LTC3700 Constant Frequency Step-Down DC/DC Controller with LDO Regulator

The LTC®3700 is a constant frequency current mode stepdown (buck) DC/DC controller with excellent AC and DC load and line regulation. The on-chip 150mA low dropout (LDO) linear regulator can be powered from the buck controller’s input supply, its own independent input supply or the buck regulator’s output. The buck controller incorporates an undervoltage lockout feature that shuts down the controller when the input voltage falls below 2.1V.

The buck regulator provides a ±2.5% output voltage accuracy. It consumes only 210µA of quiescent current in normal operation with the LDO consuming an additional 50µA. In shutdown, a mere 10µA (combined) is consumed.

For applications where efficiency is a prime consideration, the buck controller is configured for Burst Mode operation which enhances efficiency at low output current. To further maximize the life of a battery source, the external P-channel MOSFET is turned on continuously in dropout (100% duty cycle). High constant operating frequency of 550kHz allows the use of a small external inductor.

The LDO is protected by both current limit and thermal shutdown circuits.

The LTC3700 is available in a tiny 10-pin MSOP

产品特点 Features

Dual Output Regulator in Tiny 10-Pin MSOP
High Efficiency: Up to 94%
Wide VIN Range: 2.65V to 9.8V
Constant Frequency 550kHz Operation
150mA LDO Regulator with Current Limit and Thermal Shutdown Protection
High Output Currents Easily Achieved
Burst Mode® Operation at Light Load
Low Dropout: 100% Duty Cycle
Current Mode Operation for Excellent Line and Load Transient Response
0.8V Reference Allows Low Output Voltages
Low Quiescent Current: 260µA Total
Shutdown Mode Draws Only 10µA Supply Current
Common Power Good Output for Both Supplies

应用

Notebook Computers
Portable Instruments
One or Two Li-Ion Battery-Powered Applications

典型应用图

参数

LTC3700 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) *
LTC3700EMS	MSOP	10	E	$3.30	$2.35
LTC3700EMS#PBF	MSOP	10	E	$3.30	$2.35
LTC3700EMS#TR	MSOP	10	E		$2.41
LTC3700EMS#TRPBF	MSOP	10	E		$2.41

LTC3700 数据手册及相关资料下载

数据手册(英文) : LTC3700 - Constant Frequency Step-Down DC/DC Controller with LDO Regulator.PDF
可靠性数据 : R540 Reliability Data .PDF