LT1615/LT1615-1 Micropower Step-Up DC/DC Converters in ThinSOT UFEATURESDESCRIPTIO ■ Low Quiescent Current: The LT®1615/LT1615-1 are micropower step-up DC/DC 20 µ A in Active Mode converters in a 5-lead low profile (1mm) ThinSOT pack- <1 µ A in Shutdown Mode age. The LT1615 is designed for higher power systems ■ Operates with V with a 350mA current limit and an input voltage range of IN as Low as 1V ■ Low V 1.2V to 15V, whereas the LT1615-1 is intended for lower CESAT Switch: 250mV at 300mA ■ Uses Small Surface Mount Components power and single-cell applications with a 100mA current ■ High Output Voltage: Up to 34V limit and an extended input voltage range of 1V to 15V. ■ Low Profile (1mm) ThinSOTTM Package Otherwise, the two devices are functionally equivalent. Both devices feature a quiescent current of only 20µA at no U load, which further reduces to 0.5µA in shutdown. A APPLICATIO S current limited, fixed off-time control scheme conserves ■ operating current, resulting in high efficiency over a broad LCD Bias range of load current. The 36V switch allows high voltage ■ Handheld Computers ■ outputs up to 34V to be easily generated in a simple boost Battery Backup ■ topology without the use of costly transformers. The Digital Cameras 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. , LTC and LT are registered trademarks of Linear Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation. UTYPICAL APPLICATIO1-Cell Li-Ion to 20V Converter for LCD BiasEfficiency 85 L1 D1 10µH VIN 20V 80 2.5V TO 4.2V 12mA VIN = 4.2V 75 V R1 IN SW V 2M IN = 3.3V 70 VIN = 2.5V LT1615 C2 1µF SHDN FB 65 C1 GND R2 EFFICIENCY (%) 4.7µF 130k 60 C1: TAIYO YUDEN LMK316BJ475 55 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
