SCDA058 September   2025 TMUX1575 , TMUX4827 , TMUX7612 , TS5A22362 , TS5A22364

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2What is THD
  6. 3What is THD + N
  7. 4THD(+N) of Multiplexers
    1. 4.1 Understanding THD(+N) of a Multiplexer
  8. 5Low THD Multiplexer Applications
  9. 6Low THD Mux Device Recommendations
  10. 7Summary
  11. 8References

4 THD(+N) of Multiplexers

The THD + N test setup schematic for a multiplexer (MUX) device is shown in Figure 4-1. A low distortion sine wave source, Vin, is applied to the MUX channel under test S1 to D. The output signal, noise and harmonics are captured by a precision digitizer. This measurement is conducted over a range of Vin frequencies (for example, for audio applications, sweep is 20Hz to 20kHz), and the results are combined to form a plot of THD + N across frequency.

Test Setup Schematic for Measuring Multiplexer THD+NFigure 4-1 Test Setup Schematic for Measuring Multiplexer THD+N