Datasheet LT1307, LT1307B (Analog Devices)

HerstellerAnalog Devices
BeschreibungSingle Cell Micropower 600kHz PWM DC/DC Converters
Seiten / Seite20 / 1 — FEATURES. DESCRIPTIO. A Quiescent Current (LT1307). 1mA Quiescent Current …
Dateiformat / GrößePDF / 383 Kb
DokumentenspracheEnglisch

FEATURES. DESCRIPTIO. A Quiescent Current (LT1307). 1mA Quiescent Current (LT1307B). Operates with V. IN as Low as 1V

Datasheet LT1307, LT1307B Analog Devices

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LT1307/LT1307B Single Cell Micropower 600kHz PWM DC/DC Converters
U FEATURES DESCRIPTIO
■ Uses Small Ceramic Capacitors The LT®1307/LT1307B are micropower, fixed frequency ■
50
µ
A Quiescent Current (LT1307)
DC/DC converters that operate from an input voltage as ■
1mA Quiescent Current (LT1307B)
low as 1V. First in the industry to achieve true current ■
Operates with V
mode PWM performance from a single cell supply, the
IN as Low as 1V
■ 600kHz Fixed Frequency Operation LT1307 features automatic shifting to power saving Burst ■ Starts into Full Load Mode operation at light loads. High efficiency is main- ■ Low Shutdown Current: 3µA tained over a broad 100µA to 100mA load range. The ■
Low-Battery Detector
LT1307B does not shift into Burst Mode operation at light ■ 3.3V at 75mA from a Single Cell loads, eliminating low frequency output ripple at the ■ Automatic Burst Mode® Operation at expense of light load efficiency. The devices contain a low- Light Load (LT1307) battery detector with a 200mV reference and shut down to ■ Continuous Switching at Light Load (LT1307B) less than 5µA. No load quiescent current of the LT1307 is ■ Low V 50 CESAT Switch: 295mV at 500mA µA and the internal NPN power switch handles a 500mA current with a voltage drop of just 295mV.
U
Unlike competitive devices, large electrolytic capacitors
APPLICATIO S
are not required with the LT1307/LT1307B in single cell ■ Pagers applications. The high frequency (600kHz) switching al- ■ Cordless Telephones lows the use of tiny surface mount multilayer ceramic ■ GPS Receivers (MLC) capacitors along with small surface mount induc- ■ Battery Backup tors. The devices work with just 10µF of output capaci- ■ Portable Electronic Equipment tance and require only 1µF of input bypassing. ■ Glucose Meters The LT1307/LT1307B are available in 8-lead MSOP, PDIP ■ Diagnostic Medical Instrumentation and SO packages. , LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation.
U TYPICAL APPLICATIO Single Cell to 3.3V Converter Efficiency
L1 10µH D1 90 C1: MURATA-ERIE GRM235Y5V105Z01 MARCON THCS50E1E105Z VIN SW TOKIN 1E105ZY5U-C103-F C1 3.3V LBI FB C2: MURATA-ERIE GRM235Y5V106Z01 80 1µF 75mA V R1 MARCON THCS50E1E105Z IN = 1.5V LT1307 1.5V SHUTDOWN SHDN LBO 1.02M TOKIN 1E106ZY5U-C304-F CELL 1% VIN = 1V VC GND D1: MOTOROLA MBR0520L C2 70 L1: COILCRAFT D01608C-103 R2 10µF VIN = 1.25V SUMIDA CD43-100 100k 604k MURATA ERIE LQH3C100 EFFICIENCY (%) 1% 680pF FOR 5V OUTPUT: R1 = 1M, R2 = 329k 60 1307 F01 50
Figure 1. Single Cell to 3.3V Boost Converter
0.1 1 10 100 LOAD CURRENT (mA) 1307 TA01 1307fa 1