Question

An NMOS transistor has Vt0 = 0.8 V, 2 φf = 0.7 V, and γ = 0.4 V1/2. Find Vt when VSB = 3 V.

(a) 0.12 V

(b) 1.23 V

(c) 2.34 V

(d) 3.45 V

The question was posed to me during an internship interview.

My doubt is from The Body Effect topic in division MOS Field Effect Transistors (MOSFETs) of Electronic Devices & Circuits

Answer 1

Right answer is (b) 1.23 V

For explanation: Vt = Vt0 + k[√(Vsb + 2φf) – √2φf]. use this expression to obtain the desired result.