7.3.1 Distortion Reduction

Amplifiers use feedback to reduce the amount of distortion they introduce to the signal path. Increasing the amount of feedback available for distortion reduction typically requires an increase in the power supply current of the amplifier. This is not acceptable in low-power amplifiers targeting applications that require low distortion.

Figure 53. Comparison of THD + N vs Frequency for Multiple Low-Power Amplifiers

The OPA169x family of amplifiers uses a proprietary technology to reduce signal distortion that does not increase the power supply current. The distortion cancellation technique reduces odd-order harmonic distortion, which is produced by the input transistor pair of the amplifier. As Figure 53 shows, the impact to THD + N is significant, especially at high frequencies where the OPA169x devices exhibit over 30-dB lower distortion than competitor amplifiers at similar power supply current levels.