LTC3403 1.5MHz, 600mA Synchronous Step-Down Regulator with Bypass Transistor

The LTC®3403 is a high efficiency monolithic synchronous buck regulator optimized for WCDMA power amplifier applications. The output voltage can be dynamically programmed from 0.3V to 3.5V. At VOUT > 3.6V an internal bypass P-channel MOSFET connects VOUT directly to VIN, eliminating power loss through the inductor. Selectable forced continuous mode enables fast VOUT response to the controlling input.

Supply current is only 20µA in Burst Mode® operation and drops to <1µA in shutdown. The 2.5V to 5V input voltage range makes the LTC3403 ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems.

Switching frequency is internally set at 1.5MHz, allowing the use of small surface mount inductors and capacitors. The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode.

The LTC3403 is available in a low profile 8-lead 3mm x 3mm DFN package

产品特点 Features

Dynamically Adjustable Output from 0.3V to 3.5V
Very Low Quiescent Current: Only 20µA During Operation
600mA Output Current
Internal P-Channel MOSFET Bypass Transistor
High Efficiency: Up to 96%
1.5MHz Constant Frequency Operation
No Schottky Diode Required
Low Dropout Operation: 100% Duty Cycle
2.5V to 5V Input Voltage Range
Drives Optional External P-Channel MOSFET
Shutdown Mode Draws < 1µA Supply Current
Current Mode Operation for Excellent Line and Load Transient Response
Overtemperature Protected
Available in 8-Lead 3mm x 3mm DFN Package

应用

WCDMA Cell Phone Power Amplifiers
Wireless Modems

典型应用图

参数

LTC3403 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) *
LTC3403EDD	DFN	8	E	$3.00	$2.10
LTC3403EDD#PBF	DFN	8	E	$3.00	$2.10
LTC3403EDD#TR	DFN	8	E		$2.20
LTC3403EDD#TRPBF	DFN	8	E		$2.20

LTC3403 数据手册及相关资料下载

数据手册(英文) : LTC3403 - 1.5MHz, 600mA Synchronous Step-Down Regulator with Bypass Transistor.PDF
应用指南 (英文) : AN118 - High Voltage, Low Noise, DC/DC Converters.PDF
设计要点 (英文) : DN246 - 3MHz Micropower Synchronous Boost Converters Deliver 3W from Two Cells in a Tiny MSOP Package.PDF
设计要点 (中文) : DN246 3MHz Micropower Synchronous Boost Converters Deliver 3W from Two Cells in a Tiny MSOP Package.PDF
可靠性数据 : R415 Reliability Data .PDF