Analog Electronics with LabVIEW®

Unit 10. Common-Source Amplifier with Current-Source Load

The amplifier in this part is the same, in principle, as the basic common-source amplifiers of Figs. 2.4 and 5.1. However, now the actual resistor R_D is replaced with a current-source load as shown in the circuit of Fig. 10.1. As noted in Unit 9, a benefit of replacing bias resistors with current sources is a reduced requirement for resistors in the circuit; the reference voltage associated with M₃ can be used elsewhere in a typical circuit. Additionally, as will be shown, the gain of the common-source stage is substantially improved over that with actual bias resistor R_D. The specific circuit of Fig. 10.1 is that for the project amplifier. The bias and gain of the amplifier are evaluated ...