DRV2625 Datasheet, PDF (52/77 Pages) Texas Instruments – DRV2625 Ultra Low Power Closed-Loop LRA/ERM Haptic Driver with Built-In Library

DRV2625
SLOS879A – DECEMBER 2015 – REVISED DECEMBER 2015
www.ti.com
8.7.35 Address: 0x23
Figure 76. 0x23
7
NG_THRESH[0]
R/W-0
6
5
4
FB_BRAKE_FACTOR[2:0]
R/W-0
R/W-1
R/W-1
3
2
LOOP_GAIN[1:0]
R/W-0
R/W-1
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 38. Address: 0x23
1
0
BEMF_GAIN[1:0]
R/W-1
R/W-0
BIT FIELD
7 NG_THRESH
6-4 FB_BRAKE_FACTOR[2:0]
3-2 LOOP_GAIN[1:0]
1-0 BEMF_GAIN[1:0]
TYPE
R/W
R/W
R/W
R/W
DEFAULT DESCRIPTION
0
Output noise gate control. If the driver intends to drive a magnitude below the threshold
selected in this bit, the output driver will send 0 (no output).
0
4% of VDD.
1
8% of VDD.
3
Selects the feedback gain ratio between braking gain and driving gain. In general, it is desirable
to add additional feedback gain while braking so that the actuator will brake as quickly as
possible. Large ratios give less stable operation than lower ones. The advanced user may
choose to optimize this register. Otherwise, the default value should give good performance for
most actuators. This value should be set prior to running auto calibration.
0
1.
1
2.
2
3.
3
4.
4
6.
5
8.
6
16.
7
Removes feedback during braking (braking disabled).
1
Selects a loop gain for the feedback control. This sets how fast the loop tries to make the back-
EMF (and thus motor velocity) match the input signal level. Higher loop gain (faster settling)
options will give less stable operation than lower loop gain (slower settling). The advanced user
may choose to optimize this register. Otherwise, the default value should give good
performance for most actuators. This value should be set prior to running auto calibration.
0
Very Slow.
1
Slow.
2
Fast.
3
Very Fast.
2
Sets the analog gain of the back-EMF amplifier. This value is interpreted differently between
ERM mode and LRA mode. Auto calibration will automatically populate BEMF_GAIN with the
most appropriate value for the actuator. Note that a user may overwrite this value.
0
5x for LRA Mode, 0.34x for ERM Mode.
1
10x for LRA Mode, 1.05x for ERM Mode.
2
20x for LRA Mode, 1.82x for ERM Mode.
3
30x for LRA Mode, 4x for ERM Mode.
8.7.36 Address: 0x24
Figure 77. 0x24
7
6
5
4
3
RATED_VOLTAGE_CLAMP[7:0]
R/W-0
R/W-1
R/W-1
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
2
R/W-1
1
R/W-0
0
R/W-0
Table 39. Address: 0x24
BIT FIELD
TYPE DEFAULT DESCRIPTION
7-0 RATED_VOLTAGE_CLAMP[ R/W
7:0]
100 This parameter is to set a clamp for the steady state voltage provided by the driver. This clamp
is enforced after the overdrive section of the waveform. Note that if the OD_CLAMP is lower
than this parameter, the lower clamp will be applied. The same is true if the
BAT_LIFE_EXT_LVLx is triggered.
52
Submit Documentation Feedback
Product Folder Links: DRV2625
Copyright © 2015, Texas Instruments Incorporated