Op-Amp Slew Rate Calculator
This calculator estimates required slew rate, maximum sine-wave frequency, or maximum sine-wave output amplitude using the ideal full-power bandwidth relationship.
Slew rate is a large-signal output speed limit. It must be checked separately from small-signal bandwidth and gain-bandwidth product.
Engineering tool
Op-Amp Slew Rate Calculator
Calculate required slew rate, maximum sine-wave frequency, or maximum sine-wave amplitude from the ideal full-power bandwidth relationship.
Sine-wave frequency used for required slew rate or maximum amplitude.
Peak output voltage of the sine wave.
Required Slew Rate
1.256637 V/µs
Full-power bandwidth is not the same as small-signal bandwidth.
Result console
- Required slew rate
- 1.256637V/µs
- Peak output voltage used
- 10V
- Peak-to-peak output voltage used
- 20V
- Frequency used
- 20kHz
- Formula used
- SRrequired = 2πfVpk
The calculated slew-rate limit does not guarantee that the op-amp has sufficient small-signal bandwidth, output swing, drive current, or settling performance.
Formula reference
Slew Rate Formula
These equations apply to sine-wave output signals. Square waves, pulses, and arbitrary waveforms require separate edge-rate and settling analysis.
Vout(t) = Vpk sin(2πft)max |dVout/dt| = 2πfVpkSRrequired = 2πfVpkVpk = Vpp / 2SRrequired = πfVppfmax = SR / (2πVpk)fmax = SR / (πVpp)Vpk,max = SR / (2πf)Vpp,max = SR / (πf)Variable definitions
- SR
- Op-amp slew rate in V/s, V/ms, or V/µs
- SRrequired
- Minimum ideal slew rate required for a sine wave
- f
- Sine-wave signal frequency
- fmax
- Ideal full-power bandwidth limit for the selected amplitude
- Vpk
- Peak output voltage
- Vpp
- Peak-to-peak output voltage
- t
- Time
- π
- Pi, approximately 3.14159
Variable Description
- SR
- Available op-amp slew rate, usually from the datasheet.
- SRrequired
- Minimum ideal slew rate required for the selected sine-wave output.
- f
- Signal frequency in Hz.
- fmax
- Maximum sine-wave frequency at the selected output amplitude.
- Vpk
- Peak output voltage from waveform centerline to one peak.
- Vpp
- Peak-to-peak output voltage, equal to 2 × Vpk for a centered sine wave.
- Vpk,max
- Maximum ideal peak voltage at the selected slew rate and frequency.
- Vpp,max
- Maximum ideal peak-to-peak voltage at the selected slew rate and frequency.
- t
- Time variable in the sine-wave equation.
- π
- Mathematical constant pi used in sine-wave slope calculations.
Worked Examples
Required Slew Rate from Peak Voltage
f = 20 kHz, Vpk = 10 V
SR = 2πfVpk ≈ 1.25664 V/µs
Required Slew Rate from Peak-to-Peak Voltage
f = 100 kHz, Vpp = 4 V
SR = πfVpp ≈ 1.25664 V/µs
Maximum Frequency
SR = 0.5 V/µs, Vpk = 5 V
fmax ≈ 15.9155 kHz
Maximum Amplitude
SR = 10 V/µs, f = 100 kHz
Vpk,max ≈ 15.9155 V, Vpp,max ≈ 31.8310 V
Audio Output Example
f = 20 kHz, Vpp = 20 V, Vpk = 10 V
Required SR ≈ 1.25664 V/µs
What Is Op-Amp Slew Rate
Slew rate is the large-signal maximum output voltage change rate.
Maximum Output Rate of Change
For a sine wave, the steepest slope occurs at the zero crossing.
Full-Power Bandwidth
Full-power bandwidth depends on output amplitude and slew rate.
Peak vs Peak-to-Peak Voltage
Vpp equals 2 × Vpk for a centered sine wave.
Sine-Wave Distortion
Slew limiting can distort a sine wave into a more triangular shape.
Positive and Negative Slew Rates
Some op-amps specify different rising and falling slew rates.
Small-Signal Bandwidth vs Slew Rate
Small-signal bandwidth does not guarantee large-signal sine-wave performance.
Gain-Bandwidth Product vs Slew Rate
GBW and slew rate describe different limits; both must be checked.
Output Swing Limits
Calculated amplitude may exceed real supply rails and output swing.
Load Current and Capacitive Load
Heavy or capacitive loads can reduce real dynamic performance.
