UCD3138: 1kw 800V to 14V dc dc converter topology

Sandip,

We will need more details to narrow down the topology selection. But please refer to the reference designs below as they are close to your initial requirement. 

https://www.ti.com/tool/PMP40586

https://www.ti.com/tool/PMP20978

Generally, LLC or phase shift full bridge topology are recommended here.

Hello Sandip,

Other considerations could be power density, desired complexity, etc. At 1kW, both LLC and PSFB are common. UCD has resources for both LLC and PSFB topologies. I do not believe we have 800V input designs but we do have 1kW designs for both HB-LLC and FB-LLC. You can scale these designs to match your parameters (Ex. change the turns ratio, component selection, etc.) See the below links for more details on the comparison between the two topologies and the examples TI provides for UCD:

LLC vs. PSFB

• https://www.ti.com/video/series/phase-shifted-full-bridge-psfb-vs-full-bridge-llc-fb-llc.html 
• https://forum.allaboutcircuits.com/threads/full-bridge-llc-vs-phase-shifted-full-bridge.186003/
• https://ieeexplore.ieee.org/document/9842914
• https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1120461/ucd3138fw-psfb-comparing-psfb-with-llc 

Half-Bridge LLC (HB-LLC)

• UCD HB-LLC EVM (340W): https://www.ti.com/tool/UCD3138ALLCEVM150 
• TIDA-00512 (348W): https://www.ti.com/tool/TIDA-00512 
• PMP4435 (300W): https://www.ti.com/tool/PMP4435
• PMP21842 (504W): https://www.ti.com/tool/PMP21842 
• PMP21309 (504W): https://www.ti.com/tool/PMP21309 
• PMP20978 (1kW): https://www.ti.com/tool/PMP20978 
• UCD HB-LLC Firmware: https://www.ti.com/tool/UCD3138FW_LLC 

Full-Bridge LLC (FB-LLC)

• TIDA-00381 (360W): https://www.ti.com/tool/TIDA-00381
• PMP40586 (1kW): https://www.ti.com/tool/PMP40586 
• PMP23340UCD (1.32kW): https://www.ti.com/tool/PMP23340UCD 
• UCD FB-LLC Firmware: https://www.ti.com/tool/UCD3138FW-FBLLC 

Phase Shifted Full Bridge (PSFB)

• UCD PSFB EVM (360W): https://www.ti.com/tool/UCD3138PSFBEVM-027 
• TIDA-00412 (360W): https://www.ti.com/tool/TIDA-00412 
• PMP4320A (600W): https://www.ti.com/tool/PMP4320A 
• UCD PSB Firmware: https://www.ti.com/tool/UCD3138FW-PSFB 

Regards,

Jonathan Wong

Hello Sandip,

The transformer design for a PSFB topology will be similar. Most of TI's designs are Vin = 400V due to universal AC input but the 800V can be scaled by changing the transformer turns ratio. PMP4320A is probably the most relevant design for your application. 

See the following app note for PSFB design: https://www.ti.com/lit/ug/tidu248/tidu248.pdf 

Regards,

Jonathan Wong