How the voltage current characteristics are affected because of channel length modulation effect?
The resistance of the channel is inversely proportional to its width-to-length ratio; reducing the length leads to decreased resistance and hence higher current flow. Thus, channel-length modulation means that the saturation-region drain current will increase slightly as the drain-to-source voltage increases.
What is the impact of channel length modulation?
Channel length modulation (CLM) is an effect in field effect transistors, a shortening of the length of the inverted channel region with increase in drain bias for large drain biases. The result of CLM is an increase in current with drain bias and a reduction of output resistance.
Why does the threshold voltage decreases with the channel length?
The threshold voltage is lowered due length decrease to a submicrometer size. Also the width shrinkage causes change in the threshold voltage. This is due to charge sharing phenomenon and induced barrier lowering.
How gate source voltage affects the drain current in Mosfet?
Figure 1.7 shows a gate charge circuit and a gate charge waveform. When a MOSFET is connected to an inductive load, it affects the reverse recovery current of the diode in parallel to the MOSFET as well as the MOSFET gate voltage. As the gate voltage increases, the drain current increases.
How does channel length modulation affect drain current?
Thus, channel-length modulation means that the saturation-region drain current will increase slightly as the drain-to-source voltage increases. So we need to modify the saturation-region drain-current expression to account for channel-length modulation.
What causes channel length modulation in a MOSFET?
Channel length modulation. Channel length modulation in a MOSFET is caused by the increase of the depletion layer width at the drain as the drain voltage is increased. This leads to a shorter channel length and an increased drain current.
How is channel length modulation used in saturation?
A commonly used expression for MOSFET drain current in saturation with channel length modulation is the following: FIGURE 3.14. where λ is known as the channel length modulation factor expressed as: and Eo is the magnitude of the electric field at the pinch-off point.
Is the output resistance infinite without channel length modulation?
Without channel-length modulation (for λ = 0), the output resistance is infinite. The channel-length modulation parameter usually is taken to be inversely proportional to MOSFET channel length L, as shown in the last form above for rO: where VE is a fitting parameter, although it is similar in concept to the Early Voltage for BJTs.