Settling Time
Settling requirements may be stricter than the slew-rate limit alone.
Audio Applications
Slew rate matters for high-level, high-frequency audio output stages.
ADC Driver Applications
ADC drivers must satisfy slew, settling, output swing, and bandwidth needs.
Signal Generator Applications
Large, fast sine-wave outputs often run into slew-rate limits.
Common Mistakes
Confusing Vpk with Vpp
Check the waveform definition, units, datasheet limits, and real output conditions before relying on the ideal result.
Forgetting Vpp = 2Vpk
Check the waveform definition, units, datasheet limits, and real output conditions before relying on the ideal result.
Mixing V/s and V/µs
Check the waveform definition, units, datasheet limits, and real output conditions before relying on the ideal result.
Treating slew rate as gain-bandwidth product
Check the waveform definition, units, datasheet limits, and real output conditions before relying on the ideal result.
Treating full-power bandwidth as small-signal bandwidth
Check the waveform definition, units, datasheet limits, and real output conditions before relying on the ideal result.
Ignoring output swing and supply rails
Check the waveform definition, units, datasheet limits, and real output conditions before relying on the ideal result.
Ignoring load and capacitive load effects
Check the waveform definition, units, datasheet limits, and real output conditions before relying on the ideal result.
Assuming the theoretical limit has no distortion
Check the waveform definition, units, datasheet limits, and real output conditions before relying on the ideal result.
Applying sine-wave formulas directly to square-wave edges
Check the waveform definition, units, datasheet limits, and real output conditions before relying on the ideal result.
Not checking positive and negative slew-rate symmetry
Check the waveform definition, units, datasheet limits, and real output conditions before relying on the ideal result.
Support reference
FAQ
What is op-amp slew rate?
Slew rate is the maximum large-signal output voltage rate of change of an op-amp, usually specified in V/µs.
How do I calculate required slew rate for a sine wave?
For a sine wave, use SRrequired = 2πfVpk. If the amplitude is peak-to-peak, use SRrequired = πfVpp.
What is full-power bandwidth?
Full-power bandwidth is the maximum sine-wave frequency possible at a specified output amplitude before slew-rate limiting occurs.
What is the difference between peak and peak-to-peak voltage?
Peak voltage is measured from the centerline to one waveform peak. Peak-to-peak voltage is twice the peak voltage for a centered sine wave.
What happens when required slew rate is too high?
The output cannot follow the sine wave slope, so the waveform may distort and approach a triangular shape.
Is slew rate the same as bandwidth?
No. Slew rate is a large-signal output speed limit. Small-signal bandwidth and gain-bandwidth product describe small-signal frequency response.
Why does output amplitude affect maximum frequency?
A larger sine-wave amplitude has a larger maximum slope at the same frequency, so the same slew rate supports a lower full-power frequency.
Can the calculated maximum amplitude exceed the supply rails?
Yes. The calculation is an ideal slew-rate limit. Real output amplitude is still limited by supply rails, output swing, load, and distortion requirements.
Related Engineering Guides
Planned Engineering Guide
Understanding Op-Amp Slew Rate
Planned Engineering Guide
Full-Power Bandwidth Explained
Planned Engineering Guide
Slew Rate vs Gain-Bandwidth Product
Planned Engineering Guide
How to Read an Op-Amp Datasheet
Planned Engineering Guide
Op-Amp Output Swing and Supply Rails
Planned Engineering Guide
Driving Capacitive Loads with Op-Amps
Related Calculators
Voltage Follower Calculator
Calculate ideal unity-gain buffer output voltage, supply margin, and output saturation warning.
AvailableActive Low-Pass Filter Calculator
Calculate first-order active low-pass cutoff frequency, RC time constant, passband gain, and -3 dB magnitude.
AvailableActive High-Pass Filter Calculator
Calculate first-order active high-pass cutoff frequency, RC time constant, passband gain, and -3 dB magnitude.
AvailableOp-Amp Integrator & Differentiator Calculator
Calculate ideal op-amp integrator and differentiator output voltage, RC time constant, and characteristic frequency.
AvailableGain Bandwidth Product Calculator
Calculate required op-amp GBW, maximum closed-loop bandwidth, maximum gain, and noise gain.
Engineering Disclaimer
This calculator uses ideal sine-wave slew-rate equations for estimation and education. Real designs must verify output swing, supply rails, load current, capacitive load, gain-bandwidth product, closed-loop gain, settling time, distortion target, temperature, and positive or negative slew-rate asymmetry before hardware release.