Analog Electronics with LabVIEW®

8.7. Voltage Gains Including Transistor Output Resistance

In Project 9 we measure the gain of a “balanced” stage with drain resistors for both transistors. The amplifier is the PMOS version of the NMOS amplifier of Fig. 8.2. We obtain an exact Level 1 SPICE solution for the gains for both outputs. The example is used to explore the use of a simulator for obtaining precision results to compare with simple hand calculations.

For larger λ_n values (NMOS), the output resistance can influence the gain and complicate the gain expressions considerably. Here we consider the effect due to g_ds1 and g_ds2 while retaining the effect of R_bias. In the following, the gain of the inverting input, a_v1, is obtained again as a common-source stage with source resistance. ...