mosfet Reverse polarity protection

Posted on Feb 4, 2014

When the reverse voltage is applied that is say 10V to Source and the drain is grounded. So now the Vgs is -10V which is well above the threshold and is good enough to keep the MOS in saturation region. So it is conducting in the opposite direction also now. Please correct me if i have saidsomething which is incorrect. Durgaprasad Mar 21 `13 at 4:47 Look back at the schematic.

mosfet Reverse polarity protection
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If the polarity is reversed, the diode will not conduct. No current flows, so the gate and source will be at 10V. $V_{gs}=10V-10V=0V$. The transistor does not turn on. Matt Young Mar 21 `13 at 4:53 I got your point with the diode. But when the source is at 10V and gate is grounded and drain is also grounded. Then the Vgs is = -10V. Right So I am thinking that the MOS should conduct (Usual configuration of PMOS), though the body diode is reverse biased. Durgaprasad Mar 21 `13 at 5:12

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