The THD measurements at voltage levels 2.83 - 5.6 V were carried out with High Pass Filter "on" (2nd order Buttreworth type, 800 Hz cutoff, HPF2-800)
The THD measurements at voltage level 8 V were carried out with High Pass Filter "on" (4th order Buttreworth type, 1000 Hz cutoff, HPF4-1k)