TTL INVERTER

Load the PSPICE file ttl-inv.sch, Figure 48.

**Figure 48:** TTL inverter circuit.
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Simulate the circuit and obtain the INVERTER input-output curve of Figure 49. Explain, as best you can, what happens as V_in is increased from 0 V to V_CC=5 V.

**Figure 49:** TTL inverter input-output curve.
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For V_in=0 V (i.e. LOW), work out the state or mode of operation for each transistor (saturated, active, cut off), and deduce that V_out should be HIGH (value?)
Do the same for V_in=5 V (i.e. HIGH), and this time deduce that V_out should be LOW (value?)
To do this, examine transistor currents and voltages.

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