UCC28610: UCC28610 Brown out

John Hsiao

Part Number: UCC28610

When UCC28610 detect brown out threshold, how fast controller will stop switching? Since it did not specify on datasheet, thanks.

over 4 years ago

0 Mike O' over 4 years ago

TI__Guru 70515 points

Hello John,

The converter will not shut down to a fault unless it has occurred in 3 switching cycles. So the input under voltage needs to be detected in three consecutive switching cycles.

Even though the delay is not specified the ZCD delay of 150 ns is specified. So the delay time after initial brownout could vary from

3/fmin + 150ns to 3/fmax + 150 ns.

Also note when the line is removed there will be a delay due to the bulk capacitor discharge.

dt = (Cbulk/Iin)*(Vin - Vin@BrownOut.

So the total variation would be

(dt+3/fmin + 150ns) to (dt + 3/fmax + 150 ns.)

Regards,

0 John Hsiao over 4 years ago in reply to Mike O'

TI__Prodigy 445 points

For overload detection, is it the same converter will not shutdown to a fault unless it has occurred in 3 switching cycles?

0 Mike O' over 4 years ago in reply to John Hsiao

TI__Guru 70515 points

Hello,

I believe this is correct.

Regards,

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UCC28610: UCC28610 Brown out