Got a China made 4.5v smp power supply that has broken down and it seems to be it's device for monitoring voltage and current output located on its low voltage side.
Unlike most supplies which the optocoupler diode is at ground level fed via say a zener or under a TL431 control, this one is fed via a resistor from + side and its lower end goes to this smd device, which I can understand, as at 4.5v regulation begins to get a bit sloppy due to a lack of workable voltage room.

So I wonder if anyone can give me a clue as to what this part true number may be, it has M801 on one side with E506 beneath. An LT4430 has been put forward but pin outs are wrong, with most copies of semiconductors I find they are TI chips so wonder if its one of theirs in a new form.

The wires are for low voltage output but polarity is reversed as it feeds an old radio with negative centre pin.

Many thanks for any help

David

 

Might it be this, or some variant?

 

Thank you for that idea but connections do not fit, I have been searching though and have come up with a chip but its terminals are wrong plus has 8 connections where I look for a 6 pin item, but a circuit shows the type of design that this power supply is using so hope it may jog an idea from anyone.

David