SLOS825E December 2012 – April 2018 DRV2605
In open-loop mode, the reference level for full-scale drive is set by the OD_CLAMP[7:0] bit in Register 0x17. A mid-scale input value gives no drive signal, and a less-than mid-scale gives a negative drive value. For an ERM, a negative drive value results in counter-rotation, or braking. For an LRA, a negative drive value results in a 180-degree phase shift in commutation.
The RTP mode has 8 bits of resolution over the I2C bus. The RTP data can either be in a signed (2s complement) or unsigned format as defined by the DATA_FORMAT_RTP bit.