5.1 Slew Rate

The slew rate of an operational amplifier determines how fast the output signal can rise and fall. With an ideal square wave input, the output edges of the waveform should be near vertical, however a real waveform will have sloped edges, as shown in Figure 5-1.

Figure 5-1. Example of a slew rate limit

Another consequence of slew rate is a reduction in bandwidth with high amplitude signals. This can be shown by calculating the derivative of the input signal. If the rate of change exceeds the slew rate, it will be limited to the maximum slew rate of the device, even if the signal is within the available bandwidth.