LT1615/LT1615-1 Micropower Step-Up DC/DC Converters in ThinSOT DESCRIPTIO FEATURES n Low Quiescent Current: The LT 1615/LT1615-1 are micropower step-up DC/DC 20m A in Active Mode converters in a 5-lead low profile (1mm) ThinSOT pack- <1m A in Shutdown Mode age. The LT1615 is designed for higher power systems n Operates with V as Low as 1V with a 350mA current limit and an input voltage range of IN n Low V Switch: 250mV at 300mA 1.2V to 15V, whereas the LT1615-1 is intended for lower CESAT n Uses Small Surface Mount Components power and single-cell applications with a 100mA current n High Output Voltage: Up to 34V limit and an extended input voltage range of 1V to 15V. TM n Low Profile (1mm) ThinSOT Package Otherwise, the two devices are functionally equivalent. Both devices feature a quiescent current of only 20m A at no U load, which further reduces to 0.5m A in shutdown. A APPLICATIO S current limited, fixed off-time control scheme conserves operating current, resulting in high efficiency over a broad n LCD Bias range of load current. The 36V switch allows high voltage n Handheld Computers outputs up to 34V to be easily generated in a simple boost n Battery Backup topology without the use of costly transformers. The n Digital Cameras LT1615s low off-time of 400ns permits the use of tiny, low profile inductors and capacitors to minimize footprint and cost in space-conscious portable applications. , LTC and LT are registered trademarks of Linear Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation. TYPICAL APPLICATIO 1-Cell Li-Ion to 20V Converter for LCD Bias Efficiency 85 L1 D1 10H 80 V 20V IN V = 4.2V 2.5V TO 4.2V 12mA IN 75 R1 V SW IN V = 3.3V IN 2M V = 2.5V 70 IN C2 LT1615 1F 65 SHDN FB GND C1 R2 4.7F 60 130k 55 C1: TAIYO YUDEN LMK316BJ475 1615/-1 TA01 C2: TAIYO YUDEN TMK316BJ105 D1: MOTOROLA MBR0530 50 L1: MURATA LQH3C100K24 0.1 0.3 1 3 10 30 LOAD CURRENT (mA) 1615/-1 TA01a sn16151 16151fas 1 EFFICIENCY (%) U ULT1615/LT1615-1 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) ORDER PART V , SHDN Voltage ................................................... 15V NUMBER IN SW Voltage .............................................................. 36V LT1615ES5 TOP VIEW FB Voltage .................................................................V IN LT1615ES5-1 SW 1 5 V IN Current into FB Pin ................................................. 1mA LT1615IS5 GND 2 Junction Temperature........................................... 125 C LT1615IS5-1 FB 3 4 SHDN Operating Temperature Range (Note 2) .. 40 C to 85 C S5 PACKAGE Storage Temperature Range ................. 65 C to 150 C S5 PART MARKING 5-LEAD PLASTIC SOT-23 Lead Temperature (Soldering, 10 sec).................. 300 C T = 125 C, q = 256 C/W JMAX JA LTIZ LTKH LTXZ LTBHT Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25 C. V = 1.2V, V = 1.2V unless otherwise noted. A IN SHDN PARAMETER CONDITIONS MIN TYP MAX UNITS Minimum Input Voltage LT1615-1 1.0 V LT1615 1.2 V Quiescent Current Not Switching 20 30 m A V = 0V 1 m A SHDN FB Comparator Trip Point l 1.205 1.23 1.255 V FB Comparator Hysteresis 8mV Output Voltage Line Regulation 1.2V < V < 12V 0.05 0.1 %/V IN FB Pin Bias Current (Note 3) V = 1.23V l 30 80 nA FB Switch Off Time V > 1V 400 ns FB V < 0.6V 1.5 m s FB Switch V I = 70mA (LT1615-1) 85 120 mV CESAT SW I = 300mA (LT1615) 250 350 mV SW Switch Current Limit LT1615-1 75 100 125 mA LT1615 300 350 400 mA SHDN Pin Current V = 1.2V 2 3 m A SHDN V = 5V 8 12 m A SHDN SHDN Input Voltage High 0.9 V SHDN Input Voltage Low 0.25 V Switch Leakage Current Switch Off, V = 5V 0.01 5 m A SW Note 1: Absolute Maximum Ratings are those values beyond which the life characterization and correlation with statistical process controls. The of a device may be impaired. LT1615I/LT1615I-1 is guaranteed to meet performance specifications over the 40 C to 85 C operating temperature range. Note 2: The LT1615E and LT1615E-1 are guaranteed to meet performance specifications from 0 C to 70 C. Specifications over the Note 3: Bias current flows into the FB pin. 40 C to 85 C operating temperature range are assured by design, sn16151 16151fas 2 U WWW