SMD marking code - help

[redwire]

I need help identifying an SMD marking code "GGUAA" or maybe it's "66UAA", the G and 6 look the same.
The part is a 6-pin SOT23-6 and looks like an instrumentation amp or comparator.

Any help is appreciated.

National Semi apparently uses "AA" as the die run code.

[selldoor]

Re: SMD marking code - help

Can we have a picture of it?

[redwire]

Re: SMD marking code - help

It's conformal coated and very small, I don't have a macro lens. The pic here is of a SOT23-6.

[selldoor]

Re: SMD marking code - help

Yeh I know what a sot23-6 looks like - I just wanted to verify the marking.
Not that I dont trust you just that over time we have spent hours on here looking for
parts - having been given the wrong numbers in good faith. I know you said GG could be 66
but if possible I like to see for myself.
Nearest I found was something like a 6GU sot23-5 yours def has 6 legs?

[redwire]

Re: SMD marking code - help

I stared at the part for an hour with a magnifier and pretty sure it's "C6UAA" marking in a 6-pin package. An op-amp I think. Very hard to see difference between G/6/C with bubbly conformal coating

I ended up here: SMD marking database but the pinout does not match the AD7278 (C5U)

Thanks for any digging

[budm]

Re: SMD marking code - help

https://cdn.badcaps-static.com/pdfs/...776967a551.pdf

Trace out pin 6 (Vs+) to see if it is connected to the + of the power supply, and see if pin 2 (Vs-) is connected to the Negative if isi an OPAMP.
What kind of board this part is on?

[redwire]

Re: SMD marking code - help

The part is on a board for furnace flame (ion) detection. I guess it's a CMOS comparator or op-amp, but 4 layer PCB and I can't follow all traces.

Pin 1 - goes to flame rod through 3.2meg resistor
Pin 2 - GND
Pin 3 - goes to 20k resistor to pin 2
Pin 4 - GND
Pin 5 - +5V
Pin 6 - goes to small capacitor

[budm]

Re: SMD marking code - help

Well those pins connections as you posted does not have typical pin out for the typical OPAMP in SOT23-6.

[Elysarian]

Re: SMD marking code - help

A quick trawl of the internet has turned up a possible candidate...

The device (extrapolating from your pin-out descriptions and what it's used in) could be an ADC?

I found this datasheet via a Russian website referencing the C6U part of your description:

https://cdn.badcaps-static.com/pdfs/...580de81d85.pdf

I am, of course, guessing here

[redwire]

Re: SMD marking code - SOLVED

It is a Vishay high-voltage SPST CMOS switch DG448

Best SMD marking code database I found is this Russian site tomsk.ru A bit slow and not always up... but it beats Google. Thanks for everyone's help

[Agent24]

Re: SMD marking code - SOLVED

Best SMD marking code database I found is this Russian site tomsk.ru A bit slow and not always up... but it beats Google. Thanks for everyone's help

Ooh, that's a good one. Haven't seen that site before!