Summary of Operation

Let us summarize the discussion so far:

  1. To understand the operation of the MOSFET device, the understanding of the MOS capacitor is very important

  2. The MOS Capacitor operation depends on the polarity of the voltage applied between the Body and the Gate.

  3. The MOSFET operates in three modes or regions of operation, depending on the polarity of the applied voltage and also on the magnitude of the applied voltage.

  4. In our discussion here we have taken an N type MOS capacitor. The same discussion is equally valid for the P type MOS capacitor by reversing the applied bias voltage.

Voltage Applied

Type of Operation

VGB < 0, Gate voltage is negative

Accumulation of Holes - Accumulation Mode

0< VGB< VT

Depletion of Holes - Depletion Mode


Inversion Layer - Inverted Mode