CAD LAB EXPERIMENT No. - 1

Aim –    (a) Transient Analysis of BJT inverter using step input.

              (b) DC Analysis (VTC) of BJT inverter with and without parameters.

Simulator Used – PSpice.

Theory – Transistor functions as an inverter, when operated in only the cutoff and the saturation regions of the transistor amplifier, not in the linear region. When the input voltage is low, the transistor does not conduct, there is no current and the collector voltage (output) is pulled up to V_CC. When the input voltage is increased, the transistor begins to conduct, the voltage drop across R_C starts increasing, and the output voltage falls. Finally, when the input voltage is high enough to drive the transistor into saturation, there is a fixed small drop (V_CE=0.1 to 0.2 V) across the transistor and the output voltage saturates to this low value.

Voltage Transfer Characteristic graph of transistor gives the relation between input voltage i.e. base voltage and the output voltage i.e. collector voltage. In this it is seen that the transistor operates in three regions i.e. cut off region, forward active region and saturation region.

Circuit Diagram –

Result –

Conclusion - (a)Transient Analysis of BJT inverter using step input  

                         has been performed.

                      (b) DC Analysis (VTC) of BJT inverter with and without 

                            parameters has been performed.