SLOS681C January 2011 – August 2019 DRV632
PRODUCTION DATA.
DC input-blocking capacitors are required to be added in series with the audio signal into the input pins of the DRV632. These capacitors block the dc portion of the audio source and allow the DRV632 inputs to be properly biased to provide maximum performance.
These capacitors form a high-pass filter with the input resistor, RIN. The cutoff frequency is calculated using Equation 3. For this calculation, the capacitance used is the input-blocking capacitor, and the resistance is the input resistor chosen from Table 1; then the frequency and/or capacitance can be determined when one of the two values is given.
It is recommended to use electrolytic capacitors or high-voltage-rated capacitors as input blocking capacitors to ensure minimal variation in capacitance with input voltages. Such variation in capacitance with input voltages is commonly seen in ceramic capacitors and can increase low-frequency audio distortion.