Question

Consider a noninverting amplifier stage with the DC voltage gain of 10 times and the -3 dB bandwidth of 100 MHz. It is a low pass filter.

The gain of a single stage was not sufficient for a certain application so that two identical stages were connected in tandem: the output of the 1st stage was connected to the input of the 2nd stage.

The output of the 2nd stage served as the output of the 2-stage circuit.

1. What would be the DC gain of the 2-stage circuit in dB units?

Answer 1

The overall DC gain of a two-stage amplifier circuit, where each stage has a gain of 10 times, is 40 dB after combining the individual gains in decibels.

Step-by-step explanation:

To determine the DC gain of a two-stage amplifier circuit in decibel (dB) units, we consider the gain of each individual stage, which is given as 10 times, or equivalently in dB, 20 dB (since 20*log10(10) = 20). When two identical amplifier stages are connected in series (cascaded), their gains multiply. Therefore, for the two stages, the overall voltage gain would be 10 times 10, which equals 100 times. The gain in decibels is calculated by taking 20 times the logarithm to the base 10 of the voltage gain: 20*log10(100) = 40 dB. So the DC gain of the two-stage circuit in dB would be 40 dB.