UCC25800-Q1: Load transient questions

Hello,

The blue waveform is +15V and the cyan is -4V like the other waveforms in the test report. The pink waveform shows a step waveform of the applied load. When the load increases, the -4V output will temporarily spike toward 0V and then fall back down to a transient. When the load is released, the -4V output will return to a constant -4V. On the other hand, the +15V output will stay almost constant despite the change in load.  

Regards,

Jonathan Wong

Hi,

You can refer to this E2E post about the noise on a dual rail output: https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1169280/ucc25800-q1-one-transformer-w-2-secondaries-for-sic-gate-drive-bias?tisearch=e2e-sitesearch&keymatch=UCC25800-Q1%25252525252525252520crosstalk#. 

You can view this resource for information on the UCC25800 design:https://www.ti.com/seclit/ml/slup401/slup401.pdf. Specifically, slide 25 shows that since there are 2 transformers there will be minimal noise.

Regards,

Jonathan Wong