For the CMOS circuit below, what is the voltage labeled V0? -5 V -4.1

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For the CMOS circuit below, what is the voltage labeled V0? -5 V -4.1 V -0.9 V +0.9 V +4.1 V +5 V Vtn = |Vtp| = 0.9 V

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For the CMOS circuit below, what is the voltage labeled V0? -5 V -4.1 V -0.9 V +0.9 V +4.1 V +5 V Vtn = |Vtp| = 0.9 V

Explanation & Steps

The given circuit is a CMOS inverter, which has one NMOS (n-type metal-oxide-semiconductor) transistor and one PMOS (n-type metal-oxide-semiconductor) transistor. In the given question, output voltage need to be determined at a certain input voltage applied to CMOS inverter. The threshold voltage of these transistors is denoted as Vtn for NMOS and Vtp for PMOS. Use these steps to determine output voltage for input voltage of 5 V.

Step (1): Determine mode of operation of both NMOS and PMOS transistor by calculating VGS, VGS – Vtn and VDS. If mode of operation can’t be determined then it need to be assumed out of triode or saturation region.

Step (2): Solve drain current equations of NMOS and PMOS transistor.

Step (3): Verify mode of operation assumed in step (1). If it is verified then output voltage calculated in step (2) will be the value of output voltage, Otherwise change mode of operation and repeat above steps.