LTC3547B - Dual Monolithic 300mA Synchronous Step-Down Regulator

The input voltage range is 2.5V to 5.5V, making it ideal for Li-Ion polymer and USB powered applications. Supply current is only 1µA in shutdown.

An internally set 2.25MHz switching frequency allows the use of tiny surface mount inductors and capacitors. Internal soft-start reduces inrush current during start-up. All outputs are internally compensated to work with ceramic capacitors. The LTC3547B is available in a low proﬁle (0.75mm) 3mm × 2mm DFN package. The LTC3547B is also available in a fixed output voltage configuration selected via internal resistor dividers.

Features

High Efficiency (Up to 96%) Dual Step-Down Outputs
300mA Output Current per Channel at VIN = 3V
2.25MHz Constant-Frequency Operation
2.5V to 5.5V Input Voltage Range
Low Dropout Operation: 100% Duty Cycle
No Schottky Diodes Required
Internally Compensated for All Ceramic Capacitors
Independent Internal Soft-Start for Each Channel
Available in Fixed Output Versions
Current Mode Operation for Excellent Line and Load Transient Response
0.6V Reference Allows Low Output Voltages
Short-Circuit Protected
Ultralow Shutdown Current: IQ < 1µA
Low Profile (0.75mm) 8-Lead 3mm × 2mm DFN Package

Typical Application

Applications

Cellular Telephones
Digital Still Cameras
Wireless and DSL Modems
Portable Media Players
PDAs/Palmtop PCs

Packaging

Order Information

Part Number	Package	Temp	Price(1-99)	Price (1k)*
LTC3547BEDDB-1#PBF	3x2 DFN-8	E	$2.79
LTC3547BEDDB-1#TRMPBF	3x2 DFN-8	E	$2.79	$2.00
LTC3547BEDDB-1#TRPBF	3x2 DFN-8	E	$2.79	$1.95
LTC3547BEDDB#PBF	3x2 DFN-8	E	$2.79
LTC3547BEDDB#TRMPBF	3x2 DFN-8	E	$2.79	$2.00
LTC3547BEDDB#TRPBF	3x2 DFN-8	E	$2.79	$1.95
LTC3547BIDDB#PBF	3x2 DFN-8	I	$3.34
LTC3547BIDDB#TRMPBF	3x2 DFN-8	I	$3.34	$2.39
LTC3547BIDDB#TRPBF	3x2 DFN-8	I	$3.34	$2.34