Question

3.2. A differential amplifier resembling that below uses I = 200LA, Rç = 10k and Vcc = 3V. Assume very large. is What is the differential gain vva achieved for outputs taken differentially? What if single-ended outputs are taken from either collector? What is the upper limit of the common-mode input voltage for which operation keeps both transistors in the active mode? (c) Vec Rc Rc Q2 O D Question 2 1 pts Consider practice question 3.2. The bias current I is changed to 0.17 mA. Find the differential gain in part (a). Question 3 1 pts Consider practice question 3.2 with the original value of bias current. The resistor is changed to 7.4 kilo-ohms. What is the maximum common-mode input voltage in part (c)?

Answer 1

Gaiun diagrame Vec Re lok Vec 3V Re t ed The AC fatuws Analysis Con ba clene as Rc Va Rc R fe For large value of p 2S mV t00x10A Vi e 2 m Re 4 200MA Fm Re d iDouA Than dipfasential gain Aode looxiD 25XLDS Then m fe Va Add Fm Re ..3 4XLD x --40

b) Valtage gainf ig le naleal output Analge Fiem AC enew, asot - m Re a (W Also o m Rc eol alene as 02 output, then ba uigle enalod is gauol to utput alene, aue take Than alne gain o Adlt i,Adalt Add 40 RO CAdel Diffesent ial Mode Gan) Max put Commen Mode Valtoge Vic Cmax)VBE +Voi or Vo) 2 VBE + Vac- T R 2 O -200XLD x bxLD z6t 3- i 2 V Qus tun g) hemyel wRen O.I mA Te Ic 8.SXLO A

Them fe Te 8-SXLD 3.4xD 2SXLD Tham. Dtuntial Gan. Adel m Re 2 3 2-3.4 xLD x Dx ID 34 Questin (3) Max Cemmen mode Tmput Valtuge Re f-4K Cvei Vie Cymax) VBE + e Voz VBE t Vec Rc 00XLD 3- 4x LD 2 x 2 O t 3- 04 2.96V 2