UCC28600 Over current protection

bfarkas

Other Parts Discussed in Thread: UCC28600

Dear TI

I design a QR flyback PSU with UCC28600 and I would have a question. In datasheet the PL threshold can be 1.05V...1.37V and CS offset voltage can be 0.35V..0.45V but in figure 12 the threshold for CS peak votlage is seems to me quite constant. so my question is the PL threshold and CS offset together have got small changes or the fig 12 is a typical curve only. It is important because of over current protection because if the PL and CS offset tolerance is independent from each other the PL threshold voltage for CS peak votlage can be 0.6 V (1.05-0.45) but it can be 1.37-0.35=1.02V it means too high variation.

So in my design can use fig12 or I have to design based worst case tolerance situation in the case of over current protection.

Thanks for suport in advance

over 13 years ago

0 Lisa Dinwoodie over 13 years ago

TI__Genius 15910 points

The CS and PL will track each other. If CS is on the low end of the range, then PL will also be on the low end of the range. The wide range is for any and all devices coming off of the assembly line, and it accounts for lot to lot variation, production and temperature tolerances, each individual part will have a much tighter range.

0 bfarkas over 13 years ago in reply to Lisa Dinwoodie

Prodigy 20 points

Thanks you for fast response.

May I get some document which verify that CS and PL track each, because I didn't information about it in datasheet .

0 Lisa Dinwoodie over 13 years ago in reply to bfarkas

TI__Genius 15910 points

I will see what I can get from the Sustaining group and let you know

0 Lisa Dinwoodie over 13 years ago in reply to Lisa Dinwoodie

TI__Genius 15910 points

Sustaining has confirmed that the PL threshold and the CS offset will track each other

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UCC28600 Over current protection