Question

CO RC Vout Q1 Rsrc Cin Vin IC In the above circuit Ic-11 .48mA. Rc-190Q, Rare-30Ω. C,-7pF, C,-2pF. CCS-3pF. Find the amplifier's high frequency poles. Use VT-26mV and β-105 Sp.in MHz p,in MHz Sp.out 8

Answer 1

G_m = I_C/VT g_m = 11.48/26 = 0.441 Vertical-bar S_p, in Vertical-bar = 1/2 pi (R_src // 1/g_m) C_x C_x = C_pi = 2PF R_src // 1/g_m = (30 Ohmign) // 1/0.441 = 2.1 Ohmign Vertical-bar S_p, in Vertical-bar = 1/2 pi (2.1) (2 times 10^-12) = 37894.3 MHz Vertical-bar S_p, out Vertical-bar = 1/2 pi (R_c) (CY) CY = C_mu + C_cs = 7PF + 3PF = 10PF R_C = 190 Ohmign \r\n Vertical-bar S_p, out Vertical-bar = 1/2 pi (190) (10 times 10^-12) Vertical-bar S_p, out Vertical-bar = 83.765 MHz