Help identifying magnetic sensor

D

Diver300

Well-Known Member
Most Helpful Member

This was in a camshaft sensor in a BMW. I know there's no hope of repairing the sensor as it was potted and I did a lot of damage getting it out, but it had been electrically damaged first.

There is a magnet behind this in the sensor.

I've looked on the Infineon website and I can't find anything even in this package. Can anyone identify it?
 
rjenkinsgb said:
These look suspiciously like they may be the ones, with that dual centre pin?

Click to expand...
I found a whole load with the dual centre pin, but the marking doesn't seem to line up.

The one that I have seems to have about 100 nF from the power supply to ground and 2 nF from the output to ground. The capacitor is not the part that got sawn off, so that is still intact.
 
ZipZapOuch said:
Further proof that even a used BMW at a really good price isn't a good deal.
Click to expand...
Well to be fair this sensor has never actually been on a BMW, or any other car for that matter.

What disappointed and confused me is that smoke came out when I had connected it to a 12 V supply. I probably connected it wrong, but just 12 V shouldn't have damaged it.
 
With all the other similar parts I've found while searching, the last two digits of the part number have been the first two of the SMD package code.

It seems a TLE4931 exists - but possibly a custom part for a specific manufacturer, as information is very patchy & no data sheet links work??
Could that be it?
 
I think you are correct. I had seen that other parts in that package are labelled with the last two digits, but I couldn't find anything on the Infineon website about ones ending -31.
 
Why not?, you stick 12V on a circuit connection that isn't rated for 12V, and probably isn't a power input anyway, then you're very likely to blow things. I don't see how you could think otherwise?.
 
Nigel Goodwin said:
Why not?, you stick 12V on a circuit connection that isn't rated for 12V, and probably isn't a power input anyway, then you're very likely to blow things. I don't see how you could think otherwise?.
Click to expand...
A lot of automotive electronic modules are protected against incorrect connections, and most manufacturers work to standards that say that modules should be tolerant of 12 V, so I had expected that this transducer would be the same.

As an example, here are the maximum ratings of a CAN transducer:-


The CANbus connections CANH and CANL (for some reason referred to by their pin numbers in the next line) are rated to survive connection to the power supply, even on 24 V vehicles. The Vdd and logic-level pins would not be connected to the module pins.

Many of the Infineon Hall sensor ICs are similarly protected, with reverse polarity protection and output current limit, so it's not very easy to blow them with an incorrect connection.
 
Diver300 said:
A lot of automotive electronic modules are protected against incorrect connections, and most manufacturers work to standards that say that modules should be tolerant of 12 V, so I had expected that this transducer would be the same.
Click to expand...

That's wishful thinking - sticking 12V where it's not supposed to go isn't likely to be protected against, why should it be?, they connect via polarised plugs so can't be connected wrongly. If somebody sticks 12V up a random pin, then they are asking for whatever they get

But without a schematic we're just guessing what's happened.
 
Nigel Goodwin said:
why should it be?, they connect via polarised plugs so can't be connected wrongly
Click to expand...
There is lots of protection against incorrect connection. The polarisation of plugs is one protection, and electronic protection is another.

A lot of devices like routers have the power coming in through a diode.

A lot of effort goes into protecting vehicle electronics. The standard tests involve reverse polarity and lost of ground or supply when operating. The manufacturers don't want to pay warranty costs if one of their technicians plugs in something wrong, or a fault on a harness shorts two wires.
 

No mention of sticking 12V where you shouldn't

You've blown it, obviously there's no protection.
 
Most devices limit the voltage to any input to 0.7v above the supply current. If, as you said above. If you put 12v into an input when no supply voltage was present, you'd exceed the Absolute Limit by 11.3 volts.

If you connected the 12v to an output, then there is no telling what damage is done. Most outputs are limited to 30mA sink or source and, with current applied, it is likely dead. Oh, the smoke and crack confirm.
 
You must log in or register to reply here.

Similar threads

J
  • Question
Help Identifying component
Replies
3
Views
1K
Diver300
D
K
Help identifying this
Replies
4
Views
817
Kaltal
K
S
  • Solved
Need help identifying a connector
Replies
9
Views
2K
rjenkinsgb
H
  • Question
Help identifying components.
Replies
13
Views
2K
Henkel
H
P
  • Solved
Need help identifying PCB component
Replies
8
Views
1K
Diver300
D
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…