Question

ANSWER ALL QUESTIONS: 0-1. Study the circuit diagram given in Figurel and answer the following questions. (1.5 marks) i.) When the square wave voltage is + 5V, the transistor will be in which region? c) Saturation ii.) When the square wave voltage is OV, the transistor will be in which region? a) Cutoff region b) Saturation c) Active region iii.) When transistor operates in Saturation region, what are the values of Vce, and Ic? iv.) When transistor operates in Cutoff region, what are the values of Vce, and Ic? Figure 1 Vec - 10 volts RCS1.OK Q-2. Study the following FET circuit given in Figure 2 and answer the following questions: (3.5 marks) i) Which kind of FET was used in the circuit? a) N-Channel JFET b) P-Channel JFET c) N- channel D-MOSFET ii) Calculate the drain to source current (ID) for VGs - 3.8V using the following transfer characteristics formula 1= Ipss1 - (Vcs/Vp) assuming Iss= 19 mA. iii) Write the names of three operating regions of JFET. Figure 2 Up- - iv) Differentiate Bipolar Junction Transistor (BJT) to Field Effect Transistor (FET). v) Draw the symbol of the P-Channel JFET. vi) Draw the symbol of the N-channel Depletion MOSFET.

Answer 1

Solution 00% O BTT is no For +51-7 BJT on and in Saturation Region Note: in figure to BJT is used as switch option © Saturation 7 Shost ckt @ for ov -> BJT will be in cutt off Region - option @ cutloff open ckt © BJT in Saturation 7 Fully on Veezal ideally) Shest cht * Ica rcc = - loma Fe=loma] Note: Practically rce= 0-2 Volt » Iez vec-02, 9-8mA 6 BJT in culoff open cht IK . (VCE = Vec) and Ic= oma

Boleto opten @ Channel TPET © given Ipss = 19mA and VGS = -3487 From Peguese 2. Ype-5V of ID= Loss (1- VGs ² E 196160 [1-)] - pol mA 170=lolma © The Three operating regions of TEET GR 0 ohmic / Limeas Region © Saturation Region © cut off Region

In Difference Between BJT and FET - BJT I FEET o Bipolar Derice : Cussent 0 Unipolar Device: Cussent due to both eletrong and I only due to electors of holes only due to holes © Current Contsolled voltage controlled = BIB Lo=9083 (1-V *2= f(IB) 720 = f(Vgs) Ic deperes upon Z8 Jo depends upon voltage (VGS) @ Low Input Impedance @vesy high Input Impelline @ thermal sun-hujay No Thermal hem away thukes place 6 Big dize 6 mall deze © Trans conductance is 16 Trans conductance of FET high is lower than BJT Ø Applications: Ø Applications: switch - ohmic and switch :- Satisation and e cult off Amplifies: Active e Region Aplifies : Saturation Region

P-Channel TFET: D at Channel Depletion Mosfet: SS