There is a circuit based on TTL( transistor transistor logic I think) . The signals at points A B C D are described. I am new with this TTL, could you help me decompose this united circuit into the logic components which it consists from? Thanks.
1 Answer
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It seems to be a simple inverter.
Assuming no other connections, resistors and supply as shown, we can simplify the circuit as so:
simulate this circuit – Schematic created using CircuitLab
which has a DC transfer function from V1 (A) to D,
give or take the setting of your R13, here set all the way towards C.
It's more or less an emitter follower-buffered negative-voltage (PNP type) RTL inverter, with level shift at the input.
The Darlington follower (Q2 into Q3) doesn't seem very useful, but without knowledge of application and ratings, that's neither here nor there.
answered Mar 30 at 15:26
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\$\begingroup\$ Hello Mr. Williams, point A is a pulse of 0-3.3V at 120ns.I am trying to understand and simulate each step. given my original circuit could you please explain what is the logic from point A to B? they have an intresting diode in parralel with capacitor, and some things near the -2.5V power supply. whatis the logic in that?Thanks. \$\endgroup\$– Chris95Commented Mar 30 at 19:12
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\$\begingroup\$ There is no logic function, simply a level shift. You can simulate the circuit to see voltages. LM4040 is a 2.5V regulator that has been replaced here with a voltage source. \$\endgroup\$ Commented Mar 31 at 1:15
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\$\begingroup\$ Hello Tim, so between A and B is a level shifter. what is the analog logic of the part show between the two arrows in the attached link? ibb.co/Rv19L07 \$\endgroup\$– Chris95Commented Apr 2 at 17:33
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\$\begingroup\$ That's the Darlington emitter follower part. \$\endgroup\$ Commented Apr 2 at 18:14
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\$\begingroup\$ Hello Tim, I want to simulate the level shifter part from points A to B however i dont know what input pulse its intended for and what output value it supposed to produce on point B. Could you please say what input signal to use and what output value on point B should i expect on the otput? Thanks. \$\endgroup\$– Chris95Commented Apr 3 at 9:25
V_CONis, and what J11-J14 are or what might be attached to them? \$\endgroup\$