UCC28950EVM-442(#2): 12V @ 50A, 390VDC in

Summary

This 600-W EVM was designed to demonstrate how the UCC28950 control device could be used in high-efficiency applications by achieving ZVS from 50% to 100% load. To achieve this high efficiency the UCC28950 was designed to drive synchronous rectifiers on the secondary side of the full bridge converter. The UCC28950 also incorporates a burst mode and DCM function to improve no-load efficiency. Please see UCC28950 data sheet for details (TI Literature Number SLUSA16).

The DCM (Discontinues Current Mode) comparator was designed to turn off the synchronous rectifiers before the output current reaches critical conduction at lighter loads (< 20%). This does two things. First it removes the energy that is required to drive the FETs at lighter loads. Second the DCM feature prevents the output inductor from developing a negative current that can damage the output synchronous rectifiers under no load/transient conditions.

Specifications

Manufacturer	Texas Instruments
Category	AC/DC and DC/DC Conversion
Sub-Category	AC/DC SMPS - Single Output
Eval Board Part Number	296-28920-ND
Eval Board Supplier	Texas Instruments
Eval Board	Normally In Stock
AC Voltage	230 V
Outputs and Type	1 Isolated
Voltage Out	12 V
Current Out	50 A
Output Power	600 W
Features	Light Load Mode
Efficiency @ Conditions	>95%, 390V in, 12V @ 15 ~ 37 A >94%, 390V in, 12V @ 10 ~ 50 A
No-load Input Power @ Voltage	500 mW @ 390V
Switching Frequency	- Not Given
Internal Switch	No
Component Count + Extras	135 + 6
Voltage In	370 ~ 410 VDC
Design Author	Texas Instruments
Application / Target Market	Servers Telecom
Main I.C. Base Part	UCC28950
Date Created By Author	2010-05
Date Added To Library	2012-11