DRV2625 Datasheet, PDF (17/77 Pages) Texas Instruments – DRV2625 Ultra Low Power Closed-Loop LRA/ERM Haptic Driver with Built-In Library

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DRV2625
SLOS879A – DECEMBER 2015 – REVISED DECEMBER 2015
8.3.12.3 VDD UVLO Protection
The DRV2625 device has a battery monitor that monitors the VDD level to ensure that is above a configurable
threshold (using UVLO_THRES[2:0] parameter).
In the event of a VDD droop, the DRV2625 device immediately goes into standby state to reduce current
consumption and latches the UVLO flag (UVLO bit).
If the interrupt functionality is selected in the TRIG_PIN_FUNC parameter and the interrupt is not masked, and
interrupt will be fired to alert the host processor of a critical condition.
8.3.12.4 Brownout Protection
The DRV2625 device has on-chip brownout protection. When activated, a reset signal is issued that returns the
DRV2625 device to the initial default state. If the regulator voltage V_(REG) goes below the brownout protection
threshold (V_(BOT)) the DRV2625 device automatically shuts down. When V_(REG) returns to the typical output
voltage (1.8 V) the DRV2625 device returns to the initial device state. The brownout protection threshold (V_(BOT))
is typically at 1.6 V.
8.3.13 POR
The POR circuit was designed to enable the device only when both VDD and REG voltages are at a healthy
level. If REG voltage level were to dip below the reset threshold, the device will automatically abort any process
and shutdown until appropriate power levels are available, once a valid voltage is present in both VDD and REG
nodes, the device will proceed with the power-up sequence and return to the default state. If VDD drops below
UVLO with VREG still at a healthy level, the device will immediately go into standby state.
8.3.14 Silicon Revision Control
The DRV2625 has a revision control implemented in CHIPID[3:0] and REV[3:0] parameter (located in register
0x00). This feature allows an external controller to determine which device is connected to it and select the
appropriate firmware to control the device, which makes firmware development easier to port from one platform
to another.
8.3.15 Support for LRA and ERM Actuators
The DRV2625 device supports both LRA and ERM actuators. The default state is LRA mode, but can be
changed by using the LRA_ERM bit.
8.3.16 Multi-Purpose Pin Functionality
To enhance the flexibility of the DRV2625, the TRIG/INTZ pin is a configurable, multi-purpose pin that takes
different functionality depending on the mode of operation. The pin can serve as an input trigger-pulse pin, as an
input trigger-level (enable) pin and as an output interrupt pin. Note that the TRIG/INTZ pin can only execute one
function at a time (either trigger-edge, trigger-level (enable) or interrupt function), therefore if a particular function
is selected (for example, TRIG/INTZ configured as input trigger-edge), then the other functionality will not be
available (for example, interrupt).
8.3.16.1 Trigger-Pulse Functionality
The trigger-pulse functionality allows for an external processor to initiate the process (either waveform
sequencer, RTP, diagnostics or calibration) by pulsing the TRIG/INTZ pin. The process will initiate and play until
it is done, at which point it will go back into standby mode to preserve power. If a stop trigger (another trigger-
pulse) is received before the routine has finished, the routine will stop and the device will go back into standby
state. In the case of diagnostics mode, a stop trigger causes the diagnostic routine to abort and no result will be
reported. In the case of automatic level calibration routine, a stop trigger will cause the calibration to abort unless
the AUTO_CAL_TIME[2:0] is set to trigger control, in which case the stop trigger is required for the calibration to
complete, and the calibration will graciously finish and provide the expected output. Also note that a stop trigger
can also be achieved by writing 0 to the GO bit.
The minimum pulse width duration is 1 µs.
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