rftools.io

Op-Amp Closed-Loop Bandwidth Calculator

Calculate op-amp closed-loop -3dB bandwidth from the gain-bandwidth product (GBW), determine rise time, and verify phase margin.

Loading calculator...

Formula

BW = \frac{GBW}{A_{CL}},\quad t_r = \frac{0.35}{BW}

Reference: Texas Instruments, "Op Amp Applications Handbook"

GBWGain-bandwidth product (Hz)
A_CLClosed-loop gain (V/V)
BW-3dB bandwidth (Hz)
t_r10-90% rise time (s)

How It Works

Operational amplifiers (op-amps) have a fundamental performance characteristic called gain-bandwidth product (GBP), which represents the maximum frequency at which the amplifier can maintain a specific gain. The closed-loop bandwidth is calculated by dividing the op-amp's gain-bandwidth product by the desired closed-loop gain, representing the maximum frequency at which the amplifier can accurately amplify signals.

Worked Example

Problem: Calculate the closed-loop bandwidth for a non-inverting amplifier with a GBW of 1 MHz and a closed-loop gain of 10 Solution: 1. Gain (Av) = 10 2. GBW = 1 MHz 3. Closed-Loop Bandwidth = GBW/Av = 1 MHz / 10 = 100 kHz 4. Rise Time = 0.35 / BW = 0.35 / (100 kHz) = 3.5 microseconds

Practical Tips

  • Always check manufacturer's datasheet for precise GBW specifications
  • Lower gains provide wider bandwidth
  • Consider temperature and component variations in design

Common Mistakes

  • Assuming linear bandwidth across all gains
  • Neglecting the GBW limit when designing amplifier circuits
  • Not accounting for actual op-amp specifications

Frequently Asked Questions

Shop Components

Affiliate links — we may earn a commission at no cost to you.

Resistors (E24, 1%)

Precision thin/thick film SMD resistors in 0402 package

Ceramic Capacitors

Multilayer ceramic capacitors (MLCC) in 0402 package

Solderless Breadboard

Full-size and half-size breadboards for prototyping

Related Calculators