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1615/LT1615-1 are micropower step-up DC/DC converters in a 5-lead low profile (1mm) ThinSOT pack- age. The LT1615 is designed for higher power systems with a 350mA current limit and an input voltage range of 1.2V to 15V, whereas the LT1615-1 is intended for lower power and single-cell applications with a 100mA current limit and an extended input voltage range of 1V to 15V. Otherwise, the two devices are functionally equivalent. Both devices feature a quiescent current of only 20mA at no load, which further reduces to 0.5 mA in shutdown. A current limited, fixed off-time control scheme conserves operating current, resulting in high efficiency over a broad range of load current. The 36V switch allows high voltage outputs up to 34V to be easily generated in a simple boost topology without the use of costly transformers. The LT1615’s 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. n Low Quiescent Current: 20mA in Active Mode <1mA in Shutdown Mode n Operates with VIN as Low as 1V n Low VCESAT Switch: 250mV at 300mA n Uses Small Surface Mount Components n High Output Voltage: Up to 34V n Low Profile (1mm) ThinSOT TM Package n LCD Bias n Handheld Computers n Battery Backup n Digital Cameras , LTC and LT are registered trademarks of Linear Technology Corporation. 1-Cell Li-Ion to 20V Converter for LCD Bias VIN SW FB LT1615 VIN 2.5V TO 4.2V 10µH D1 SHDN 130k 1µF 20V 12mA C1: TAIYO YUDEN LMK316BJ475 C2: TAIYO YUDEN TMK316BJ105 D1: MOTOROLA MBR0530 L1: MURATA LQH3C100K24 1615/-1 TA01 GNDC1 4.7µF Efficiency LOAD CURRENT (mA) 0.1 0.3 EFFICIENCY (%) 1 3 10 30 1615/-1 TA01a VIN = 4.2V VIN = 2.5V VIN = 3.3V APPLICATIO SU

FEATURES

ThinSOT is a trademark of Linear Technology Corporation.

ABSOLUTE AXI U RATI GSW WW U PACKAGE/ORDER I FOR ATIOUU W (Note 1) Operating Temperature Range (Note 2) .. – 40°C to 85°C ORDER PART NUMBER LT1615ES5 LT1615ES5-1 LT1615IS5 LT1615IS5-1 S5 PART MARKING SW 1 GND 2 TOP VIEW S5 PACKAGE 5-LEAD PLASTIC SOT-23 FB 3

5 VIN

4 SHDN

ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating PARAMETER CONDITIONS MIN TYP MAX UNITS Minimum Input Voltage LT1615-1 1.0 V LT1615 1.2 V Quiescent Current Not Switching 20 30 mA VSHDN = 0V 1 mA FB Comparator Trip Point l 1.205 1.23 1.255 V FB Comparator Hysteresis 8m V Output Voltage Line Regulation 1.2V < V IN < 12V 0.05 0.1 %/V FB Pin Bias Current (Note 3) V FB = 1.23V l 30 80 nA Switch Off Time V FB > 1V 400 ns VFB < 0.6V 1.5 ms Switch VCESAT ISW = 70mA (LT1615-1) 85 120 mV ISW = 300mA (LT1615) 250 350 mV Switch Current Limit LT1615-1 75 100 125 mA LT1615 300 350 400 mA SHDN Pin Current V SHDN = 1.2V 2 3 mA VSHDN = 5V 8 12 mA SHDN Input Voltage High 0.9 V SHDN Input Voltage Low 0.25 V Switch Leakage Current Switch Off, V SW = 5V 0.01 5 mA Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LT1615E and LT1615E-1 are guaranteed to meet performance specifications from 0°C to 70°C. Specifications over the –40 °C to 85°C operating temperature range are assured by design, TJMAX = 125°C, qJA = 256°C/W temperature range, otherwise specifications are at TA = 25°C. VIN = 1.2V, VSHDN = 1.2V unless otherwise noted. LTIZ LTKH LTXZ LTBHT characterization and correlation with statistical process controls. The LT1615I/LT1615I-1 is guaranteed to meet performance specifications over the –40°C to 85°C operating temperature range. Note 3: Bias current flows into the FB pin. Consult LTC Marketing for parts specified with wider operating temperature ranges.

