1
GATE ECE 2017 Set 2
+2
-0.6
Two n-channel MOSFETs, T1 and T2, are identical in all respects except that the width of T2 is double of T1. Both the transistor are biased in the saturation region of operation, but the gate overdrive voltage (VGS - VTH) of T2 is double that of T1, where VGS and VTH are the gate-to-source voltage and threshold voltage of the transistors, respectively. If the drain current and transconductance of T1 are ID1 and gm1 respectively ; the corresponding values of these two parameters for T2 are
A
8ID1 and 2gm1
B
8ID1 and 4gm1
C
4ID1 and 4gm1
D
4ID1 and 2gm1
2
GATE ECE 2017 Set 2
+2
-0.6
Assuming that transistor M1 and M2 are identical and have a threshold voltage of 1V, the state of transistors M1 and M2 are respectively
A
Saturation, Saturation
B
Linear, Linear
C
Linear, Saturation
D
Saturation, Linear
3
GATE ECE 2017 Set 2
Numerical
+2
-0
A MOS capacitor is fabricated on p-type Si (silicon) where the metal work function is 4.1 eV and electron affinity of Si is 4.0 eV, Ec - EF = 0.9 eV; where Ec and EF are conduction band minimum and the Fermi energy levels of Si, respectively. Oxide$${\varepsilon _r} = \,\,3.9,\,\,\,{\varepsilon _{0\,\,}}=\,8.85 \times {10^{ - 14}}$$ F/cm, oxide thickness $${t_{ox}} = 0.1\,\mu m$$ and electronic charge q = $$1.6 \times {10^{ - 19}}$$ C. If the measured flat band voltage of the capacitor is –1V, then the magnitude of the fixed charge at the oxide semiconductor interface, in nC/cm2, is __________.
4
GATE ECE 2016 Set 2
Numerical
+2
-0
Consider a long-channel NMOS transistor with source and body connected together. Assume that the electron mobility is independent of VGS and VDS. Given,
gm = 0.5$$\mu {\rm A}/V$$ for VDS = 50 m V and VGS = 2V,
gd = $$8\mu {\rm A}/V$$ for VGS = 2 V and VDS = 0 V,
Where gm =$${{\partial {{\rm I}_D}} \over {\partial {V_{GS}}}}\,\,and\,\,{g_d}\,\, = \,{{\partial {{\rm I}_D}} \over {\partial {V_{DS}}}}$$

The threshold voltage (in volts) of the transistor is