REVERSE RECOVERY TIME

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Created by
Ki M

Cards (10)

  • reverse recovery time
    • This is a time measure related to how quickly a diode can switch from allowing current to flow (conducting) to blocking current (non-conducting) when the direction of the applied voltage changes.
  • diode basics
    • Diodes are electronic components that allow current to flow in one direction (forward-bias) and block it in the opposite direction (reverse-bias).
  • forward bias condition
    • When the diode is in a forward-bias state, electrons from the n-type side move to the p-type side, and holes (positive charges) from the p-type side move to the n-type side. This movement allows current to flow through the diode.
  • reverse bias condition
    • When the voltage is reversed (reverse-bias), we ideally want the diode to instantly stop conducting. However, it doesn't happen immediately due to the presence of minority carriers (electrons in the p-type and holes in the n-type) that were built up during the forward-bias state.
  • the shorter the minority carrier lifetime, the faster the reverse recovery time.
  • the longer the minority carrier lifetime, the slower the reverse recovery time.
  • storage time
    • This is the time it takes for the diode to get rid of these minority carriers. During this period, the diode still allows some current to flow in the reverse direction.
  • transition interval
    • After the storage time, the diode starts transitioning to its non-conducting state. This is the period during which the current decreases to the level associated with the non-conducting state.
    • In applications where diodes need to switch on and off rapidly (high-speed switching), having a short reverse recovery time is crucial. Most diodes used for these purposes have very short trr, ranging from a few nanoseconds to a microsecond, with some specialized diodes having even shorter times measured in picoseconds.
    • The total time for the diode to switch from conducting to fully non-conducting is the sum of the storage time (ts) and the transition interval (tt). Hence, trr = ts + tt.