DRV2624 Datasheet, PDF (29/79 Pages) Texas Instruments – DRV2624 Ultra Low Power Closed-Loop LRA/ERM Haptic Driver with Internal Memory

www.ti.com
DRV2624
SLOS893A – DECEMBER 2015 – REVISED DECEMBER 2015
The following instructions list the step-by-step register configuration for auto-calibration.
1. Apply a valid supply voltage to the DRV2624 device, and then pull the NRST pin high. The supply voltage
should allow for adequate drive voltage of the selected actuator.
2. Write a value of 0x03 to the MODE parameter to set the auto-calibration routine.
3. Populate the input parameters required by the auto-calibration engine:
(a) LRA_ERM — selection will depend on desired actuator.
(b) FB_BRAKE_FACTOR[2:0] — A value of 3 is valid for most actuators.
(c) LOOP_GAIN[1:0] — A value of 2 is valid for most actuators.
(d) RATED_VOLTAGE[7:0] — See the Rated Voltage Programming section for calculating the correct
register value.
(e) OD_CLAMP[7:0] — See the Overdrive Voltage-Clamp Programming section for calculating the correct
register value.
(f) AUTO_CAL_TIME[1:0] — A value of 3 is valid for most actuators.
(g) DRIVE_TIME[3:0] — See the Drive-Time Programming for calculating the correct register value.
(h) SAMPLE_TIME[1:0] — A value of 3 is valid for most actuators.
(i) BLANKING_TIME[3:0] — A value of 1 is valid for most actuators.
(j) IDISS_TIME[3:0] — A value of 1 is valid for most actuators.
(k) ZC_DET_TIME[1:0] — A value of 0 is valid for most actuators.
4. Write a 1 to the GO bit to start the auto-calibration process. When auto calibration is complete, the GO bit
automatically clears. The auto-calibration results are written in the respective registers as shown in
Figure 28.
5. Check the status of the DIAG_RESULT bit to ensure that the auto-calibration routine is complete without
faults.
6. Evaluate system performance with the auto-calibrated settings. Note that the evaluation should occur during
the final assembly of the device because the auto-calibration process can affect actuator performance and
behavior. If any adjustment is required, the inputs can be modified and this sequence can be repeated. If the
performance is satisfactory, the user can do any of the following:
(a) Repeat the calibration process upon subsequent power ups.
(b) Store the auto-calibration results in host processor memory and rewrite them to the DRV2624 device
upon subsequent power ups. The device retains these settings when in STANDBY mode or when the EN
pin is low.
Copyright © 2015, Texas Instruments Incorporated
Product Folder Links: DRV2624
Submit Documentation Feedback
29