What is DESAT protection?
The VCE(sat) detection (DESAT detection) circuit which detects the rise of the collector or drain voltage (VCE) when an over-current flows into the power semiconductor switch device (hereinafter referred to ‘power device’) driven by the gate driver by causes, such as a short circuit of load, makes the power device turn …
How to protect MOSFET from short circuit?
If you have an application in which a MOSFET is already used to switch a load, it is relatively easy to add short-circuit or overload protection. Here we make use of the internal resistance RDS(ON), which produces a voltage drop that depends on the amount of current flowing through the MOSFET.
How does desaturation protection work on an IGBT?
Below is the basic circuit for the IGBT control with desaturation protection, using a microcontroller is a lot more concise than using logic circuits. As you can see when the IGBT is off there will be 100V across it, there is a diode used for detection, one side has a 15V source, the other 100V, therefore no current flows.
When does an IGBT and MOSFET over saturate?
IGBT and MOSFET Desaturation Protection When an IGBT or MOSFET are fully “on” they are known to be saturated, when they exceed their maximum current ratings they are known to “over saturate” which will eventually cause failure of the device.
When to add protection to a DC switch?
In all cases, we routinely recommend that protection be placed local to the inductive load being switched. For DC inductive loads, this usually takes the form of an added reverse-biased shunt diode placed right across the load terminals. We make this recommendation even when our switches may already incorporate similar protection inside the device.
Can a reverse spike destroy a MOSFET switch?
For a solid-state mosfet switch, the high voltage reverse spike can destroy the switch, although most mosfets actually include a source-drain diode to shunt this spike at the switch.