DRV2604L Datasheet, PDF (18/73 Pages) Texas Instruments – DRV2604L 2- to 5.2-V Haptic Driver for LRA and ERM with Internal Memory and Smart-Loop Architecture

DRV2604L
SLOS866D – MAY 2014 – REVISED JUNE 2015
Feature Description (continued)
Level Trigger
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Haptic Waveform
Level Trigger
Cancellation
Haptic Waveform
Figure 14. Level Trigger Mode
8.3.5.6 Noise Gate Control
When an actuator is driven with an analog or PWM signal, noise in the line can cause the actuator to vibrate
unintentionally. For that reason, the DRV2604L device features a noise gate that filters out any voltage smaller
than a particular threshold. The NG_THRESH[1:0] bit in register 0x1D controls the threshold.
8.3.6 Edge Rate Control
The DRV2604L output driver implements edge rate control (ERC). The ERC ensures that the rise and fall
characteristics of the output drivers do not emit levels of radiation that could interfere with other circuitry common
in mobile and portable platforms. Because of ERC most system do not require external output filters, capacitors,
or ferrite beads.
8.3.7 Constant Vibration Strength
The DRV2604L PWM input uses a digital level-shifter. Therefore, as long as the input voltage meets the V_IH and
V_IL levels, the vibration strength remains the same even if the digital levels vary. The DRV2604L device also
features power-supply feedback. If the supply voltage drifts over time (because of battery discharge, for
example), the vibration strength remains the same as long as enough supply voltage is available to sustain the
required output voltage.
8.3.8 Battery Voltage Reporting
During playback, the DRV2604L device provides real-time voltage measurement of the V_DD pin. The VBAT[7:0]
bit located in register 0x21 provides this information.
8.3.9 One-Time Programmable (OTP) Memory for Configuration
The DRV2604L device contains nonvolatile, on-chip, OTP memory for specific configuration parameters. When
written, the DRV2604L device retains the device settings in registers 0x16 through 0x1A including after power
cycling. This retention allows the user to account for small variations in actuator manufacturing from unit to unit
as well as to shorten the device-initialization process for device-specific parameters such as actuator type,
actuator-rated voltage, and other parameters. An additional benefit of OTP is that the DRV2604L memory can be
customized at the device-test level without driving changes in the device software.
8.3.10 Low-Power Standby
Setting the device to standby reduces the idle power consumption without resetting the registers. In Low-Power
Standby mode, the DRV2604L device features a fast turnon time when it is requested to play a waveform.
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