29:47 why the left and right current v3/rd have different direction, isn't it current mirror? I thought in previous courses, current mirror always produce same direction current??
something creating confusion is this : the standard equation of the shortcut is written as: alpha(dy over dt) + y = x(t) next we see a calculation of y(t) using y(inf) and y(0)..... meaning the x(t) is y(t).... in the first example we calculate I1(t) with this putting I(inf) and I (0) in the arguments... and again x(t) seems to be y(t) so the standard formula looks to be alpha(dy/dt) + y = y(t) all good so far, until the second example : here we see V1 = R1C1(dVout/dt) + Vout(1 + R1/R2) a little shocking, since V1 is a constant and not a function of time..... some algebra however solved this since by deviding all the terms by (1 + R1/R2) the V1 in the equation transformed into Vout and alpha(dy/dt) + y = y(t) is now respected.... hope my confusion can help some people going looking into these quit nice lessons
one could argue that the voltage source has the same behaviour as a capacity C1 of earlier lesson where 2 capacitors were involved. The voltage source has the behaviour of a Capacity C1 that cannot be decharged, or otherwise said is very very large this results into Vout (at t = infinite) = V1* C1 / C1 + C2 with very big C1 this becomes Vout (at t = infinite) = V1
so basically to decrese ripple we need to increase capacitance. can anyone tell me what if we put a buffer in between cap and load then i guess load won't affect the voltage across cap so i guess there won't be any discharging?
00:51 Developing a circuit model for the bipolar transistor 04:29 Transconductance measures the strength of a bipolar device in translating a voltage change to a current change 10:19 Transistor can act as a current source and its values can change. 13:47 Finding IC as a function of time 19:59 Dependent current source placement in simplest bipolar transistor model 22:21 Modeling the base current using a diode 28:04 Transistor model replacement and circuit simplification 31:10 Analyzing large-signal and small-signal operation of Razavi Electronics 37:26 Nonlinear functions require mathematical labor in bipolar transistor circuits. 40:27 Analysis of voltage and current in the circuit with a sinusoidal microphone signal 47:45 Large signal operation allows for signals of any amplitude, leading to complex exponential expressions for IC. 50:57 Small-signal operation assumes input signal is small compared to the bias voltage. 57:35 Small signal operation leads to sinusoidal behavior of collector current. 1:00:42 GM times input voltage equals current fluctuation
the best part is the practical application and the entire signal chaining . I just pose the video try thinking of what should be the next block like we had today laptop charger.
Seems there is a logical fallacy around the 32-33th minute which is this: the saturation condition of the non-degenerate MOS is V_DS > = V_GS - V_th => V_DS > = VG - V_th (assuming the source S is grounded, so V_GS = VG - 0 = VG). However, with degeneration, the condition is still the same except that the source S is no more grounded, and therefore, the condition becomes V_DS > = V_GS - V_th = VG - VS - V_th = VG - ID*Rs - V_th ... so, the left (lower) limit of the saturation region from the value of VG - V_th then shifts to the value of VG - ID*Rs - V_th <= VG - V_th i.e. to a lower value (or, in other words, the saturation region seems broader against the triode region). Why is the saturation region then sacrificed upon degeneration (assuming the same VG to ground in both cases)?
the best lecturer. as my age is lesser than his experience you earned my respect mr razavi one word i want to say to you the best faculty i've ever seen in this generation.
Sir during solving for output impedances as we are setting the Vgs as 0 so the device should be off at the time so all the effects of channel length modulation cant be there as it is in triode region so the r0 should always be= infinity isn't that true
I am an electrical engineering student studying basic electronics for the first year course, I hope I find a teacher like you who teaches electrical subjects so effieciently.. Learning from you I regret why did not I choose electronics. Well thank you very much sir from India
