P-Channel E-Type MOSFET Switch Gate to Source Voltage Positive and Negative

P-Channel E-Type MOSFET Switch Gate to Source Voltage Positive and Negative:

 Three modes of Operating Region of Metal Oxide Semiconductor Field Effect Transistor [ MOSFET ] are:

1. Linear Region (Ohmic)
2. Saturation Region
3. Cut-off Region

1- Linear Region Characteristics:

• In 'Linear Ohmic Region' , the transistor operate as an 'Variable Resistor', whose value is determined by the Gate Voltage, [ V_GS ]. 
• The 'Gate to Source' Voltage [ V_GS ] is greater than the Threshold Voltage [ V_TH ]. i.e [ V_GS > V_TH ].  
• The 'Drain to Source' Voltage [ V_DS ] is greater than 'Gate to Source' Voltage [ V_GS ] i.e [ V_DS > V_GS ]

2- Saturation Region Characteristics:

• ​​In 'Saturation' region, the transistor operates as an 'Closed Switch'.
• The MOSFET is in its constant current region.
• The MOSFET is switched 'Fully-ON'.
• The 'Gate' Electrode is Connected to Supply Voltage [ V_DD ].
• The 'Gate-Source' Voltage [ V_GS ] is greater than Threshold Voltage [ V_TH ] i.e [ VGS > V_TH ].
• Maximum 'Drain' Current [ I_D ] flows, i.e [ I_D = V_DD/R_L ]
• This condition of transistor is act as a 'Fully-ON' and this is 'Saturation Region'.
• 'Drain to Source' Voltage [ VDS ] is approximately equal to Zero ideally. i.e [ VDS = 0V ].
• 'Drain to Source' Channel Resistance [ R_DS(on) ] is Minimum. i.e [ RDS < 0.1 Ohms ].
• The MOSFET acts as a Closed Circuit. 

​3- Cut-Off Region Characteristics:

• ​​In 'Cut-off' region, the transistor operates as an 'Open Switch'. 
• The MOSFET is switched 'Fully-OFF'.
• The 'Gate' Electrode is Grounded to 'Zero' Voltage. [ 0V ].
• The 'Gate-Source' Voltage [ V_GS ] is less than Threshold Voltage [ V_TH ] i.e [ VGS < V_TH ].
• No 'Drain' Current [ I_D ] flows, i.e [ I_D = 0A ].
• This condition of transistor is act as a 'Fully-OFF' and this is 'Cut-OFF Region'.
• 'Drain to Source' Voltage [ VDS ] is approximately equal to Supply Voltage. i.e [ VDS = V_DD ].
• 'Drain to Source' Channel Resistance [ R_DS(on) ] is Minimum. i.e [RDS < 0.1 Ohms ].
• The MOSFET acts as a open Circuit.

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