1. Home
  2. Electronics Design
  3. Wrong packaged diode

Wrong packaged diode

Hello all,

A board we produce has a battery that power a static RAM through a diode. This is a SMD package, maybe a SMA, but can't say for sure right now.

We have had a few problems with the battery circuit, that I know have been solved changing the diode.

I have seen only one of those myself, and it looks like the diode is packaged the other way round i.e. the package strip pointing to the anode instead of pointing to the cathode.

Is this at all possible ? Am I doing something wrong ? Any similar experiences around ? As the board is produced in China, I would tend to think it is a counterfeit diode.

Thank you in advance.

Josep

Reply to
djj08230
Loading thread data ...

More info needed. Many diodw packages can be obtained with alternate pin-out or polarity, at a premium.

Some diodes have functional characteristics in the forward and reverse direction, which might require their use in what looks like an inverted mode.

RL

Reply to
legg

Thank you. I've got the info now.(monday morning here)

The diode is MURS105T3G from On Semiconductors in an SMB package.

formatting link

Probably not the best bit, but to me, this is an odd behaviour. Testing the diode with a multimeter looks like the package is reversed. Do they hand-assembly these tiny diodes ? (!!!)

Josep

Reply to
djj08230

There is no point in producing an 'axial' two-lead device with an alternate pin-out. Alternate pinouts only occur if a mechanical reversal is impractical or impossible to achieve as shipped.

Check part out-of-circuit. Forward voltage drop will be evident if positive conventional current is forced into anode to return via cathode. If cathode band (schematic symbol points to it) is incorrectly impressed, you've got a load of rubbish.

RL

Reply to
legg

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.