Diode identification - help

[valentino_val]

Hi , need help with one diode marked as ED 51 (Mercedes ABS module). I need to replace it, it's blown. It's Vishay diode size DO-214AB. From Vishay web page datasheets I don't found this diode.
I thought this is TVS diode, but it's not grounded . I Don't know!

[valentino_val]

Re: Diode identification - help

at the same PCB have another diode also marked as ED, but it is less than the blown

[stj]

Re: Diode identification - help

SMBG110C OR SMBJ110C in my databook
maybe

[valentino_val]

Re: Diode identification - help

SMBG110C OR SMBJ110C in my databook
maybe

Thx stj! SMBG110C and SMBJ110C are TVS diodes, if is TVS diode probably will be TPSMC18 (by Vishay datasheets), but standard use of these diodes is to protect ICs and normally they are grounded, but this is not. The small (marked as ED 4C) is grounded. I sent email to Vishal, I hope to answer me quickly.

[stj]

Re: Diode identification - help

EGF1D
ES1D
ES1PD
ES2D
ES3D

all made by Vishay with the code ED

[fzabkar]

Re: Diode identification - help

The TPSMC18 diode has a marking code of EDP, so it doesn't seem to fit. However, the standoff voltage (14.5V) is what you would expect from an alternator when it is charging.

Do these diodes shunt solenoids? If so, then they could be back-EMF suppression diodes. I would look for connectivity between each diode and the valves and pump motor. It would also be advisable to see if and how they connect with the switching MOSFETs.

The BUK7624 and BUK9624 are N-channel MOSFETs, so they would be switching the ground side of the load.

The BTS409L1 is a high side switch, so it would be switching the 12V side of the load.

BTS409L1, Siemens, PROFET, Smart Highside Power Switch, 5.0V - 34V, 2.3A:


BUK7624-55A, NXP, TrenchMOS standard level FET, N-channel, 55V, 47A, 24mohm RDSon:


BUK9624-55A, NXP, N-channel TrenchMOS logic level FET, 55V, 46A, 26mohm RDSon:


Transient Voltage Suppressors Interactive Databook, Vishay:

[CapLeaker]

Re: Diode identification - help

I think it is a high voltage 1A diode. Jam something ultrafast, high voltage that has at least 1A in there.

[fzabkar]

Re: Diode identification - help

ISTM that the smaller diode may 1A while the larger one may be 2A or 3A.

My searches turn up the same candidates as previously mentioned.



https://cdn.badcaps-static.com/pdfs/...722c2fb3f5.pdf

https://cdn.badcaps-static.com/pdfs/...8e98402ea4.pdf
https://cdn.badcaps-static.com/pdfs/...9b1af1fa03.pdf
https://cdn.badcaps-static.com/pdfs/...d04c5c7ee8.pdf

[valentino_val]

Re: Diode identification - help

Thanks guys!
The diode is connecting as the blue and purple lines (as the image - tested with desoldered MOSFETs)
Only ES3D (https://cdn.badcaps-static.com/pdfs/...8e98402ea4.pdf) in corresponds 100% to the parameter of the diode (the marking code and the size).
In the PCB visually detected 2 problems (marked in yellow) – the diode and burned/broken line bottom of BUK9624 (the drain). The diodes 9XW, JSs, WT6 are tested. The N-channel MOSFETs - BUK7624, BUK7614 and BUK9624 are tested (the images) + swiching test.

[valentino_val]

Re: Diode identification - help

Can I replace this ES3D it with MUR420 (axial 4A 200V)? --> https://cdn.badcaps-static.com/pdfs/...25b71870c2.pdf

*have only this in my town electronic store

[fzabkar]

Re: Diode identification - help

The MUR420 seems OK to me (although its trr is slightly slower).

I confess I don't understand the circuit, though. The BUK9624 appears to be switching the grounded end of a valve, and the diode appears to be suppressing the back-EMF. However, I would have expected that the cathode would then connect to the +12V supply. Instead it goes to the source pin of the BUK7624, which I would have expected to be grounded.

[valentino_val]

Re: Diode identification - help

The MUR420 seems OK to me (although its trr is slightly slower).

I confess I don't understand the circuit, though. The BUK9624 appears to be switching the grounded end of a valve, and the diode appears to be suppressing the back-EMF. However, I would have expected that the cathode would then connect to the +12V supply. Instead it goes to the source pin of the BUK7624, which I would have expected to be grounded.

Thx!
I also don't understand the circuit.
Tomorrow I will replace it and report here.

[valentino_val]

Re: Diode identification - help

All fine , with replace the diode (with MUR420) and point the broken line!