SLOS825E December 2012 – April 2018 DRV2605
During closed-loop operation, the actuator feedback allows the output voltage go above the rated voltage during the automatic overdrive and automatic braking periods. The OD_CLAMP[7:0] bit (in Register 0x17) sets a clamp so that the automatic overdrive is bounded. The OD_CLAMP[7:0] bit also serves as the full-scale reference voltage for open-loop operation. The OD_CLAMP[7:0] bit always represents the maximum peak voltage that is allowed, regardless of the mode.
If the supply voltage (VDD) is less than the overdrive clamp voltage, the output driver is unable to reach the clamp voltage value because the output voltage cannot exceed the supply voltage. If the rated voltage exceeds the overdrive clamp voltage, the overdrive clamp voltage has priority over the rated voltage.