UCC25600: When the switching Frequency is about 280KHz or 300KHz, it's in Continuous mode, and the UCC25600's temperature is very hot, 110'C.

Xianrong Shang

Part Number: UCC25600

Hello! I design the UCC25600 according to the datasheet's reference drawings, the GD1,GD2, then Push-pull transistor of totem, then the driver transformer, then the NMOSFETs, then the power transformer.

When the switching Frequency is about 100KHz, the UCC25600 works normally.

When the switching Frequency is about 280KHz or 300KHz, it's in Continuous mode, and the UCC25600's temperature is very hot, 110'C. Why? I haven't find the reason.

over 6 years ago

0 Benjamin Lough over 6 years ago

TI__Mastermind 26215 points

Hi Xianrong,

Thanks for your interest in UCC25600. Have you measured the current going into the VCC pin? The device is likely consuming more current at higher switching frequency. Under what test conditions are you operating at 280kHz to 300kHz? Are you able to share your schematic?

Best Regards,
Ben Lough

0 Benjamin Lough over 6 years ago in reply to Benjamin Lough

TI__Mastermind 26215 points

HI Xianrong,

Did you have a chance to measure the ICC current? Are you able to share your schematic? If you would like, you can limit the maximum switching frequency by connecting a resistor between the opto and the RT pin.

Best Regards,

Ben Lough

0 Benjamin Lough over 5 years ago in reply to Benjamin Lough

TI__Mastermind 26215 points

Hi Xianrong,

Its been ~2 weeks since your last response. I will go ahead and close this thread for now. If you have any follow up questions please feel free to make a new post.

Best Regards,
Ben Lough

0 Xianrong Shang over 5 years ago in reply to Benjamin Lough

Intellectual 855 points

ok.

Power management

Power management forum

UCC25600: When the switching Frequency is about 280KHz or 300KHz, it's in Continuous mode, and the UCC25600's temperature is very hot, 110'C.