Low distortion opamp IC which can drive PWM input

asenapati

Member
2015-11-20 4:24 am
Hi,

I need an opamp IC to make a lowpass butterworth filter (order=2, cutoff freq=150kHz) using a biquad arrangement. The input to the filter is output of an H-bridge which is basically PWM output.

The opamp must have THD < 0.001% (-100dB) for a PWM input. Is this kind of distortion performance a practical no. in ICs? Could someone suggest an opamp IC ?

Thanks and regards,
Ananya
 

asenapati

Member
2015-11-20 4:24 am
I think, slew rate and level of signal definitely affect distortion. So, we have to make sure that both of these parameters are such that they don't add to the THD.

Common mode signal also does matter. But I am not sure what parameter to look for in the opamp datasheet for this. I am planning to simulate the spice model to make sure that the particular IC is suitable for me.