LTC3541 High Efficiency Buck + VLDO Regulator

The LTC3541 combines a synchronous buck DC/DC converter with a very low dropout linear regulator (VLDO) to provide up to two output voltages from a single input voltage with minimal external components. When configured for dual output operation, the LTC3541’s auto start-up feature will bring the Buck output into regulation in a controlled manner prior to enabling the VLDO regulator output without the need for external pin control. VLDO/ linear regulator output prior to Buck output sequencing may also be obtained via external pin control. The input voltage range is ideally suited for Li-Ion battery-powered applications, as well as powering sub-3.3V logic from 5V or 3.3V rails.

The synchronous buck converter provides a high efficiency output, typically 90%, capable of providing up to 500mA of continuous output current while switching at 2.25MHz, allowing the use of small surface mount inductors and capacitors. A mode-select pin allows Burst Mode operation to be enabled for higher effi ciency at light load currents, or disabled for lower noise, constant frequency operation.

The VLDO regulator provides a low noise, low voltage output capable of providing up to 300mA of continuous output current using only a 2.2μF ceramic capacitor. The input supply voltage of the VLDO regulator (LVIN) may come from the buck regulator or a separate supply.

产品特点 Features

High Efficiency, 500mA Buck Plus 300mA VLDO Regulator
Auto Start-Up Powers Buck Output Prior to VLDO/linear Regulator Output
Independent High Efficiency, 500mA Buck (VIN: 2.7V to 5.5V)
300mA VLDO Regulator with 30mA Standalone Mode
No External Schottky Diodes Required
Buck Output Voltage Range: 0.8V to 5V
VLDO Input Voltage Range (LVIN): 0.9V to 5.5V
VLDO Output Voltage Range VLDO: 0.4V to 4.1V
Selectable Fixed Frequency, Pulse-Skip Operation or Burst Mode® Operation
Short-Circuit Protected
Current Mode Operation for Excellent Line and Load
Transient Response
Constant Frequency Operation: 2.25MHz
Low Dropout Buck Operation: 100% Duty Cycle
Small, Thermally Enhanced, 10-Lead (3mm × 3mm) DFN Package

应用

PDAs/Palmtop PCs
Digital Cameras
Cellular Phones
PC Cards
Wireless and DSL Modems
Other Portable Power Systems

典型应用图

参数

LTC3541 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) *
LTC3541EDD#PBF	DFN	10	E	$2.70	$1.89
LTC3541EDD#TRPBF	DFN	10	E		$1.95
LTC3541EDD-1#PBF	DFN	10	E	$2.70	$1.89
LTC3541EDD-1#TRPBF	DFN	10	E		$1.95
LTC3541EDD-2#PBF	DFN	10	E	$2.70	$1.89
LTC3541EDD-2#TRPBF	DFN	10	E		$1.95
LTC3541EDD-3#PBF	DFN	10	E	$2.70	$1.89
LTC3541EDD-3#TRPBF	DFN	10	E		$1.95

LTC3541 数据手册及相关资料下载

数据手册(英文) : LTC3541 - High Efficiency Buck + VLDO Regulator.PDF
产品选型卡 : Energy Harvesting Portfolio.PDF
可靠性数据 : R415 Reliability Data .PDF