Help identifying a sensor (I think) - Page 1
Forum section: electronics / repair

author: pcee
author_rank: Regular Contributor
timestamp: September 05, 2021, 08:21:52 pm
content: Oh the joys when things are too small to put adequate identifying markings on them!Unfortunately, searching for C017 doesn't provide any useful hits, so this is probably a production or lot code.The package is 2mm x 2mm x ~0.8mm high. The pin layout appears to be 3 along the top and bottom, and 2 along each side, for a total of 10 pins. The large rectangle toward the bottom right corner is polished and glossy, which is why I suspect it's a sensor. I was also able to identify SCL and SDA lines, so I know it uses I2C.So far I've tried searching for QFN10 2x2 sensors, but the Si114x/Si115x sensors have 4 pins on top and bottom with 1 on the sides, rather than the above arrangement. Is there a package designation that applies only to the 3+3+2+2 arrangement?Any other ideas for how I could chase this down?

author: StillTrying
author_rank: Super Contributor
timestamp: September 05, 2021, 08:57:00 pm
content: Light sensor/meter ?

author: amyk
author_rank: Super Contributor
timestamp: September 05, 2021, 08:59:44 pm
content: Perhaps you could tell us what it's out of and what it measures?

author: pcee
author_rank: Regular Contributor
timestamp: September 05, 2021, 09:05:55 pm
content: I don't know what the sensor measures, if anything, since the device doesn't have any apparent need for one.

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: September 06, 2021, 03:01:29 am
content: Have you tried to narrow it a bit by the logo? (using a good magnifier should give you a better view than that picture offers, and there are directories for the IC logos on the internet)Also, that could well read CG17, methinks.

author: fzabkar
author_rank: Super Contributor
timestamp: September 06, 2021, 03:22:14 am
content: Same package?https://www.st.com/en/mems-and-sensors/pressure-sensors.htmlhttps://export.rsdelivers.com/product/stmicroelectronics/lps25hbtr/stmicroelectronics-lps25hbtr-surface-mount-mems/1106550FWIW, some hard drives have an analogue barometric pressure sensor in a tiny square grey package with a tiny vent hole (?) in the centre. These devices are marked, from memory, "CO32" or "C032", on both Seagate and Western Digital drives. They consist of 4 strain gauges in a Wheatstone bridge arrangement. The external signal conditioning circuitry consists of two op amps. One amp provides a constant current source for the bridge, the other is a differential amp for amplification and buffering.

author: pcee
author_rank: Regular Contributor
timestamp: September 06, 2021, 02:17:10 pm
content: Quote from: fzabkar on September 06, 2021, 03:22:14 amWow, that's really close! I think you're on the right trail. HLGA-10 seems closer to the right form factor than QFN: the pads are slightly inset from the edge, unlike QFN. The pin diagram in the data sheet for that part also matches what I've identified on the board.The only differences I observe are:1. The part you found is 2.5mm x 2.5mm, and this part is 2mm x 2mm. (Edit: TheLPS22CHandLPS22HBare both the right dimensions!)2. The logo doesn't look like ST to me (see below).Quote from: Neomys Sapiens on September 06, 2021, 03:01:29 amGreat idea, I had assumed it was just a circle pin 1 marker! At your prompting I managed to dig up one more magnifier I hadn't tried yesterday, and got the attached higher-resolution image. I haven't been able to find that logo in my searches so far.

author: fzabkar
author_rank: Super Contributor
timestamp: September 06, 2021, 06:51:15 pm
content: FWIW, these parts appear to have the same pinout, albeit with a missing feature (no SPI):https://invensense.tdk.com/wp-content/uploads/2018/01/DS-000186-ICP-101xx-v1.2.pdfCould the pinout follow a standard?BTW, it might be useful to include "MEMS" in your search terms.Edit: Could this be it (the logo seems to match)?https://int.rsdelivers.com/product/wurth-elektronik/2511020213301/wurth-elektronik-2511020213301-surface-absolute/2025924https://www.we-online.com/catalog/en/manual/2511020213301_WSEN-PADS%202511020213301%20Manual_rev2.1.pdfhttps://docs.rs-online.com/0c08/A700000006942877.pdf

author: amyk
author_rank: Super Contributor
timestamp: September 06, 2021, 09:22:30 pm
content: I don't think it's a logo, but rather a rough laser-etched pin 1 marker.

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: September 06, 2021, 09:42:00 pm
content: Quote from: amyk on September 06, 2021, 09:22:30 pmUnfortunately you could be right. That earlier picture made it look like a logo. Dang, that is often a very helpful approach.

author: fzabkar
author_rank: Super Contributor
timestamp: September 07, 2021, 02:14:14 am
content: Quote from: amyk on September 06, 2021, 09:22:30 pmBut the markers appear to be etched with the same pattern of bumps(?).

author: pcee
author_rank: Regular Contributor
timestamp: September 07, 2021, 12:37:47 pm
content: Thank you all for your help!I think I've satisfied myself that it's a tiny HLGA-10 pressure sensor. If it turns out it matters whose it is, I can probably figure that out with some I2C sniffing and data sheets.