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What does body diode do in MOSFET?
While the body diode is in reverse recovery, its drain-source voltage rises. This behavior can cause a false turn-on of the internal parasitic NPN bipolar transistor, destroying the MOSFET. There is really only one disadvantage of having no body diode: higher reverse voltage drop.
How body diode is formed in MOSFET what are its consequences?
As a consequence of the MOSFET structure, the body diode is formed by the pn junction between the source and drain, and is also called a parasitic diode or an internal diode. The performance of the body diode is one important parameter of the MOSFET, and is important when using the MOSFET in an application.
What is the body diode of the power MOSFET?
Unlike virtually every other active device, the power MOSFET is unusual in that its schematic symbol includes a parasitic device – the body diode. The body diode is intrinsic to the device’s structure.
How is the bipolar transistor used in a MOSFET?
Discreet power MOSFETs also feature a parasitic bipolar transistor, but the metallization connecting the source and body regions — also an explicit feature of the schematic symbol — shorts the base-emitter junction. This prevents the bipolar device from turning on under all but the most extreme conditions.
Can a MOSFET be used for bidirectional switching?
If the source voltage is always lower than the drain voltage, the diode stays off, and everything works as expected. This means you can’t (easily) use a MOSFET for switching a bidirectional signal. Discrete MOSFETs are almost always used for low-side switching, so this limitation isn’t a big deal in practice.
How is the Schottky diode related to the body diode?
A Schottky diode connected in parallel to the body diode will conduct with a lower forward voltage, preventing the body PN junction from becoming forward biased. The Schottky diode is a majority-carrier device and exhibits no recombination.