Mp8008 vin voltage

DC-DC Power Converters
1

hi.

I have a question while looking at the EV8008 document.
vin = Flyback controller input supply.
VDD : 37~57V / VIN : 0~35V

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EV8008, transformer aux and VDD are entered into the VIN via Transistor(Q4).
If VDD is entered in VIN , it is out of the VIN range.

I don’t understand this part.
please explain to me

Thank you

2

Hi seungyeon.won,

That is part of the voltage clamping circuit. This will clamp VDD to fit within the range of Vin.

Regards,
Vinh Tran

3

Q4 BASE Voltage limit !
Isn’t vdd into vin without limit?

4

I need to resolve the issue urgently and I’m not sure where else to ask.
reply please.

Thanks.