When VGS < VGS(th) in an N-channel EMOSFET,
Question 4 options:
a) the resistance RDS is at its minimum
b) a channel is induced between the Drain and the Source
c) the device operates in the saturation region
d) drain current is zero
b) a channel is induced between the Drain and the Source
To achieve a logic low at the output of a CMOS logic gate, it is required that the pull-down network __A__ for all input combinations; and the pull-up network __B__.
Question 6 options:
a) A=opens, B=conducts
b) A=conducts, B=opens
c) A=conducts, B=conducts
d) A=opens, B=opens
c) A=conducts, B=conducts
What are some of the ways to reduce dynamic power in CMOS switching circuits. Select all that apply.
Question 8 options:
a) Disable the clock for inactive circuits
b) Reduce switching frequency
c) Increase supply voltage
d) Reduce circuit capacitance
a) Disable the clock for inactive circuits
b) Reduce switching frequency
d) Reduce circuit capacitance
The correct answer is c) the device operates in the saturation region.
In an N-channel EMOSFET (Enhancement-Mode Metal-Oxide-Semiconductor Field-Effect Transistor), when VGS (Gate-to-Source Voltage) is less than the threshold voltage (VGS(th)), the device operates in the saturation region. In this region, a conducting channel is already induced between the Drain and the Source regions, and the device allows a significant amount of drain current to flow. The resistance RDS (Drain-to-Source Resistance) may not be at its minimum in this scenario. Therefore, options a) and d) are not correct.
To answer this question, we need to understand the behavior of an N-channel Enhancement-Mode Metal-Oxide-Semiconductor Field-Effect Transistor (EMOSFET) when the gate-to-source voltage (VGS) is smaller than the threshold voltage (VGS(th)).
Option (b) correctly states that a channel is induced between the Drain and the Source.
Explanation: In an N-channel EMOSFET, when the VGS is smaller than the VGS(th), the gate voltage is lower than the threshold voltage required to form a conducting channel between the source and drain. As a result, the transistor remains in the "off" state, and no current flows from the source to the drain.
Option (a) is not correct. The resistance RDS (drain-source resistance) is typically smaller when the transistor is fully turned on (VGS > VGS(th)) than when it is in the "off" state.
Option (c) is not correct. The device operates in the saturation region when VGS is greater than VGS(th) and a conducting channel is formed between the source and drain.
Option (d) is not correct. The drain current is typically zero when VGS is smaller than VGS(th) because the transistor is turned off and no channel is induced between the source and drain.
So, the correct answer to this question is (b) a channel is induced between the Drain and the Source.