Circuit Design / interactive engineering
Cascaded Op-Amp Gain Designer
Build an inverting or non-inverting multi-stage amplifier, see total gain, and compare common op-amp ICs.
Answer first
How do I split a required gain across multiple op-amp stages?
Set the input signal, target gain, and stage configuration to divide amplification across several op-amps. The designer calculates each ideal stage gain, resistor relationship, and final output, then draws the full cascade. Check supply rails, input and output range, bandwidth, noise, bias current, stability, and resistor tolerances before selecting the IC.
01 / Define each stage
Build the signal path
Stage 1
Stage 2
02 / Inspect the cascade
Gain, polarity and the actual feedback circuit
Ideal DC/small-signal gain only. Each stage’s output feeds the next input. No supply rails, bias point, clipping, bandwidth, noise or output-current limits are simulated. A real output cannot exceed its available swing.
03 / Package reference
Know the pins before wiring
Select a reference IC, then select a pin. These 8-pin PDIP top views are not interchangeable with every package or suffix.
Notch at the top: pins 1–4 down the left, 8–5 down the right.
LM358 · pin 1
1 OUT A
Verify supply range, common-mode range, output swing, and bandwidth in the exact datasheet.
Open manufacturer datasheet ↗Complete cascade circuit
Show every calculated stage, its feedback resistors and the wire connecting each output to the next input. Ground symbols share the same signal reference. Supply and bias wiring are not modeled.
Design guide
Use the result with engineering context
Technical content reviewed
When this tool is useful
- Avoiding one impractically high-gain op-amp stage
- Comparing inverting and non-inverting stage arrangements
What the result includes
- Per-stage gain, total ideal gain, and resistor values
- Individual and complete circuit views with common IC options
What the model does not guarantee
- Ideal gain does not include gain-bandwidth limits, slew rate, noise, offset, bias current, loading, or tolerance
- The drawing omits the final PCB layout, decoupling strategy, input protection, and complete power connections
Worked approach
Share gain without losing bandwidth
Start from the required total gain and signal bandwidth. Split the gain into practical stages, then check that each selected op-amp has enough gain-bandwidth product, slew rate, common-mode range, and output swing.
Common decisions
Questions engineers ask
Why use two stages instead of one high-gain stage?
Multiple stages can make resistor ratios and bandwidth easier to manage. They also let you place filtering or bias control between stages, though every stage adds noise, offset, parts, and stability concerns.
Will the calculated output voltage always be available?
No. The output clips when the requested voltage or current exceeds the op-amp's output swing, current limit, slew rate, or supply rails.
Can I choose any resistor pair with the correct ratio?
The ratio sets ideal gain, but absolute values affect noise, bias-current error, loading, power, and interaction with input capacitance. Use the datasheet and circuit impedance requirements to choose the range.
Related build evidence
Real-Time Muscle Activity Monitoring
See a complete sensing system that captures and displays a changing signal. This is adjacent signal-chain evidence and does not claim the displayed op-amp stages or resistor values were used.
See the projectApply it to real hardware
Need a sensor signal chain sized for real hardware?
Share the sensor range, bandwidth, offset, supply rails, ADC range, noise target, and available op-amps so the gain stages can be reviewed together.
Discuss the system