ZHCS389C June 2011 – December 2022 DRV8662
PRODUCTION DATA
Depending on the quality of the source signal provided to the DRV8662, an input filter may be required. Some key factors to consider are whether the source is generated from a DAC or from PWM and the out-of-band content generated. If proper anti-image rejection filtering is used to eliminate image components, the filter can possibly be eliminated depending on the magnitude of the out-of-band components. If PWM is used, at least a 1st order RC filter is required. The PWM sample rate should be greater than 30 kHz to keep the PWM ripple from reaching the piezo element and dissipating unnecessary power. A 2nd order RC filter may be desirable to further eliminate out-of-band signal content to further drive down power dissipation and eliminate audible noise.