Application recommendations

VN770KP-E

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DocID022021 Rev 4

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Application recommendations

Figure 44. Application diagram bridge drivers

Most motor bridge drivers use a reverse battery protection diode (D) inside the supply rail.

This diode prevents a reverse current flow back to VBATT in case the bridge becomes

disabled via the logic inputs while motor inductance still carries energy. In order to prevent a

hazardous overvoltage at circuit supply terminal (VCC), a blocking capacitor (C) is needed to

limit the voltage overshoot. As basic orientation, 50 μF per 1 A load current is

recommended. As an alternative, a Zener protection (Z) is also suitable.

Even if a reverse polarity diode is not present, it is recommended to use a capacitor or

Zener at VCC because a similar problem appears in case the supply terminal of the module

has intermittent electrical contact to the battery or gets disconnected while the motor is

operating.