Cascaded Amplifier Gain

Av = Av1 · Av2 · Av3

Quick answer

This calculator solves Av(total) = Av1 × Av2 × Av3 for Total Gain. With Stage 1 Gain 1.1, Stage 2 Gain 2.35, Stage 3 Gain 0.235, the result is 0.6075. It solves in 4 directions, so you can enter the values you have and get the one you need.

Calculator

Total Gain
—

Formula

Av(total) = Av1 × Av2 × Av3

Description

When amplifier stages are cascaded, their voltage gains multiply (their decibel gains add). This lets a large overall gain be built from modest, well-behaved stages, each loaded by the next stage’s input impedance. For unused stages set the gain to 1. The same rule extends to any number of stages.

Variables

  • Av(total) — Overall voltage gain
  • Av1 — Stage 1 gain (set unused = 1)
  • Av2 — Stage 2 gain (set unused = 1)
  • Av3 — Stage 3 gain (set unused = 1)

Practical Notes

In decibels the gains add: 20 dB + 20 dB + 20 dB = 60 dB = ×1000. Remember each stage’s gain already includes the loading of the following stage’s input impedance.

Symbols and units

Symbol Meaning Default unit Accepted units
Avt Total Gain — —
Av1 Stage 1 Gain — —
Av2 Stage 2 Gain — —
Av3 Stage 3 Gain — —

Step by step

  1. 1. What you know: Stage 1 Gain 1.1, Stage 2 Gain 2.35, Stage 3 Gain 0.235
  2. 2. The relation: Av(total) = Av1 × Av2 × Av3
  3. 3. Substitute: Av1 = 1.1, Av2 = 2.35, Av3 = 0.235
  4. 4. Result: Total Gain = 0.6075

Worked examples

Minimum range

Given: Stage 1 Gain 0.055, Stage 2 Gain 0.118, Stage 3 Gain 0.0118

Result: Total Gain = 7.66 × 10⁻⁵

Low range

Given: Stage 1 Gain 0.55, Stage 2 Gain 1.18, Stage 3 Gain 0.118

Result: Total Gain = 0.07658

Typical

Given: Stage 1 Gain 1.1, Stage 2 Gain 2.35, Stage 3 Gain 0.235

Result: Total Gain = 0.6075

High range

Given: Stage 1 Gain 1.76, Stage 2 Gain 3.76, Stage 3 Gain 0.376

Result: Total Gain = 2.488

Maximum range

Given: Stage 1 Gain 17.6, Stage 2 Gain 37.6, Stage 3 Gain 3.76

Result: Total Gain = 2488

Solving for each variable

Solve for Total Gain

Stage 1 Gain 0.055, Stage 2 Gain 0.118, Stage 3 Gain 0.0118 → 7.66 × 10⁻⁵

Solve for Stage 1 Gain

Total Gain 0.025, Stage 2 Gain 0.118, Stage 3 Gain 0.0118 → 17.95

Solve for Stage 2 Gain

Total Gain 0.025, Stage 1 Gain 0.055, Stage 3 Gain 0.0118 → 38.52

Solve for Stage 3 Gain

Total Gain 0.025, Stage 1 Gain 0.055, Stage 2 Gain 0.118 → 3.852

How Total Gain changes with Stage 1 Gain

Stage 1 Gain (input) Total Gain (result)
0.11 0.06075
0.275 0.1519
0.55 0.3037
0.825 0.4556
1.1 0.6075
1.65 0.9112
2.2 1.215
4.4 2.43
7.7 4.252
11 6.075

Embed this calculator

Paste this into any page. It keeps working when this page updates, and credits the source.

<iframe src="https://vbatpower.com/embed/cascaded-gain/" width="100%" height="460" style="border:1px solid #1f2a37;border-radius:12px" loading="lazy" title="Cascaded Amplifier Gain"></iframe>
<p><a href="https://vbatpower.com/formulas/cascaded-gain/">Cascaded Amplifier Gain</a> Calculator by vbatpower.com</p>

Frequently asked questions

How do you calculate Cascaded Amplifier Gain?

Use Av(total) = Av1 × Av2 × Av3. With Stage 1 Gain 1.1, Stage 2 Gain 2.35, Stage 3 Gain 0.235, Total Gain works out to 0.6075.

What is the formula for Cascaded Amplifier Gain?

The formula is Av(total) = Av1 × Av2 × Av3. When amplifier stages are cascaded, their voltage gains multiply (their decibel gains add).

How do you find Stage 1 Gain when you know the other values?

Rearrange for Stage 1 Gain: with Total Gain 0.025, Stage 2 Gain 0.118, Stage 3 Gain 0.0118, Stage 1 Gain is 17.95.

How do you find Stage 2 Gain when you know the other values?

Rearrange for Stage 2 Gain: with Total Gain 0.025, Stage 1 Gain 0.055, Stage 3 Gain 0.0118, Stage 2 Gain is 38.52.