Brushless motor transistor board mystery parts and topology - Page 1
Forum section: electronics / beginners

author: sonnytiger
author_rank: Frequent Contributor
timestamp: July 30, 2013, 04:40:58 pm
content: I took apart an electric power steering pump off of a newer car and was surprised to find a brush-less DC motor in it. I plan on using the motor part as generator, but I also took a look at the somewhat ruined drive electronics. There are two boards, one with control stuff on it and another with a metal backing that has the MOSFETs mounted on it. I was looking up these devices, trying to find something on them, but came up blank. As you will see in the picture, there are four different devices, one has no text on it at all, one has p2n04l03 and ak038 in smaller print on it, another has n0403 and ac 42 in smaller print on it and the final one has n0403 and ad042 in smaller print on it. This seems strange as you would think there would be all the same devices on it, unless it is something more than just the switching transistors. Other than these devices, there are some diodes and capacitors. My goal is to basically try and use it to spin the motor if I want to use it for that instead of as a generator, I am interested in finding out what topology it is using.Thanks!

author: free_electron
author_rank: Super Contributor
timestamp: July 30, 2013, 04:51:42 pm
content: protected mosfets. these sense overcurrent and sht themselves off. custom part made by infineon. not avaialble on the market

author: Short Circuit
author_rank: Frequent Contributor
timestamp: July 30, 2013, 04:58:03 pm
content: Appears like a standard 3-phase bridge.Lowside are probably logic level FETs (hence the 'L' in the partno) to allow for direct drive from 3.3 or 5V logic.Not needed for the highside FETs as those need bootstrapped levelshifters anyway.

author: c4757p
author_rank: Super Contributor
timestamp: July 30, 2013, 05:00:46 pm
content: I like that hefty SMD current shunt... anyone know if they are sold anywhere in low quantity?

author: sonnytiger
author_rank: Frequent Contributor
timestamp: July 30, 2013, 06:15:52 pm
content: Quote from: c4757p on July 30, 2013, 05:00:46 pmI thought maybe that's what it was, dunno where to get one though sorry.

author: sonnytiger
author_rank: Frequent Contributor
timestamp: July 30, 2013, 06:17:12 pm
content: Quote from: free_electron on July 30, 2013, 04:51:42 pmThink its possible to drive it? I can't use the original circuit as it is probably non function (was soaked in water for some time.)

author: Zero999
author_rank: Super Contributor
timestamp: July 30, 2013, 07:57:25 pm
content: The top right hand MOSFET also appears to have a crack in the case.

author: sonnytiger
author_rank: Frequent Contributor
timestamp: July 30, 2013, 09:13:42 pm
content: Quote from: Hero999 on July 30, 2013, 07:57:25 pmit must have been a hair or something cause i cant see it

author: poorchava
author_rank: Super Contributor
timestamp: July 31, 2013, 09:08:08 am
content: Quote from: free_electron on July 30, 2013, 04:51:42 pmNot exactly true:Note, that those devices have tab connected to one trace, first lead is a single signal, and all the remaining 5 leads are connected to one fat trace. High power protected switches usually have more signal leads for diagnostic purposes (like external current-mirrored current output). Those are N-MOSFETs in7-lead packages. They do that because single leads in TO263 cannot handle such large currents. They don't do that for P-MOSFETs.This must be from a 12V passenger car, because in 24V vehicles (like most trucks) power devices are typically rated for 55V and higher.P2N04L03 = IPB160N04S2L-03**n0402 according to Infineon's naming convention will be a 40V 2mOhm N-Mosfet. TO-263-style package means it will be IPB series. I would guess one of those:IPB180N04S3-02IPB160N04S4-02DInfineon's naming format for automotive mosfets is following:IPabbbcddee-ffIP- infineon power mosfetsa - package symbol (B = D2PAK)bbb - current ratingc - N for N-channel, P for P-channeldd - rated voltage divided by 10ee - semiconductor technology. S2 = optimos, S3 = optimos-t S4 = optimos-t2ff-Rds in miliohms.As for the high-current shunts I would bet on custom stuff from Isabellenhütte.

author: amyk
author_rank: Super Contributor
timestamp: July 31, 2013, 10:22:07 am
content: I was going to post the IPB160N04S2L-03 too... and I think the other one is the IPB160N04S2-03 (without the L - has higher Vgs(th) - extra margin to avoid shoot-through?). It looks like there's 3 of each.GL{1-3} and GH{1-3} are obviously gate inputs for low and high.

author: poorchava
author_rank: Super Contributor
timestamp: July 31, 2013, 01:45:26 pm
content: Quote from: amyk on July 31, 2013, 10:22:07 amYou are right. For some reason I was looking for N0402 rather than N0403.@OP: what sort of bridge drive do they use? A dedicated chip (Infineon does those too), a gate driver + CPU or some sort of discrete gate drive (most automotive ECUs I've seen have some sort of general usage charge pump to generate voltage above rails in order to be able to use N-mosfets for all possible tasks instead of p-channel ones.

author: sonnytiger
author_rank: Frequent Contributor
timestamp: July 31, 2013, 03:08:26 pm
content: Quote from: poorchava on July 31, 2013, 01:45:26 pmyes it is from a passenger car, only a couple years old. The pump assembly had another board with drive electronics, including a large chip and a couple 16 pin packages. I wouldn't mind drawing out the schematic of the transistor board, but im not sure which pins are which. The tap on the devices would be the drain right? the single pin the gate and the other 5 the source?