help identifying broken IC

[ALPI]

I yesterday received a small switching powersupply (230 VAC in ; 6 VDC
out). It doesn't go anymore.
I opened it and find a broken 8-pins IC. I can only read 5R as the end
of the IC id. A small description of the signals at the pins :
1 : not connected (nc)
2 : common (-)
3 : received via a resistor the activating current from the rectified
230 VAC (= 320V DC) and from a diode the transformator (EI-25).
4 : input from the EL817 optocoupler
5 : NC
6, 7 and 8 : soldered together and connected to the transformator
Other components of the switching powersupply : KA431 = TL 431.

Can anybody help me to identify the IC ?

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[Franc Zabkar]

On Sat, 17 Jul 2004 20:47:28 +0200, ALPI
<alain.pinchemail_nospam@skynet.be> put finger to keyboard and
composed:

I yesterday received a small switching powersupply (230 VAC in ; 6 VDC
out). It doesn't go anymore.
I opened it and find a broken 8-pins IC. I can only read 5R as the end
of the IC id. A small description of the signals at the pins :
1 : not connected (nc)
2 : common (-)
3 : received via a resistor the activating current from the rectified
230 VAC (= 320V DC) and from a diode the transformator (EI-25).
4 : input from the EL817 optocoupler
5 : NC
6, 7 and 8 : soldered together and connected to the transformator
Other components of the switching powersupply : KA431 = TL 431.

Can anybody help me to identify the IC ?

It's probably a PWM SMPS controller with integrated MOSFET. Something
like the TOPSwitch series from Power Integrations, although your part
does not seem to be one of theirs.

See http://www.powerint.com/datasheets.htm

Pins 6,7,8 probably connect to the source of the MOSFET, pin 2 is the
drain, 4 is the control/feedback pin, and 3 is probably the power pin
for the IC.

You may wish to check this IC for some ideas:
http://www.powerint.com/PDFFiles/top242-250.pdf


- Franc Zabkar
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