LTC3440 Micropower Synchronous Buck-Boost DC/DC Converter

The LTC®3440 is a high efficiency, fixed frequency, Buck-Boost DC/DC converter that operates from input voltages above, below or equal to the output voltage. The topology incorporated in the IC provides a continuous transfer function through all operating modes, making the product ideal for single lithium-ion, multicell alkaline or NiMH applications where the output voltage is within the battery voltage range.

The device includes two 0.19Ohm N-channel MOSFET switches and two 0.22Ohm P-channel switches. Switching frequencies up to 2MHz are programmed with an external resistor and the oscillator can be synchronized to an external clock. Quiescent current is only 25µA in Burst Mode operation, maximizing battery life in portable applications. Burst Mode operation is user controlled and can be enabled by driving the MODE/SYNC pin high. If the MODE/SYNC pin has either a clock or is driven low, then fixed frequency switching is enabled.

Other features include a 1µA shutdown, soft-start control, thermal shutdown and current limit. The LTC3440 is available in the 10-pin thermally enhanced MSOP package.

Protected by U.S. Patents including 6404251, 6166527

产品特点 Features

Single Inductor
Fixed Frequency Operation with Battery Voltages
Above, Below or Equal to the Output
Synchronous Rectification: Up to 96% Efficiency
25µA Quiescent Current in Burst Mode® Operation
Up to 600mA Continuous Output Current
No Schottky Diodes Required (VOUT < 4.3V)
VOUT Disconnected from VIN During Shutdown
2.5V to 5.5V Input and Output Range
Programmable Oscillator Frequency from 300kHz to 2MHz
Synchronizable Oscillator
Burst Mode Enable Control
<1µA Shutdown Current
Small Thermally Enhanced 10-Pin MSOP and (3mm × 3mm) DFN Packages

应用

Palmtop Computers
Handheld Instruments
MP3 Players
Digital Cameras

典型应用图

参数

LTC3440 订购信息和价格参考Package Variations and Pricing

器件型号	封装	引脚	温度	价格 (以 1 ~ 99 片为批量)	价格 (以 1000 片为批量) *
LTC3440EDD	DFN	10	E	$3.38	$2.84
LTC3440EDD#PBF	DFN	10	E	$3.38	$2.84
LTC3440EDD#TR	DFN	10	E		$2.94
LTC3440EDD#TRPBF	DFN	10	E		$2.94
LTC3440EMS	MSOP	10	E	$3.24	$2.74
LTC3440EMS#PBF	MSOP	10	E	$3.24	$2.74
LTC3440EMS#TR	MSOP	10	E		$2.80
LTC3440EMS#TRPBF	MSOP	10	E		$2.80

LTC3440 数据手册及相关资料下载

数据手册(英文) : LTC3440 - Micropower Synchronous Buck-Boost DC/DC Converter.PDF
设计要点 (英文) : Design Solutions 10 - Active Voltage Positioning Reduces Output Capacitors.PDF
可靠性数据 : R415 Reliability Data .PDF