JAJSTJ2 June 2024 DRV2911-Q1
PRODUCTION DATA
Having an appropriate local bulk capacitance is an important factor in optimal driver performance. It is generally beneficial to have more bulk capacitance, while the disadvantages are increased cost and physical size.
The amount of local capacitance needed depends on a variety of factors, including:
The inductance between the power supply and the drive system limits the rate that current can change from the power supply. If the local bulk capacitance is too small, the system responds to excessive current demands with a change in voltage. When adequate bulk capacitance is used, the output voltage remains stable, and a high current can be quickly supplied.
The data sheet generally provides a recommended value, but system-level testing is required to determine the appropriate sized bulk capacitor.
The voltage rating for bulk capacitors should be higher than the operating voltage, to provide margin for optimal driver performance.