Data Sheet

Supply
correction
I
2
C I/F
REG
Back-EMF
detection
ROM
Gate
drive
Gate
drive
Control and
playback
engine
M
LRA
or
ERM
OUT±
OUT+
GND
REG
IN/TRIG
SDA
SCL
EN
V
DD
DRV2605L
SLOS854C –MAY 2014–REVISED SEPTEMBER 2014 www.ti.com
8 Detailed Description
8.1 Overview
The DRV2605L device is a low-voltage haptic driver that relies on the back-EMF produced by an actuator to
provide a closed-loop system that offers extremely flexible control of LRA and ERM actuators over a shared I
2
C-
compatible bus or PWM input signal. This schema helps improve actuator performance in terms of acceleration
consistency, start time, and brake time.
The improved smart-loop architecture inside the DRV2605L device provides effortless auto-resonant drive for
LRA, as well as feedback-optimized ERM drive allowing for automatic overdrive and braking. These features
create a simplified input waveform paradigm as well as reliable motor control and consistent motor performance.
The DRV2605L device also features automatic transition to open-loop operation in the event that an LRA
actuator is not generating a valid back-EMF voltage and automatic synchronization with the LRA when it is
generating a valid back-EMF voltage. The DRV2605L device also allows for open-loop driving by using internally-
generated PWM. Additionally, the audio-to-vibe mode automatically converts an audio input signal to meaningful
haptic effects.
The DRV2605L device offers a licensed version of TouchSense 2200 software from Immersion which eliminates
the need to design haptic waveforms because the software includes over 100 licensed effects (6 ERM libraries
and 1 LRA library) and audio-to-vibe features. These waveforms can be instantly played back through an I
2
C or
can be triggered through a hardware trigger pin. Additionally, the real-time playback mode allows the host
processor to bypass the library playback engine and play waveforms directly from the host through the I
2
C.
The DRV2605L device features a trinary-modulated output stage that provides more efficiency than linear-based
output drivers.
8.2 Functional Block Diagram
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Product Folder Links: DRV2605L