What is function of this complicated circuit?

Thread Starter

xxxyyyba

Joined Aug 7, 2012
289
Hello. Here is my task:

a) Explain principle of working of circuit below. Draw waveforms of voltage at points A, B, C, D and Q, as well as capacitors voltage waveforms.
b) What is minimum time constant of charging of C3 (ie value of resistance R6) so that voltage waveform of point Q are rectangular pulses

It is known: R1, R2, R3 (R2=R3), R4, R5, R6, C1=C2=C3, 5R1>>R2 and R1>>R3. Threshold voltage equals VDD/2.

ddd.png

Any suggestion?
I did nothing because I have no idea how to start :( I'm beginner in Digital electronics. In analog electronics and in circuit theory, there are well known methods for solving circuits, but what to do here? I'm really stuck :(

EDIT: This is not homework question. I don't have final result. This was on my exam. I didn't solve it on exam and I'm trying to figure out what is solution to this problem. Every suggestion is welcome, I want to pass exam next time :)
 
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Thread Starter

xxxyyyba

Joined Aug 7, 2012
289
Hello, thanks a lot for reply. So original "complicated" circuit consists of few simple circuits conected together and to understand "complicated" circuit, I should first understand its "parts", right?
But then it's not clear to me: Let's say I analysed first part of this circuit (astable generator) and found voltage waveform at point B. If I then connect second part to it (high pass filter - C2R4), it would "interact" with previous stage and, logically, waveform of point B I got when analyzed first stage on it's own will CHANGE?
 
Last edited:

Jony130

Joined Feb 17, 2009
5,089
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