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I need to identify an SMD diode on a PCB. Does anybody know what it is?

  • Its marking code is 96, there are some dot codes above digits.
  • Its polarity is marked with three lines. -Its dimensions are 3.5 x 2.5 x 1 mm.
  • Its role is freewheeling diode parallel to a solenoid.

Diode With Marking 96

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  • \$\begingroup\$ Dimensions are a SOD128 package. \$\endgroup\$ – Tom Carpenter Nov 7 '20 at 11:41
  • \$\begingroup\$ Thanks But even I can't find anything with this package info. \$\endgroup\$ – Vahid Naim Nov 7 '20 at 11:54
  • \$\begingroup\$ It's an odd package size used commonly by NXP. Were the measurements of the black plastic portion, or did they include the leads? \$\endgroup\$ – Tom Carpenter Nov 7 '20 at 12:00
  • \$\begingroup\$ Rohm is a quite likely manufacturer as they use three bars on their PMDTM package (SOD-128 based) for indicating the cathode \$\endgroup\$ – Tom Carpenter Nov 7 '20 at 12:03
  • \$\begingroup\$ Oooh, so close - that one is 66, with the three bars, and the two groups of dots are the date code. \$\endgroup\$ – Tom Carpenter Nov 7 '20 at 12:08
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Rohm RB055LAM-60 Schottky Barrier Diode in SOD128 Package with marking code 96.


The how:

Firstly, what package is the diode in - knowing the package limits the search massively. In this case it's a odd-ball size that comes out as a SOD128, slightly larger than the common SOD-123, and smaller than SMA/SMB.

From there it seems that NXP used the package first, and then more recently companies like Rohm have too (it's not listed as one of their packages until after 2013). This sort of fits as the diode itself looks like it was made with a modern process with the very crisp markings.

Then it's just a case of looking for diodes in SOD128 packages. Rohm has a stock image they use for their website for this package which shows three bards for the cathode, so I focussed on them.

A random stroke of luck showed this in a datasheet for one of their more recent diodes in this package:

Package Markings

That looks oddly familiar - three lines for the cathode, two numbers for the part marking, and then two small regions which indicate the manufacturing date (the dotty codes in your image).

From there I was sure the manufacturer was correct. So we have type of component (diode), package (PMDTM/SOD128) and manufacturer (Rohm). From there it's just brute force and ignorance until we come across RB055LAM-60, which has the same package, and a marking of 96. Jackpot.

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  • \$\begingroup\$ Dear Tom Thanks a Lot. I hope to compensate for your valuable help.🌹 \$\endgroup\$ – Vahid Naim Nov 7 '20 at 13:03
  • \$\begingroup\$ @VahidNaim mark this as the answer \$\endgroup\$ – BeB00 Nov 7 '20 at 22:00

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