LT1934/LT1934-1 Micropower Step-Down Switching Regulators in ThinSOT and DFN FEATURES DESCRIPTION n Wide Input Voltage Range: 3.2V to 34V The LT 1934 is a micropower step-down DC/DC converter n Micropower Operation: I = 12A with internal 400mA power switch, packaged in a low Q n 5V at 250mA from 6.5V to 34V Input (LT1934) pro le (1mm) ThinSOT. With its wide input range of 3.2V n 5V at 60mA from 6.5V to 34V Input (LT1934-1) to 34V, the LT1934 can regulate a wide variety of power n 3.3V at 250mA from 4.5V to 34V Input (LT1934) sources, from 4-cell alkaline batteries and 5V logic rails n 3.3V at 60mA from 4.5V to 34V Input (LT1934-1) to unregulated wall transformers and lead-acid batteries. n Low Shutdown Current: <1A Quiescent current is just 12A and a zero current shut- n Low V Switch: 200mV at 300mA down mode disconnects the load from the input source, CESAT n Low Pro le (1mm) SOT-23 (ThinSOT) and simplifying power management in battery-powered sys- (2mm 3mm 0.8mm) 6-Pin DFN Package tems. Burst Mode operation and the low drop internal power switch result in high ef ciency over a broad range of load current. APPLICATIONS The LT1934 provides up to 300mA of output current. The n Wall Transformer Regulation LT1934-1 has a lower current limit, allowing optimum n Automotive Battery Regulation choice of external components when the required output n Standby Power for Portable Products current is less than 60mA. Fast current limiting protects n Distributed Supply Regulation the LT1934 and external components against shorted n Industrial Control Supplies outputs, even at 34V input. L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION 3.3V Step-Down Converter Ef ciency 100 D2 LT1934 V = 12V IN 90 0.22F L1 BOOST V = 5V 47H OUT V OUT V IN V SW 3.3V IN 4.5V TO 34V 80 250mA C2 V = 3.3V D1 OUT 2.2F LT1934 10pF 1M + 70 C1 ON OFF SHDN FB 100F 604k GND 60 50 C1: SANYO 4TPB100M 1934 TA01 0.1 1 10 100 C2: TAIYO YUDEN GMK325BJ225MN D1: ON SEMICONDUCTOR MBR0540 LOAD CURRENT (mA) D2: CENTRAL CMDSH-3 1934 TA02 L1: SUMIDA CDRH4D28-470 1934fe 1 EFFICIENCY (%)LT1934/LT1934-1 ABSOLUTE MAXIMUM RATINGS (Note 1) Input Voltage (V ) ................................................... 34V Operating Temperature Range (Note 2) IN BOOST Pin Voltage ................................................. 40V LT1934E/LT1934E-1 .............................40C to 85C BOOST Pin Above SW Pin ........................................ 20V LT1934I/LT1934I-1 .............................40C to 125C SHDN Pin ................................................................. 34V Maximum Junction Temperature .......................... 125C FB Voltage .................................................................. 6V Storage Temperature Range ...................65C to 150C SW Voltage ............................................................... V Lead Temperature (Soldering, 10 sec) IN TSOT-23 ............................................................300C PIN CONFIGURATION TOP VIEW TOP VIEW BOOST 1 6 FB BOOST 1 6 SW 7 SW 2 5 GND GND 2 5 V IN V 3 4 SHDN FB 3 4SHDN IN S6 PACKAGE DCB PACKAGE 6-LEAD PLASTIC TSOT-23 6-LEAD (2mm s 3mm) PLASTIC DFN T = 125C, = 250C/ W, = 102C/W JMAX JA JC = 73.5C/ W, = 12C/W JA JC EXPOSED PAD (PIN 7) IS GND, MUST BE SOLDEDED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL S6 PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT1934ES6 PBF LT1934ES6 TRPBF LTXP 6-Lead Plastic TSOT-23 40C to 85C LT1934ES6-1 PBF LT1934ES6-1 TRPBF LTF8 6-Lead Plastic TSOT-23 40C to 85C LT1934IS6 PBF LT1934IS6 TRPBF LTAJB 6-Lead Plastic TSOT-23 40C to 125C LT1934IS6-1 PBF LT1934IS6-1 TRPBF LTAJC 6-Lead Plastic TSOT-23 40C to 125C LT1934IDCB PBF LT1934IDCB TRPBF LCFZ 6-Lead (2mm 3mm) Plastic DFN 40C to 125C LT1934EDCB PBF LT1934EDCB TRPBF LCFZ 6-Lead (2mm 3mm) Plastic DFN 40C to 85C LT1934IDCB-1 PBF LT1934IDCB-1 TRPBF LDHC 6-Lead (2mm 3mm) Plastic DFN 40C to 125C LT1934EDCB-1 PBF LT1934EDCB-1 TRPBF LDHC 6-Lead (2mm 3mm) Plastic DFN 40C to 85C LEAD BASED FINISH TAPE AND REEL S6 PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT1934ES6 LT1934ES6 TR LTXP 6-Lead Plastic TSOT-23 40C to 85C LT1934ES6-1 LT1934ES6-1 TR LTF8 6-Lead Plastic TSOT-23 40C to 85C LT1934IS6 LT1934IS6 TR LTAJB 6-Lead Plastic TSOT-23 40C to 125C LT1934IS6-1 LT1934IS6-1 TR LTAJC 6-Lead Plastic TSOT-23 40C to 125C LT1934IDCB LT1934IDCB TR LCFZ 6-Lead (2mm 3mm) Plastic DFN 40C to 125C LT1934EDCB LT1934EDCB TR LCFZ 6-Lead (2mm 3mm) Plastic DFN 40C to 85C LT1934IDCB-1 LT1934IDCB-1 TR LDHC 6-Lead (2mm 3mm) Plastic DFN 40C to 125C LT1934EDCB-1 LT1934EDCB-1 TR LDHC 6-Lead (2mm 3mm) Plastic DFN 40C to 85C Consult LTC Marketing for parts speci ed with wider operating temperature ranges. *The temperature grade is identi ed by a label on the shipping container. 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