Fast Recovery High Voltage Diode Assemblies
MOSFET switches and free-wheeling diodes: In general the forward voltage of an intrinsic MOSFET switch diode is lower than the forward voltage of an external fast free-wheeling diode. In order to keep the reverse currents safely away from the intrinsic diodes it is neccessary to connect a so called “Blocking Diode” in series to a MOSFET switch. Therefore we always suggest to use this additional blocking diode when MOSFET switches shall be protectted by fast free-wheeling diodes. The blocking diode must have at least the peak current capability of the switch. The hold-off voltage is uncritical and must only be higher than the forward voltage difference between intrinsic diode and free-wheeling diode. The difference is usually some ten volts, in extreme cases some hundred volts (large MOSFET stacks and extremely high peak currents). Sufficient blocking diodes are available as single part component or as an integrated part component of a BEHLKE FDA diode (integrated blocking diode, option IBD and IBD-C).
- for HTS switches in combination with inductive load
- Soft recovery characteristics
- High peak current capability
- Very low inductance, short recovery time