Question

15 Q1. (a) Fill up the following table and briefly explain the circuit operation of each case. The circuit parameters are: V+ = 12 V, V- = -12 V, Rc = 10 K, la = 1 mA. Qi (on/off) Q (on/off) V. (V) va (v) V2 (V) Type VB1 (V) VB2 (V) Case-1010 Case-II - 1 0 Case-11 1 2 S Show that the differential output voltage of a differential amplifier is Vo = -1 Rc C ). where Va is the differential voltage, Vr is the thermal voltage. Also draw Vo as a function of V, and indicate the linear regime. (hints: first derive the equation for la and le as a function of lol

Answer 1

ove Ia ure from figure Iest I Eg Ia Noi = Vcc-ic, RC Ncq = Vec - ice Rc Apply kul we get VBE, -VBE= vode Now consider that Iei = Igo e vocilvo - 0 IE2= Ico e Veglur - Using compondo_dividendo rule vidlvr. It - Icg video

- vidlvr. Io = e XVI, allo-ica ] evidla ich-ico=& Iq e evid/ VITI !!! No= Nci-vce No=-{"c_ica] RC so to becomes. [Vo== alq Rc e I - Nidder. VT if vid si =) Vo = -XJq Rc if Vid <<T * VE & Ia Re a > Vid 1/2 th 2012] -&Ia Red 2 [2/2 2/2] we know that en et e Lete 12 so we get to as ( No = -X Ja RC Tant 7 QVT

we know that Tambra = 2-2 +22%-17*+--- if vid sal - so we get to is I Vo=u& Iq Rc void QV QVT Call Type I Bil VBQ al al recryl vc (W) Vca(w) | case- s olo ON/ON -0.7v fr 7V Cause in tloloFF ON I-DoZU 12V QV tordal 12 OFF ON 1.3V 12V av Case(i) VBI = Or, VB2 = OV Both non transistors will be on. so the current will flow through each transistor is Osma Рpr: hp #ис Гоор ? - V131 +VBE, + Ve = 0 Ve= VBI-VBEL VE = 0-0.7V 1 Na = -0.#vo s -Vec + Ica Rc + veq = 0 Veq=vec-Ica Re Veq = 19-(0.5X17J x 10x so V2 = 12-5=7V

cesdii & VBI =-IV, V862 = OV Q, - OFF, Q-ON ! So Icra OA IcQ = IMA V VcQ = NCC-I C2 Red Ve2= 12-10% 10x jo? = av ou a + Vieg + Voeg tvezo ? Ve =-VB6p+ V182 The = -0.7V) . Case(3) VB1 = IV, VBQ=2V., Q-OFF, 02QN . So veq = 2v. -VBaF Visca + Ve zo Vez 182-Voeg = 2-007 ī Ve=103 Vision 3