Help identify a SOT-23-5 IC with a funky pinout - Page 1
Forum section: electronics / beginners

author: timewalker75a
author_rank: Newbie
timestamp: November 10, 2023, 09:21:40 am
content: Hi there,Made a bit of a boo-boo and plugged something that normally runs on 5V into a 20V source, 'cause USB-C ..The component (in fact, there's two identical ones that blew) in question has a marking of OH=E1Y, it's a SOT-23-5 footprint package that has the following pinout going off the PCB traces:1 - VOUT2 - GND3 - NC4 - EN (or CS)5 - VIN (5.1V)I've scoured DigiKey and Mouser and I can't seem to find any LDO/linear voltage regulator or anything else that would fit the aforementioned pin layout. I believe the PCB takes 5V and also outputs 5V to charge the connected devices (controllers). Here's a pic of the aftermath where adjacent components and test points labelled EN and VIN can be seen.

author: Psi
author_rank: Super Contributor
timestamp: November 10, 2023, 10:12:16 am
content: I found this for E1YE1YAP2121AK-3.3TRE1 BCD Semiconductor ManufacturingSOT-23-5 Linear voltage regulator ICLDO, 3.3V±2%, 200mA, +CEE1YIXD5121A329MR-G IXYSSOT-25 Voltage detector IC2.9V±2%, -Reset ODO, +WDEN, Wt=100ms, Rdt=3.13msE1YKSC2859-Y Samsung ElectronicsSOT-23 NPN transistorAF, 35V, 500mA, 150mW, B=120..240, >300MHzE1YXC6121A329MR-G Torex SemiconductorSOT-25 Voltage detector IC2.9V±2%, -Reset ODO, +WDEN, Wt=100ms, Rdt=3.13msE1YXC66DC4128M Torex SemiconductorSOT-25 Linear voltage regulator with volatge detectorLDO, 2.8V±2%, 100mA, Vdet=4.1V±2%, +Reset PPOE1YXC66DC4148M Torex SemiconductorSOT-25 Linear voltage regulator with volatge detectorLDO, 4.8V±2%, 100mA, Vdet=4.1V±2%, +Reset PPOE1YXC66DN4128M Torex SemiconductorSOT-25 Linear voltage regulator with volatge detectorLDO, 2.8V±2%, 100mA, Vdet=4.1V±2%, +Reset ODOE1YXC66DN4148M Torex SemiconductorSOT-25 Linear voltage regulator with volatge detectorLDO, 4.8V±2%, 100mA, Vdet=4.1V±2%, +Reset ODO

author: timewalker75a
author_rank: Newbie
timestamp: November 10, 2023, 10:35:12 am
content: Cheers, that more than I'd stumbled upon in codebooks.I've gone through the current Torex lineup and it all seems to be classic layout of 1 - VIN, 5 - VOUT, whereas the listed XC66 don't bring up any decent results and from a couple datasheets I'd looked at, don't seem to be pin compatible anyway. In fact, only Torex comes up as mfg using SOP-25 package on DigiKey listings. The Samsung IC is of the wrong package. You'd think that leaves me with only AP2121AK-3.3TRE1 to look at, but alast this one also uses a classi LDO pinout of 1 - VIN, 5 - VOUT . Not only that, but the DS is saying the max it goes up to is 3.3V, whereas I believe the original IC is rated at 5V fixed output

author: Psi
author_rank: Super Contributor
timestamp: November 10, 2023, 10:43:02 am
content: yeah, I couldn't find any info on the XC66DN41, its possible its a custom regulator part.But it seems kinda odd to go to the effort to create custom regulator silicon.

author: Psi
author_rank: Super Contributor
timestamp: November 10, 2023, 10:45:17 am
content: FYI, this was were i got that data from.https://smd.yooneed.one/code4531.html

author: wraper
author_rank: Unknown
timestamp: November 10, 2023, 11:07:19 am
content: It's 100% made by Richtek. Part number marking is first 3 symbols. I'm pretty sure first letter is not O, second letter probably isn't H either. Clean it with alcohol for better readability.

author: timewalker75a
author_rank: Newbie
timestamp: November 10, 2023, 11:08:45 am
content: I've touched one of the ICs with a cotton swab and it disentegrated into dust so rubbing it with IPA would probably just get rid of the surface intirely, it's all scorched and bubbled up.I'ts a zero rather than an O, forum boards makes it look more rounded, the second letter is indeed H, there's no other letter with a hyphen between two sticks. Richtek do have some different pinouts to the classic schema, but I couldn't find the one matching these chis

author: wraper
author_rank: Unknown
timestamp: November 10, 2023, 11:10:24 am
content: It's laser marking etched into plastic, nothing bad will happen. Not to say you already know what you can see without cleaning it.

author: wraper
author_rank: Unknown
timestamp: November 10, 2023, 11:14:15 am
content: If it's actually 0H= (you typed O BTW in your first post), then it's RT9742EGJ5https://www.lcsc.com/product-detail/Power-Distribution-Switches_Richtek-Tech-RT9742EGJ5_C3031665.html

author: timewalker75a
author_rank: Newbie
timestamp: November 10, 2023, 11:27:15 am
content: Yeah I know it's etched, just the chip is crumbling from being toasted.Quote from: wraper on November 10, 2023, 11:14:15 amI'm an absolute bafoon then, literally have a piece of paper here with a O stricken through to say it's in fact a 0, apologies!It does appear that you are a 100% spot on though - the pinout matches to a T! Well, except the NC really serving a FLAG purpose, but seem the engineers didn't bother about protection, heh.Thanks a ton for this!

author: wraper
author_rank: Unknown
timestamp: November 10, 2023, 11:29:51 am
content: FLG does not add protection as such, it just informs protection got activated. Most of the time such outputs are not used.