Breakdown Voltage

Discussion in 'General Electronics Chat' started by moska2004, Nov 19, 2010.

  1. moska2004

    Thread Starter New Member

    Jul 16, 2010
    What is happening if I connect two transistor in series having different breakdown voltages ?

    VCE1=30V, VCE2=20V and supply voltage 25V. Both transistors switched off.
  2. JDT

    Well-Known Member

    Feb 12, 2009
    When both transistors are switched off they will still conduct some leakage current so is is difficult to say how the voltage will be shared across the transistors. To be sure, do not apply more than 20V (the lowest value).

    It is possible to use a number of devices in series to control a high voltage but they

    • will all be the same type
    • will have extra devices (a resistor chain) to ensure that the off-state voltage is equally shared.
    Basically not a good idea except in special situations.