Hi everyone, I can't find an answer to this question and would like to hear from anyone who can explain the theory and show measurements.
"Matched" components in various amplifier topologies are an advantage in gain-matching as well as distortion cancellation. Is there any advantage in closely matching the L/C/R characteristics of the filter components in a Class D BTL output stage? Most of the components specified for Class D amplifier filters have a large tolerance eg +/-20%. Would it make any difference to have +/- 1%?
Thanks,
Mike
"Matched" components in various amplifier topologies are an advantage in gain-matching as well as distortion cancellation. Is there any advantage in closely matching the L/C/R characteristics of the filter components in a Class D BTL output stage? Most of the components specified for Class D amplifier filters have a large tolerance eg +/-20%. Would it make any difference to have +/- 1%?
Thanks,
Mike
The HF response of the amp may well be affected by low tolerance filter component values, 20% isn't really acceptable IMO - 5% or better ought to be easily sourced.
The roll-off for many output filters will start at or around 15--20kHz in order to get good attenuation of the carrier frequency, and the shape of that response from 5kHz up may be sensitive to component values. Also a filter normally assumes a particular load impedance, and will have a differet response into a different speaker impedance, as the Q is mainly set by the loudspeaker voice coil...
The roll-off for many output filters will start at or around 15--20kHz in order to get good attenuation of the carrier frequency, and the shape of that response from 5kHz up may be sensitive to component values. Also a filter normally assumes a particular load impedance, and will have a differet response into a different speaker impedance, as the Q is mainly set by the loudspeaker voice coil...
