SMD component codes

I didn't find my part, but I have bookmarked these sites for future use. Thanks.

Maybe here

Regards,

Boris Mohar

Got Knock? - see: Viatrack Printed Circuit Designs (among other things)

Another good one for the files.

But on further examination, I am beginning to think the device is something more complicated and proprietary than a couple of transistors. I think it is a dual antenna switch (transmit and receive). It is connected between the antennas on a 2.4 G Hz WAN board. I probably can't get them even if I can identify them. Sigh.

John Popelish said

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There's precious little space to put a component code on SOT23.

I always refer to the data sheet. It's often just one letter and one numeral. Not much help if you don't have the schematic.

Graham

Hello John,

Could it be an arrangement of PIN diodes?

Regards, Joerg

Nope, no link. Two things to consider:

1) Are you sure it's S169 and not 691S?

2) The last character (or two) may be a date code.

Our inventory control system includes the part marking of each approved component (where applicable), so that the parts that we use can be identified and the markings can be searched. Unfortunately, this doesn't help you.

SMD part markings is a major pet peeve of mine. There are many cases where the markings are not specified, even in the data sheet. This is especially true for logic families. When I put a new part in our database I often have to wait to get a sample to see how the part is marked so that I can enter that data. To make matters worse I have seen cases where the markings don't match the format specified in the data sheet, which means that we have to chase after the manufacturer for clarification.

While I'm ranting, it drives me nuts that some manufacturers are using the same part numbers for both lead and lead-free finishes. They publish dates at which the finish will change, but now we have to use date codes to identify which parts are which. We are still trying to figure out how to modify our inventory control system to deal with this, to ensure that parts don't get mixed up. Like, what happens if we need lead-free, and a disti sends us parts with an older date code? Will the disti let us return them? And what then? What happens to our production schedule when these old parts arrive and we suddenly realize that we have to buy newer parts elsewhere? Didn't anyone

*think*?

And then there are things like Vishay formerly BC Components formerly Philips resistors. At least two different part numbers for the same thing, plus a NAFTA part number that does not appear in any data sheet, together multiplied by the number of packaging and lead length options. What a nightmare.

================================

Greg Neff VP Engineering

*Microsym* Computers Inc. snipped-for-privacy@guesswhichwordgoeshere.com

Close. I expect it is a Skyworks AS169-73 SPDT switch, most likely used to select between antennas based on signal strength.

Here's a schematic for a Prism2 WLAN card reference implementation which uses two of these chips, one for antenna discrimination and one for TX/RX switching:

Credit where credit is due, here's the page where I found the above link:

Here is a datasheet for the part:

And what have we here, but a company offering samples and small sale quantities of Skyworks's current RF switch product line (disclaimer--never dealt with these guys):

The AS169-73 is not listed but you might be able to substitute a part with similar specs, such as the AS193-73.

--
Robert Kent
hanuman at ccsi dot com

I think you may be right, The layout is right and the component values I can read match this schematic.

Thank you very much. This is the info I was looking for.