GATE EC 2018 Set 1 Q43 — BJT and MOSFET Amplifiers

In the circuit shown below, the $(W/L)$ value for $M_{2}$ is twice that for $M_{1}$. The two $\text{nMOS}$ transistors are otherwise identical. The threshold voltage $V_{T}$ for both transistors is $1.0\:V$. Note that $V_{GS}$ for $M_{2}$ must be $> 1.0\:V$.

Current through the $\text{nMOS}$ transistors can be modeled as

• $I_{DS}=\mu C_{ox}\left ( \dfrac{W}{L} \right )\left( \left ( V_{GS} -V_{T}\right) V_{DS}-\dfrac{1} {2}V^{2}_{DS}\right )\:\:\:\text{for}\:\:V_{DS} \leq V_{GS}-V_{T}$
• $I_{DS}=\mu C_{ox}\left ( \dfrac{W}{L} \right )(V_{GS}-V_{T})^{2}/2\:\:\:\:\:\text{for}\:\:V_{DS} \geq V_{GS}-V_{T}$

The voltage (in volts, accurate to two decimal places) at $V_{x}$ is ________.