The original 0.5Mhz sinusoidal signal was input into the Class D power amplifier after PWM encoding, but once it was connected to the power amplifier, the signal was severely distorted. What caused this? Is there any solution? Figure 1 is the direct output of the signal through the comparator. Figure 2 is the output PWM waveform. Figure 3 shows the signal connected to the Class D power amplifier, and Figure 4 shows the signal change after it is connected to the power amplifier. What is the reason for this phenomenon? Is there any solution?
Nena Posted on February 1, 2021
For the comparator, you can adjust its output capability in the software. It is estimated that the MOS tube will need to be replaced. Look for MOS tube with large input impedance and pay attention to other parameters.
Horatio Posted on February 1, 2021
It feels like the switching speed of the MOS tube you use is not enough.
Snow Posted on February 1, 2021
It is possible that the input impedance of your MOS tube is too low, and the drive capability of the comparator may not be enough.