Texas Instruments DRV2605EVM-CT Datenbogen
Auto-calibration engine
ERM_LRA
FB_BRAKE_FACTOR[2:0]
LOOP_GAIN[1:0]
RATED_VOLTAGE[7:0]
BEMF_GAIN[1:0]
A_CAL_COMP[7:0]
A_CAL_BEMF[7:0]
DIAG_RESULT
OD_CLAMP[7:0]
AUTO_CAL_TIME[1:0]
DRIVE_TIME[4:0]
SAMPLE_TIME[1:0]
BLANKING_TIME[1:0]
IDISS_TIME[1:0]
LRA
only
Inputs
Outputs
SLOS825C – DECEMBER 2012 – REVISED SEPTEMBER 2014
Programming (continued)
7.5.4 Programming for Open-Loop Operation
The DRV2605 device can be used in open-loop mode and closed-loop mode. If open-loop operation is desired,
the first step is to determine which actuator type is to use, either ERM or LRA.
the first step is to determine which actuator type is to use, either ERM or LRA.
7.5.4.1 Programming for ERM Open-Loop Operation
To configure the DRV2605 device in ERM open-loop operation, the ERM must be selected by writing the
N_ERM_LRA bit to 0 (in register 0x1A), and the ERM_OPEN_LOOP bit to 1 in register 0x1D.
N_ERM_LRA bit to 0 (in register 0x1A), and the ERM_OPEN_LOOP bit to 1 in register 0x1D.
7.5.4.2 Programming for LRA Open-Loop Operation
To configure the DRV2605 device in LRA open-loop operation, the LRA must be selected by writing the
N_ERM_LRA bit to 1 in register 0x1A, and the LRA_OPEN_LOOP bit to 1 in register 0x1D.
N_ERM_LRA bit to 1 in register 0x1A, and the LRA_OPEN_LOOP bit to 1 in register 0x1D.
7.5.5 Programming for Closed-Loop Operation
For closed-loop operation, the device must be calibrated according to the actuator selection. When calibrated
accordingly, the user only needs to provide the desired waveform. The DRV2605 device automatically adjusts
the level and, for the LRA, automatically adjusts the driving frequency.
accordingly, the user only needs to provide the desired waveform. The DRV2605 device automatically adjusts
the level and, for the LRA, automatically adjusts the driving frequency.
7.5.6 Auto Calibration Procedure
The calibration engine requires a number of bits as inputs before it can be executed (see
). When the
inputs are configured, the calibration routine can be executed. After calibration execution occurs, the output
parameters are written over the specified register locations.
parameters are written over the specified register locations.
shows all of the required inputs and
generated outputs. To ensure proper auto-resonance operation, the LRA actuator type requires more input
parameters than the ERM. The LRA parameters are ignored when the device is in ERM mode.
parameters than the ERM. The LRA parameters are ignored when the device is in ERM mode.
Figure 23. Calibration-Engine Functional Diagram
Variation occurs between different actuators even if the actuators are of the same model. To ensure optimal
results, TI recommends that the calibration routine be run at least once for each actuator. The OTP feature of the
DRV2605 device can store the calibration values. Because of these stored values, the calibration procedure
does not have run every time. Having a single set of calibration register values that can be loaded during the
system initialization is possible.
results, TI recommends that the calibration routine be run at least once for each actuator. The OTP feature of the
DRV2605 device can store the calibration values. Because of these stored values, the calibration procedure
does not have run every time. Having a single set of calibration register values that can be loaded during the
system initialization is possible.
24
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