Calculating CC amp with bootstrap

DC Circuit on the left, complete circuit in the middle and AC circuit on the right. DC Circuit Rs = 10k R1 = 20k RE = 5.1k Beta = 300 VCC = 10V ==> VB = VCC*(R1/(R1+R1)) = VCC/2 = 5V ==> VE = VB - VBE = 5V - 0.7V = 4.3V ==> IE = VE/RE = 4.3V/5.1k = 843uA _________________________________ AC Circuit R1b = R1/2 = 20k/2 = 10k RL = 10k Rs = 10k gm = IE/VT = 843uA/25mV = 33.7mA/V Vs = 1V ==> Re = VT/IE = 25mV/843uA = 29.66Ohm ==> Req1 = R1b||R1b||Beta*Re = 10k||10k||300*29.66 = 3.2k ==> Req2 = R1b||R1b||RE||RL = 10k||10k||5.1k||10k = 2.02k ==> -Vs + Is*Rs + Is*Req1 + Is*Req2*(1 + gm*Req1) = 0 ==> Is = Vs/(Rs + Req1 + Req2*(1 + gm*Req1) = 1V/(10k + 3.2k + 2.02k*(1 + 33.7mA/V*3.2k) = 4.29uA ==> Vo = Is*Req2*(1 + gm*Req1) = 4.29uA*2.02k*(1 + 33.7mA/V*3.2k) = 0.943V Simulation Vo = (Vmax + |Vmin|)/2 = (0.928V+ 0.942)/2 = 0.935V Calculated Vo = 0.943V Done

published 6 years ago