RD-128: 5V @ 3A; 6 ~ 42V in, 85%


This LM25576 reference design is based on a LM25576 demonstration board which was a assembled and tested platform to evaluate the LM25576 SIMPLE SWITCHER® stepdown converter. The reference design takes a 6V-42V input and generates a regulated 5V output that can source up to 3A of current.

The primary consideration for this design was to obtain the highest efficiency LM25576 design, over it’s full operating voltage input range.

Cost and size of components were a secondary consideration (i.e.: using small, less expensive ceramic capacitors; a small, off the shelf inductor; etc.). The result is a design that achieves 95% peak efficiency, with a short list of necessary components.

All optional features of the LM25576 can be enabled if necessary. The board layout is ideal for demonstrating the capabilities of the target design, while allowing for easy probing and adjustments.


Manufacturer Texas Instruments
Category AC/DC and DC/DC Conversion
Sub-Category DC/DC SMPS - Single Output
Eval Board Board not Stocked
Topology Step Down
Outputs and Type 1 Non-Isolated
Voltage Out: Factory Set 5 V
Current Out 3 A
Voltage In 6 ~ 42 V
Efficiency @ Conditions >90%, 7V in, 5V @ 500 mA ~ 2 A
>85%, 12V in, 5V @ 0.5 ~ 2.5 A
>82%, 24V in, 5V @ 500 mA ~ 3 A
>78%, 42V in, 5V @ 750 mA ~ 3 A
Voltage Out Range 1.225 ~ Vin
Features Current Limit (Adj. or Fixed)
Short Circuit Protection
Shutdown, Enable, Standby
Soft Start
Thermal Protection
Switching Frequency 300 kHz
Standby Current [Typical] 48 µA
Quiescent Current [Typical] 48 µA
Component Count + Extras 16 + 1
Internal Switch Yes
Design Author Texas Instruments
Application / Target Market Automotive
White Goods
Standby Current [Maximum] 70 µA
Quiescent Current [Maximum] 70 µA
Main I.C. Base Part LM25576
Date Created By Author
Date Added To Library 2011-03