Off-Line PWM Controller with Integrated Power MOSFET


This is my first post in this Forum. I hope some one can help me. I am trying to find a Power IC chip in my Yamaha Amplifier. The Chip is called STR3A453. Just wandering if there is a substitute for it i can buy ?


This appears to be a non-isolated buck controller from Sanken, which we do not currently stock though it does appear to remain in production.

Replacement with the same would be recommended, as devices such as this are not particularly standardized across manufacturers and the surrounding components would have been adapted to its particular behaviors. It is also uncommon for the controller of an offline switching IC to fail in isolation; it’s unlikely that a successful repair could be effected by replacing this particular item.

I agree with Rick. There are likely other failed parts in the power supply circuit which would also need replacing before things would function properly again. And, using any other part is likely to be, at best sub-optimal, and may not work at all, for the reasons he stated.

With all that being said, if the alternative is trashing the whole amplifier, we do have stock of the STR3A153, an older version which has the same pinout, and a quick scan of the specs look fairly similar.

No guarantees it will work. I would try to source the STR3A453 first, but if the alternative is trashing the whole thing, this might be worth a shot.

Thank you David for your reply. I have checked the specs of this chip and its almost exactly the same as STR3A453. I have already ordered it through your website. I have checked all other components
in the circuit (Diaodes, caps, transistors and resistors) and they are all fine. It’s a Yamaha AV receiver and it failed with a power surge. I will use this, other wise will order a new replacement power supply.


Shahdad Khan