR is excessive. See operation section. 2 U W U U WWW