Whats this device ??? - Page 1
Forum section: electronics / projects

author: Big_Al
author_rank: Contributor
timestamp: May 05, 2013, 01:29:39 pm
content: Hi All,Just about to give up trying to figure out exactly what part number this device is (photo attached).I guess its some sort of Gate driver, its driving 3 powet FET's in the PFC stage in my Sony plasma tv psu (PSE-324). As you can guess there is no schematic for the psu board in this particular model, it was made externally for Sony.Maybe one of you lot might know what it is !I've labelled up the signals I can tell to help with the pin-out. Its a SOT23 type package size.If it comes to it I'll have to bodge something else in its place.Thanks in advance.Al.

author: jebcom
author_rank: Regular Contributor
timestamp: May 05, 2013, 02:29:26 pm
content: Hello Big Al,Am I correct to assume that you have lost the gate drive and are trying to repair the problem?You said there's no schematic, but you have traced it to driving the MOSFET gates. Have you made a partial schematic of the gate connections, the mystery device, and any other related components that you might have noticed to be connected? If you can provide some more info like that, it may help someone make an educated guess about exactly what your device is doing.Also, just curious, what country are you from? You can go into your profile and enable a country flag to be shown in your posts.

author: Big_Al
author_rank: Contributor
timestamp: May 05, 2013, 04:27:22 pm
content: The device is definately faulty, its drawing excess current. The problem is finding out what its part number is.The PFC IC is driving into this instead of directly driving the MOSFET Gates, I presume thats because it has to drive three MOSFETS instead of the usual one and so they have chosen to use this driver due to the capacitive loading of the gates.The MOSFETS are fine and also the drive into this IC. Each Mosfet Gate (N-Channel) is simply fed by a 10ohm resistor. The MOSFETS are simply driving a coil in a boost configuration.The signal input to this IC is fed via a series 100ohm resistor, and the V+ to this IC is fed via a series 20ohm resistor.The device is screened as 'Q' on the silk screen instead of 'IC', so may be a kind of totem pole driver maybe ?? Don't know.I'm from the UK by the way.

author: jebcom
author_rank: Regular Contributor
timestamp: May 05, 2013, 05:00:41 pm
content: I suppose that part number is a house number.You're probably right about the push-pull output.Maybe you've already searched this far, but here are some possibilities from Mouser:http://www.mouser.com/Semiconductors/Integrated-Circuits-ICs/Power-Management-ICs/Power-Driver-ICs/_/N-6j773?P=1z0z33q&Keyword=mosfet+gate+driver&FS=TrueI wonder if any of these would make sense?

author: Big_Al
author_rank: Contributor
timestamp: May 05, 2013, 05:27:09 pm
content: Thanks for that jebcom.I'll have a browse through those and see if there's a match.Al.

author: envisionelec
author_rank: Frequent Contributor
timestamp: May 06, 2013, 05:05:28 am
content: Quote from: Big_Al on May 05, 2013, 01:29:39 pmHere ya go:CPH5506http://www.onsemi.com/pub_link/Collateral/CPH5506-D.PDFI do this all the time in my line of work.

author: Big_Al
author_rank: Contributor
timestamp: May 06, 2013, 01:55:45 pm
content: Nice one indeed matey. You are a true God !!It's spot on that one.Thanks a lot.Al.

author: w2aew
author_rank: Super Contributor
timestamp: May 06, 2013, 03:35:21 pm
content: Good job on the find! I've always had spotty luck with finding parts using the cryptic markings often found on SMTs, so any insight to the methods you use to find these parts would be very useful to a lot of us!

author: jebcom
author_rank: Regular Contributor
timestamp: May 06, 2013, 05:13:35 pm
content: QuoteYouAREthe man, envisionelec!

author: krivx
author_rank: Frequent Contributor
timestamp: May 06, 2013, 05:23:38 pm
content: Quote from: envisionelec on May 06, 2013, 05:05:28 amSo how did you do it? Curious minds must know.

author: elgonzo
author_rank: Unknown
timestamp: May 06, 2013, 05:36:48 pm
content: Quote from: envisionelec on May 06, 2013, 05:05:28 amWow! You surely must be working in the "Black Magic" department

author: envisionelec
author_rank: Frequent Contributor
timestamp: May 06, 2013, 06:24:18 pm
content: Quote from: w2aew on May 06, 2013, 03:35:21 pmGoogle has all the answers.First, I knew it was a Totem driver based on the circuit description. Once I eliminated the usual Micrel, ST and other active devices and assumed that a TV would use the cheapest parts, I went searching for the SMD code book I got from a Scribd page last year. There were several EF, but only one SOT25-5. I knew it was the Sanyo part because Japanese manufacturers are loathe to use anything else.

author: w2aew
author_rank: Super Contributor
timestamp: May 07, 2013, 02:17:18 am
content: Quote from: envisionelec on May 06, 2013, 06:24:18 pmAhh - that SMD code book is a key part! Do you have a link?

author: amyk
author_rank: Super Contributor
timestamp: May 07, 2013, 10:08:13 am
content: Was it a private copy someone had been updating? I checked the "official" SMD Codebook athttp://www.marsport.org.uk/smd/mainframe.htmand a few mirrors, but couldn't find the right EF.

author: envisionelec
author_rank: Frequent Contributor
timestamp: May 07, 2013, 02:45:29 pm
content: Quote from: w2aew on May 07, 2013, 02:17:18 amSMD_markcodesForgetting where it was, I just searched 'scribd CPH5506'Scribd is also a great place to find schematics that exist for $25 on other sites. Everything is on the internet. Everything.

author: elgonzo
author_rank: Unknown
timestamp: May 07, 2013, 02:49:11 pm
content: Quote from: envisionelec on May 06, 2013, 06:24:18 pmThat's quite some experience and skills you got