SLOS893D September 2014 – August 2025 DRV2624
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
The resonance frequency of each LRA actuator varies based on many factors and is generally dominated by mechanical properties. The auto-resonance engine-tracking system is optimized by providing information about the resonance frequency of the actuator. The DRIVE_TIME[4:0] bit is used as an initial guess for the half-period of the LRA. The drive time is automatically and quickly adjusted for optimum drive. For example, if the LRA has a resonance frequency of 200Hz, then the drive time is set to 2.5ms.
For ERM actuators, the DRIVE_TIME[4:0] bit controls the rate for back-EMF sampling. Lower drive times imply higher back-EMF sampling frequencies which cause higher peak-to-average ratios in the output signal, and requires more supply headroom. Higher drive times imply lower back-EMF sampling frequencies which cause the feedback to react at a slower rate.