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DRV8886: DRV8886 Bulk Capacitor

user5981129
Prodigy 30 points
Part Number: DRV8886

Hello,

I have the following questions related to the right performance of the bulk capacitor and the suitability of this capacitor in small PCBs.

- Is it necessary to use an electrolytic capacitor? Could I use one or several ceramic/tantalum capacitors instead?

- Is there an estimate value of the bulk capacitor according to the current changes of the driver? Could this capacitor be shared by 4 drivers, or each driver needs its own bulk capacitor?

Thanks in advance

J.R.

  • 0
    TI__Expert 8985 points
    Hi User,

    For the capacitor's material: I will research further and get back to you.

    Traditionally, we recommend the selection of the bulk capacitor's capacitance to be 2-4 uF / W. Nevertheless, the bulk capacitance is also dependent on the highest current required by your system, understanding the motor, the power supply, cabling, connectors, PCB layout, etc. System testing will need to be done to verify this. See section 9.1 for more guidelines.

    The capacitor should exist local to each power stage for FET/motor/load dependent current dissipation, voltage ripple, parasitic inductance, etc.
  • 0 in reply to Hector Hernandez Luque
    TI__Expert 8985 points
    Hi User,

    For the capacitor's material: you can utilize other materials other than electrolytic. However, note that the other materials can lead to a cost that can be prohibitive and have a lower bias voltage, even though the other materials provide a lower ESR than electrolytic.