Analog Electronics with LabVIEW®

1.3. Frequency Response of the Amplifier Stage

Capacitance associated with amplifiers may cause the output to fall off at low and high frequencies. This effect is referred to as the frequency response of the amplifier. A generalization of possible capacitance is shown in the circuit of Fig. 1.3. Capacitor C_g is an external capacitance, which is included to attach a sine-wave signal source, consisting of V_sig (e.g., sine-wave peak) and R_s, without interrupting the dc bias circuitry. Similarly, there could be an output capacitance, which couples the signal output voltage to an external load resistor. Capacitor C_T is associated with the internal capacitance of the transistor. It may be regarded as an equivalent effective capacitance that represents ...