The DRV8802-Q1 is designed to operate from an input voltage supply V_(VMx) range between 8.2 and 45 V. Two 0.1-µF ceramic capacitors rated for V_(VMx) must be placed as close as possible to the VMA and VMB pins respectively (one on each pin). In addition to the local decoupling caps, additional bulk capacitance is required and must be sized accordingly to the application requirements.

9.1 Bulk Capacitance

Bulk capacitance sizing is an important factor in motor drive system design. It is dependent on a variety of factors including:

• Type of power supply
• Acceptable supply voltage ripple
• Parasitic inductance in the power supply wiring
• Type of motor (Brushed DC, Brushless DC, Stepper)
• Motor startup current
• Motor braking method

The inductance between the power supply and motor drive system will limit the rate current can change from the power supply. If the local bulk capacitance is too small, the system will respond to excessive current demands or dumps from the motor with a change in voltage. You should size the bulk capacitance to meet acceptable voltage ripple levels. The datasheet generally provides a recommended value but system level testing is required to determine the appropriate sized bulk capacitor.

Figure 10. Example Setup of Motor Drive System WIth External Power Supply

9.2 Power Supply and Logic Sequencing

No specific sequence exists for powering-up the DRV8802-Q1 device. Digital input signals can be present before V_(VMx) is applied. After V_(VMx) is applied to the DRV8802-Q1 device, it begins operation based on the status of the control pins.