question about P-MOSFET

[ilikebbs]

when P-MOSFET is off(Vgs=0), is the voltage at D equal to the voltage at S because of the parasitical diode?

and the leakage current will be uA level.

Is my understanding right?

 

[Audioguru]

When a Mosfet is turned on, its Drain voltage is near its Source voltage. When it is turned off then the circuit's resistors and power supply determine the voltages.

In most circuits, the parasitic diode in a Mosfet never conducts.

 

[midgariano]

When VGS = 0, the transistor is off, it means that the current dosen't flow across the transistor, for, but it dosen't mean that the voltage VDS is equal to cero (VDS=0), because all the elements conected to the drain an the source, fo example ground or a resistor and Vdd, define the voltaje in this two terminals of the transistor; and, the parasitic diode of the transistor in the cases dosen't conduts.

 

[octocreation]

Hi,

well if u r talking about PMOS, we generally refer to VSG and not VGS.......

regds,
Anup

 

[A.Anand Srinivasan]

the voltages may be different...

Which leakage are u talking about???

 

[santom]

@Anand, Can you please give a clear explanation about this question as usual please..

Thank u all

Regards
santom

 

[A.Anand Srinivasan]

when the PMOS is off( condition given) there is no connection between the source and the drain and so the drain and source can be kept at diff voltages provided that we take care that the voltage between drain and source doesn't reach the point where punchthrough occurs...

 

[santom]

Thanks @Anand..