Applications of the CA3080 High-Performance Operational Transconductance Amplifiers
H. A. Wittlinger · 2002
This Application Note describes the operation of the OTA and features various circuits using the OTA. For example, communications and industrial applications including modu- lators, multiplexers, sample-and-hold-circuits, gain control circuits and micropower comparators are shown and dis- cussed. In addition, circuits have been included to show the operation of the OTA being used in conjunction with CMOS devices as post-amplifiers. Figure 1 shows the equivalent circuit for the OTA. The output signal is a current which is proportional to the transconduc- tance (gM) of the OTA established by the amplifier bias cur- rent (IABC) and the differential input voltage (eIN). The OTA can either source or sink current at the output terminal, depending on the polarity of the input signal.