DC1341A: 5V @ 3A, 4.5 ~ 36V in, SEPIC

Summary

Demonstration circuit 1341A features LT3757EDD in a 300kHz SEPIC converter circuit, designed for 5V output from a 4.5V to 36V input.

The LT3757EDD operates over an input range of 2.9V to 40V, suitable for applications from single-cell lithium-ion battery portable electronics up to high voltage automotive and industrial power supplies. It also exhibits low shutdown quiescent current of 1µA, making them an ideal fit for battery-operated systems. The IC integrates a high voltage, low dropout linear (LDO) regulator. Thanks to a novel FBX pin architecture, the LT3757EDD can be connected directly to a divider from either the positive output or the negative output to ground. They also pack many popular features such as soft-start, input undervoltage lockout, adjustable frequency and synchronization in a small 10-lead MSOP package or a 3mm × 3mm QFN package.

The LT3757EDD datasheet gives a complete description of the part, operation and application information. The datasheet must be read in conjunction with this quick start guide for demo circuit 1341A.

Specifications

Manufacturer	Analog Devices Inc.
Category	AC/DC and DC/DC Conversion
Sub-Category	DC/DC SMPS - Single Output
Eval Board Part Number	DC1341A-ND
Eval Board Supplier	Analog Devices Inc.
Eval Board	Board not Stocked
Topology	Step Up/Down
Outputs and Type	1 Non-Isolated
Voltage Out: Factory Set	5 V
Current Out	3 A
Voltage In	4.5 ~ 36 V
Efficiency @ Conditions	>80%, 8V in, 12V @ 0.03 ~ 2 A >80%, 16V in, 12V @ 0.12 ~ 2 A
Voltage Out Range	- Not Given
Features	Current Limit (Adj. or Fixed) LDO Regulator(s), On-Chip Shutdown, Enable, Standby Soft Start Synchronizable Under Voltage Protection, Brown-Out
Switching Frequency	300 kHz
Standby Current [Typical]	100 nA
Quiescent Current [Typical]	1.6 mA
Component Count + Extras	24 + 7
Internal Switch	No
Design Author	Linear Technology
Application / Target Market	Automotive Portable Devices Power: Industrial Power Telecom
Standby Current [Maximum]	1 µA
Quiescent Current [Maximum]	2.2 mA
Main I.C. Base Part	LT3757
Date Created By Author	2007-10
Date Added To Library	2015-08