Mirror capacity

In bipolar transistors and field-effect transistors, the phenomenon in which the capacitance between the base and emitter or between the gate and source acts multiplied by the gain (amplification factor) of the capacitance between the base and collector or gate and drain is called the Miller effect, and the input-side capacitance is referred to as the Miller capacitance. If the capacitance between input and output is C and the amplification factor is A, then the Miller capacitance (input capacitance) is expressed by the following formula.

Miller capacitance = C(A+1)

In the Miller effect, a small capacitance between the input and output is amplified, becoming a large Miller capacitance (input capacitance), which affects the frequency characteristics. The name comes from the discoverer and is unrelated to the mirror in the sense of a reflective surface.