I am designing a PCB that senses basic NTC values and converts it into digital format. The problem is the entire PCB is above a magnet(about 70mT at the board) that is moving. Hence i want to know what happens to components when in such fields? I expect a diode to deplete in its bias characteristics as the electron or holes should experience a Lorentz force . But is the powerful enough to make my diode not operational ?

I am also curious what might happen to op-amps and BJT. Is it possible i can simulate this in LTspice or something ?

Note: i do not have room to shield or move away. Lets say there are given constrains.


70 mT will have no impact on your circuit unless you send huge levels of current. Measuring mT requires specific elements to have measurable results and is in general not detected at all by regular integrated circuits.

You may want to protect against inductive coupling that will not happen in the circuit but in the lines that connect your circuit to the external world, in particular if your field is varying rapidly.

  • \$\begingroup\$ Indeed i have some measures in place for the interconnects (lines as you called them). My field is varrying and so i have made the interconnects twisted. Now i am just worried about other components like Diodes and Op-amps. Its becomming hard to predict what will happen to these solid state devices \$\endgroup\$
    – vittal rao
    Feb 9 '15 at 9:45
  • \$\begingroup\$ Why don't you just try it and see what happens, since that's where you're going anyway? \$\endgroup\$
    – EM Fields
    Mar 10 '15 at 11:29

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