Deciphering mounted chips. Tools available? - Page 1
Forum section: electronics / beginners

author: 240RS
author_rank: Regular Contributor
timestamp: October 14, 2023, 12:28:33 pm
content: I have this pcb (usb phone pre amp) with an ST component that I try to understand. As so often I cannot decipher the model number from all the other packaging numbers. I guess it is a standard problems. Are there scanning apps for it?? Or lookup sites other than digikey etc? Thanks

author: golden_labels
author_rank: Super Contributor
timestamp: October 14, 2023, 01:15:07 pm
content: 20% search engines, component store catalogs and datasheets. 80% experience and ability to choose promising routes and discard unlikely ones. For small SMD components (not big ICs like this) there are also various lists (example#1,example#2).Circuits surrounding the component in question and blocks it is connected to are crucial for identification. Both by narrowing down possibilities and validating guesses.Be aware that customized chips (often found in small, cheap devices) may not have publicly available information.

author: 240RS
author_rank: Regular Contributor
timestamp: October 15, 2023, 11:20:38 pm
content: Good list. Thanks!Anybody an idea what the numbers mean on the ST chip?

author: alligatorblues
author_rank: Regular Contributor
timestamp: October 16, 2023, 12:43:59 am
content: It would help if you took a clear picture from a bit further away. My guess is it's an obsolete mcu.

author: Shonky
author_rank: Frequent Contributor
timestamp: October 16, 2023, 12:45:57 am
content: First step is getting a good picture. Try off angle with lots of light.

author: golden_labels
author_rank: Super Contributor
timestamp: October 16, 2023, 05:18:44 am
content: Also post your guess of what it is written on the chip. You may be wrong (hence the picture is needed too), but your eyes have much better resolution and access to much richer source of information than eyes of people looking at the photo.Tell and, preferably, show us what is around and how this chip connects to the rest of the device.What is that device? Brand, model, exactly.You may also look atSTM32 microcontroller markings referenceto get some hints. It does not contain specific part numbers, but may suggest which fragment is the part number.

author: radiolistener
author_rank: Super Contributor
timestamp: October 16, 2023, 07:23:56 am
content: This is USB sound card? What model?

author: u666sa
author_rank: Frequent Contributor
timestamp: October 17, 2023, 04:16:53 am
content: Quote from: 240RS on October 14, 2023, 12:28:33 pmThis is the number you look for in google search

author: golden_labels
author_rank: Super Contributor
timestamp: October 17, 2023, 07:25:53 am
content: I was thinking about ST33TPHF2XSPI (ST33HTPH2X32AHD4 version), but they come in QFN, not QFP cases. And what would be the role of a TPM chip in an audio amp? Not that I can’t see any, but it would still be weird.

author: Jwillis
author_rank: Super Contributor
timestamp: October 17, 2023, 04:53:16 pm
content: Could you zoom out a bit on the picture? Looks like TQFP-36 or LQFP-36. Could be a USB controller?

author: Kim Christensen
author_rank: Super Contributor
timestamp: October 17, 2023, 05:54:14 pm
content: Looks like it reads PXAHD4

author: 240RS
author_rank: Regular Contributor
timestamp: October 18, 2023, 07:38:11 am
content: That helps me a lot. I have been struggling with so many ICs over the years and only now find out that there is a specific note about markings in data sheets.I always assumed the product name would be printed. Naive…Thanks!

author: radiolistener
author_rank: Super Contributor
timestamp: October 18, 2023, 07:56:51 am
content: any idea what is this chip?

author: Shonky
author_rank: Frequent Contributor
timestamp: October 18, 2023, 10:05:50 am
content: Again with the s*** pictures. Also stop cropping everything thing around it. Sometimes that helps identify it.Looks to be some sort of arm CPU but seems strange its not square? A small Cortex M0 or similar? How many balls? X x Y?Also the arm logo changed to lower case only around 2017 so it's fairly modern. I guess the 4419 gives that away too.