Datasheet
DRV2605
SLOS825C –DECEMBER 2012 –REVISED SEPTEMBER 2014
www.ti.com
The time values are additive offsets and are 8-bit signed values. The default offset of these values is 0. Positive
values add and negative values subtract from the time value of the effect that is currently played. The most
positive value in the waveform is automatically interpreted as the overdrive time, and the most negative value in
the waveform is automatically interpreted as the brake time. These time-offset parameters are applied to both
voltage-time pairs and linear ramps. For linear ramps, linear interpolation is stretched (or shrunk) over the two
operative points for the period (see Equation 1).
t + t
(ofs)
where
• t
(ofs)
is the time offset which is one of the previously listed time parameters (1)
Changing the playback interval can also manipulate the waveforms stored in memory. Each waveform in memory
has a granularity of 5 ms.
7.3.5.3 Real-Time Playback (RTP) Interface
The real-time playback mode is a simple, single 8-bit register interface that holds an amplitude value. When real-
time playback is enabled, the real-time playback register is sent directly to the playback engine. This value is
played until the user sends the device to standby mode or removes the device from RTP mode. The RTP mode
operates exactly like the PWM mode except that the user enters a register value over the I
2
C rather than a duty
cycle through the input pin. Therefore, any API (application-programming interface) designed for use with a PWM
generator in the host processor can write the data values over the I
2
C rather than writing the data values to the
host timer. This ability frees a timer in the host while retaining compatibility with the original software.
For the LRA, the DRV2605 device automatically tracks the resonance frequency.
7.3.5.4 Analog Input Interface
When the DRV2605 device is in analog-input interface mode, it accepts an analog voltage at the IN/TRIG pin.
The DRV2605 device drives the actuator continuously in this mode until the user sets the device to standby
mode or to enter another interface mode. The reference voltage in this mode is 1.8 V. Therefore, the 1.8 V
reference voltage is interpreted as a 100% input value. A reference voltage of 0.9 V is interpreted as a 50% input
value and a reference voltage of 0 V is interpreted as a 0% input value. The input value in this mode is
analogous to the duty-cycle percentage in PWM mode.
For the LRA, the DRV2605 automatically tracks the resonance frequency.
7.3.5.5 Audio-to-Vibe Interface
The DRV2605 device features an audio-to-vibe mode that converts an audio input signal into meaningful haptic
effects using the Immersion audio-to-vibe technology. Audio-to-Vibe mode adds a vibratory bass extension to
portable devices which allows users to feel the audio and visual content. This mode is a key feature because it
allows for existing applications to include haptic sensations without requiring additional software drivers.
Additionally, event-driven audio effects generated within an operating system can be used to automatically
provide a product with haptic sensations. See the Waveform Playback Using Audio-to-Vibe Mode section for
details.
7.3.5.6 Input Trigger Option
The DRV2605 device includes continuous haptic modes (such as PWM and RTP mode) as well as triggered
modes (such as the internal memory interface). The haptic effects in the continuous haptic modes begin as soon
as the device enters the mode and stop when the device goes into standby mode or exits the continuous haptic
mode. For the triggered mode, the DRV2605 device has a variety of trigger options that are explained in this
section.
In these modes, the IN/TRIG pin provides external trigger control of the GO bit, which allows GPIO control to fire
ROM waveforms. This external trigger control can provide improved latencies in systems where a significant
delay exists between the desired effect time and the time a GO command can be sent over the I
2
C interface.
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