Question

im currently doing an assignment where i must design a two stage bipolar transistor, i just need the calculations and values for each component and then i can run simulated experiments and complete my work

here is the schematic

VCC RC1 R1 C5 C3 Outi Transistor2 BC846B V1DC + In B1 Transistor 15 c4 E2 Out BC846B V2AC E1 SINE(O 1 1k) RE2 Rload R2 RE1 C2 1Meg op

the transistor used is the BC846B

the supply voltage is 15 v

the collector currents 1 (ICq1) = 1.5mA

the collector current 2 (ICq2) = 7.5 mA

output voltage swing= max

frequency response = 50- 20 khz

i must calculate the required specifications for each component

i have so far calculated

VE1= 3

VE2= 8.4v

RE1 at 2k ohms VE1/ICQ1

RC1 at 4k ohms VRC1/ICQ1

RE2 = 1120k ohms VE2/ICQ2

Answer 1

Vcc - Isu Ic (91) = 1.5mA Ic (Q2) = 7.5mA VEI = 3 V Ver 8.4 V REI zka REL = 1.12 km between Vec and VE, Vor = half waye half way between 150 and 3v 15 - 3 3 + =) 2 VCI - 9V lcc Vc .. RG : Ical Ri = 4RR 15-9 1.5 Í B, max Ici ß 1.5 ma 2o2 V BI VE, toob 3 +0.6= 3.60 vec- UBI FB, RI 10 IBI = II 15 3.6 1,5 lox. R 203 152ka RI I, — Ibi R2 = Current thro thorough g I Bimax VB, R2 I IB, max 3.6 9x1,5 mA R2 200 Rz 53.33kh - Xc - ~ REI 2 t f Ca = min operating frequency = 50Hz it са 27 X 50 X 2.8103 C2 1.59 MF 2 ok 42 a Relat f Xc 11 25 f (3 C3 270 x 20 x 103 x 2X103 3.978 nF C3 Cica, cs to have low impedance at 5042 to be mi. low Let's choose 2a fc 473MF C = Cy=CG

Vcc RC1 C3 R1 4k 152k 3.987n C4 C1 OUT1 Q2 BC84685 E2 V2 B1 Q1 473 473 BC846B E1 V1 RE4731 15 + R2 R6 RE1 C2 1.12K 53.33k 1 Meg 2K 1.59 AC 1 .ac lin 101 50 20k

.op analysis-

x 17 C:\Users\Tushar Documents\LTspiceXVII\Draft26.asc Operating Point V(out): V(61): v(el) : V(vec): V(e2) : V(n002): V(n001): Ic (22) : Ib (02): Ie (02): Ic (01): Ib (Q1) : Ie (21) : I (01): I (04): I (05): I (C2): I (C3): I (R6): I (Re2): I (Rel): I (Rcl): I (R2): I (R1): I (V2): I (V1): 8.79781 voltage 3.7116 voltage 3.06471 voltage 15 voltage 8.10627 voltage 3.83427e-009 voltage 0 voltage 0.00721488 device_current 2.28609e-005 device_current -0.00723774 device_current 0.00152769 device_current 4.66893e-006 device_current -0.00153235 device current 1.75559e-015 device current 7.095e-015 device current -3.83427e-015 device_current 4.87289e-018 device current 2.47281e-020 device current 3.83427e-015 device current 0.00723774 device current 0.00153235 device current 0.00155055 device current 6.95968e-005 device current 7.42658e-005 device_current -0.00883969 device_current 1.75559e-015 device_current

Frequency response-

- х LTspice XVII - [Draft26] Eile View Plot Settings Simulation Tools Window Help 36% t^{3 DV ERE Aa.opo Draft26 Draft 26 Vin002) 45dB -100° 42dB =-110° 7.6438966KH2,42642184dB 39dB -120° 36dB -130° 33dB- -140° 30dB -- 150° 27dB- -160° 24dB -170° 21dB -180 18dB -190° 15dB- -200° 12dB- -210° 9dB- 220° +-230° 6dB 100Hz x = 149.190Hz y = 42.484dB, -108.387 1KHz 10KHz