The DRV8848 is designed to operate from an input voltage supply (V_VM) range between 4 and 18 V. Place a 0.1-µF ceramic capacitor rated for VM as close to the DRV8848 as possible. In addition, the user must include a bulk capacitor of at least 10 µF on VM.

9.1 Bulk Capacitance Sizing

Bulk capacitance sizing is an important factor in motor drive system design. It depends 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 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 or dumps from the motor with a change in voltage. Size the bulk capacitance to meet acceptable voltage ripple levels.

The data sheet provides a recommended minimum value, but system-level testing is required to determine the appropriate-sized bulk capacitor.

Figure 13. Setup of Motor Drive System With External Power Supply