TYPICAL PERFOR A CE CHARACTERISTICSUW Switch Saturation Voltage (VCESAT) Quiescent Current Feedback Pin Voltage and Bias Current TEMPERATURE (°C) –50 –25 0 25 50 75 100 SWITCH VOLTAGE (V) 1615/-1 G01 0.60 0.55 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 ISWITCH = 500mA ISWITCH = 300mA TEMPERATURE (°C) –50 FEEDBACK VOLTAGE (V) 1615/-1 G02 1.25 1.24 1.23 1.22 1.21 1.20 BIAS CURRENT (nA) CURRENT VOLTAGE –25 0 25 50 75 100 TEMPERATURE (°C) QUIESCENT CURRENT (µA) 1615/-1 G03 –50 –25 0 25 50 75 100 VIN = 12V VIN = 1.2V VFB = 1.23V NOT SWITCHING PI FU CTIO S UU U SW (Pin 1): Switch Pin. This is the collector of the internal NPN power switch. Minimize the metal trace area con- nected to this pin to minimize EMI. GND (Pin 2): Ground. Tie this pin directly to the local ground plane. FB (Pin 3): Feedback Pin. Set the output voltage by selecting values for R1 and R2 (see Figure 1): RR VOUT12 12 3 1=- æ Łç ö ł÷. SHDN (Pin 4): Shutdown Pin. Tie this pin to 0.9V or higher to enable the device. Tie below 0.25V to turn off the device. VIN (Pin 5): Input Supply Pin. Bypass this pin with a capacitor as close to the device as possible. TEMPERATURE (°C) SWITCH OFF TIME (ns) 1615/-1 G04 550 500 450 400 350 300 250 –50 –25 0 25 50 75 100 VIN = 1.2V VIN = 12V TEMPERATURE (°C) PEAK CURRENT (mA) 1615/-1 G05 400 350 300 250 200 150 100 –50 –25 0 25 50 75 100 VIN = 12V VIN = 1.2V VIN = 12V LT1615-1 LT1615 VIN = 1.2V SHUTDOWN PIN VOLTAGE (V) SHUTDOWN PIN CURRENT (µA) 1615/-1 G03 0 5 10 15 25°C 100°C Switch Off Time Shutdown Pin Current Switch Current Limit

Figure 1. LT1615 Block Diagram shot, again allowing L1 to deliver current to the output.

correct inductance value for your design. Table 1. Recommended Inductors performance. Pick a standard inductor close to this value. used (see Current Limit Overshoot section). without excessive reduction in maximum output current. value to be used for a SEPIC regulator using the LT1615. by the inductor (and the diode) during normal operation.

be used at the output to minimize the output ripple voltage. a capacitor with a sufficient voltage rating. inductor current, then delivering that current to the load. Table 2. Recommended Capacitors

2-Cell to 3.3V Boost Converter VIN SW FB LT1615 VIN 1.5V TO 3V 4.7µH D1 SHDN 604k 22µF 3.3V 60mA 1615/-1 TA03 GNDC1 4.7µF C1: TAIYO YUDEN LMK316BJ475 (408) 573-4150 C2: TAIYO YUDEN JMK325BJ226 (408) 573-4150 L1: MURATA LQH3C4R7M24 (814) 237-1431 D1: MOTOROLA MBR0520 (800) 441-2447 4.7pF LOAD CURRENT (mA) 0.1 EFFICIENCY (%) 1 10 100 1615/-1 TA03a VIN = 3V VIN = 1.5V 2-Cell to 3.3V Converter Efficiency 1-Cell to 3.3V Boost Converter 4-Cell to 5V SEPIC Converter VIN SW FB LT1615 VIN 3V TO 6V 10µH D1 1µF SHDN 324k 10µF 40mA 1615/-1 TA07 GNDC1 4.7µF C1: TAIYO YUDEN LMK316BJ475 (408) 573-4150 C2: TAIYO YUDEN JMK316BJ106 (408) 573-4150 C3: TAIYO YUDEN JMK107BJ105 (408) 573-4150 L1, L2: MURATA LQH3C100K24 (814) 237-1431 D1: MOTOROLA MBR0520 (800) 441-2447 10µH 4.7pF 1-Cell Li-Ion to 3.3V SEPIC Converter VIN SW FB LT1615 VIN 2.5V TO 4.2V 10µH D1 1µF SHDN 604k 10µF 3.3V 50mA 1615/-1 TA07 GNDC1 4.7µF C1: TAIYO YUDEN LMK316BJ475 (408) 573-4150 C2: TAIYO YUDEN JMK316BJ106 (408) 573-4150 C3: TAIYO YUDEN JMK107BJ105 (408) 573-4150 L1, L2: MURATA LQH3C100K24 (814) 237-1431 D1: MOTOROLA MBR0520 (800) 441-2447 10µH 4.7pF Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. VIN SW FB LT1615-1 VIN 1V TO 1.5V 22µH D1 SHDN 604k 10µF 3.3V 15mA 1615/-1 TA04 GNDC1 4.7µF C1: TAIYO YUDEN LMK316BJ475 (408) 573-4150 C2: TAIYO YUDEN JMK316BJ106 (408) 573-4150 L1: MURATA LQH3C220K24 (814) 237-1431 D1: CENTRAL SEMICONDUCTOR CMDSH-3 (516) 435-1110 4.7pF PIN Diode Driver VIN SW FB LT1615-1 VIN 1V TO 6V 22µH D1 SHDN 365k 10M 1µF 35V 500µA 1615/-1 TA09 GNDC1 4.7µF C1: TAIYO YUDEN EMK316BJ475 (408) 573-4150 C2: TAIYO YUDEN GMK316BJ105 (408) 573-4150 L1: MURATA LQH3C220K24 (814) 237-1431 D1: MOTOROLA MBR0540 (800) 441-2447

Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 l FAX: (408) 434-0507 l www.linear-tech.com ª LINEAR TECHNOLOGY CORPORA TION 1 998 16151fa LT/TP 0601 1.5K REV A • PRINTED IN USA RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1307 Single-Cell Micropower 600kHz PWM DC/DC Converter 3.3V at 75mA from One Cell, MSOP Package LT1316 Burst Mode TM Operation DC/DC with Programmable Current Limit 1.5V Minimum, Precise Control of Peak Current Limit LT1317 2-Cell Micropower DC/DC with Low-Battery Detector 3.3V at 200mA from Two Cells, 600kHz Fixed Frequency LT1610 Single-Cell Micropower DC/DC Converter 3V at 30mA from 1V, 1.7MHz Fixed Frequency LT1611 1.4MHz Inverting Switching Regulator in 5-Lead ThinSOT –5V at 150mA from 5V Input, Tiny ThinSOT Package LT1613 1.4MHz Switching Regulator in 5-Lead ThinSOT 5V at 200mA from 3.3V Input, Tiny ThinSOT Package LT1617 Micropower Inverting DC/DC Converter in 5-Lead ThinSOT –15V at 12mA from 2.5V Input, Tiny ThinSOT Package Burst Mode is a trademark of Linear Technology Corporation PACKAGE DESCRIPTIO U TYPICAL APPLICATIO SU VIN SW FB LT1615 VIN 1.5V TO 5V 10µH D1 SHDN 130k 1µF 20V 4mA –20V 4mA 1615/-1 TA05 GND 1µF 4.7µF C1: TAIYO YUDEN LMK316BJ475 (408) 573-4150 C2, C3, C4: TAIYO YUDEN TMK316BJ105 (408) 573-4150 C5: TAIYO YUDEN LMK212BJ105 (408) 573-4150 L1: MURATA LQH3C100K24 (814) 237-1431 D1, D2, D3, D4: MOTOROLA MBR0530 (800) 441-2447 4.7pF 1µF C5 1µF –20V Dual Output Converter with Output Disconnect 5-Lead Plastic SOT-23 (Reference LTC DWG # 05-08-1633) (Reference LTC DWG # 05-08-1635) L DATUM ‘A’ .09 – .20 (.004 – .008) (NOTE 2) S5 SOT-23 0401 1.50 – 1.75 (.059 – .069) (NOTE 3) 2.60 – 3.00 (.102 – .118) .25 – .50 (.010 – .020) (5PLCS, NOTE 2) PIN ONE 2.80 – 3.10 (.110 – .118) (NOTE 3) .95 (.037) REF A A2 1.90 (.074) REF .20 (.008) MILLIMETERS (INCHES) NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS 2. DIMENSIONS ARE IN 3. DRAWING NOT TO SCALE 4. DIMENSIONS ARE INCLUSIVE OF PLATING 5. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 6. MOLD FLASH SHALL NOT EXCEED .254mm 7. PACKAGE EIAJ REFERENCE IS: SC-74A (EIAJ) FOR ORIGINAL JEDEL MO-193 FOR THIN .90 – 1.45 (.035 – .057) SOT-23 (Original) .00 – .15 (.00 – .006) .90 – 1.30 (.035 – .051) .35 – .55 (.014 – .021)

1.00 MAX

(.039 MAX) SOT-23 (ThinSOT) A L .01 – .10 (.0004 – .004) .80 – .90 (.031 – .035) .30 – .50 REF (.012 – .019 REF)