Datasheet
Table Of Contents
- General Description
- Key Features
- Applications
- System Diagrams
- Contents
- Figures
- Tables
- Legal
- Product Family
- 1 Terms and Definitions
- 2 Block Diagram
- 3 Pinout
- 4 Characteristics
- 5 Functional Description
- 5.1 Features Description
- Driving LRA and ERM Actuators
- Automatic LRA Resonant Frequency Tracking
- Wideband LRA Support
- I2C and PWM Input Streaming
- Low Latency I2C/GPI Wake-Up from IDLE State
- Three GPI Sequence Triggers for up to Six Independent Haptic Responses
- On-Board Waveform Memory with Amplitude, Time, and Frequency Control
- Active Acceleration and Rapid Stop for High-Fidelity Haptic Feedback
- Continuous Actuator Diagnostics and Fault Handling
- No Software Requirements with Embedded Operation
- Differential Output Drive
- Current Driven System
- Configurable EMI Suppression
- Automatic Short Circuit Protection
- Ultra-Low Power Consumption with State Retention
- Ultra-Low Latency in STANDBY State
- Supply Monitoring, Reporting, and Automatic Output Limiting
- Open- and Closed-Loop Modes
- Open-Loop Sine/Custom Wave Drive Support
- Small Solution Footprint
- Additional Features
- 5.2 Functional Modes
- 5.3 Resonant Frequency Tracking
- 5.4 Active Acceleration and Rapid Stop
- 5.5 Wideband Frequency Control
- 5.6 Device Configuration and Playback
- 5.7 Advanced Operation
- 5.7.1 Frequency Tracking
- 5.7.2 Rapid Stop
- 5.7.3 Initial Impedance Update
- 5.7.4 Amplitude PID
- 5.7.5 Wideband Operation
- 5.7.6 Custom Waveform Operation
- 5.7.7 Embedded Operation
- 5.7.8 Polarity Change Reporting for Half-Period Control in DRO Mode
- 5.7.9 Loop Filter Configuration
- 5.7.10 UVLO Threshold
- 5.7.11 Edge Rate Control
- 5.7.12 Double Output Current Range
- 5.7.13 Supply Monitoring, Reporting, and Automatic Output Limiting
- 5.7.14 BEMF Fault Limit
- 5.7.15 Increasing Impedance Detection Accuracy
- 5.7.16 Frequency Pause during Rapid Stop
- 5.7.17 Frequency Pause during Rapid Stop
- 5.7.18 Coin ERM Operation
- 5.8 Waveform Memory
- 5.9 General Data Format
- 5.10 I2C Control Interface
- 5.1 Features Description
- 6 Register Overview
- 7 Package Information
- 8 Ordering Information
- 9 Application Information
- 10 Layout Guidelines
DA7280
LRA/ERM Haptic Driver with Multiple Input Triggers,
Integrated Waveform Memory and Wideband Support
Datasheet
Revision 3.0
30-Jul-2019
CFR0011-120-00
35 of 76
© 2019 Dialog Semiconductor
variation for increased voltage accuracy of the drive. The result is reported to IMPEDANCE_H/L,
which can be read by the host and converted to impedance using the following formula:
(12)
To disable this feature, set V2I_FACTOR_FREEZE and CALIB_IMPEDANCE_DIS = 1.
5.7.4 Amplitude PID
Some cylinder based ERMs generate excessively large-amplitude BEMF voltages. DA7280 can
compensate for this by reducing the drive current level, set AMP_PID_EN = 1. The result is an
improved haptic response. Figure 17 describes how the actuator voltage and current differs when
AMP_PID_EN enabled or disabled.
Time [s]
Output Voltage
Envelope [V]
V
OUT
I
OUT
AMP_PID_EN = 0
Time [s]
Output Current
Envelope [A]
BEMF Voltage
Time [s]
Output Voltage
Envelope [V]
V
OUT
I
OUT
AMP_PID_EN = 1
Time [s]
Output Current
Envelope [A]
I
OUT
drops automatically to compensate
BEMF and keep V
OUT
constant
Figure 17: Output Voltage and Current for Different AMP_PID_EN Values
Note: This is not usually required for LRAs as the amplitude of the BEMF is typically very low.
5.7.5 Wideband Operation
DA7280 natively supports wideband LRAs and allows continuous frequency updates to the output
signal while driving. Amplitude and frequency data use parallel data paths, for configuration see
Section 5.6.5. This section describes how to use the frequency component only.
For wideband operation, frequency tracking must be disabled, by setting FREQ_TRACK_EN = 0,
because drive at frequencies different from the actuator resonant frequency is required. Rapid Stop
and Active Acceleration also rely on frequency tracking so must be deactivated by setting
ACCELERATION_EN = 0 and RAPID_STOP_EN = 0. There are two ways to operate DA7280 during
wideband operation:
● In the limited frequency range of 25 Hz to 300 Hz:
○ No further settings are required in RTWM and ETWM modes if the frequency information is
already stored in the Waveform Memory frame data as described in Section 5.8.3. If the
Waveform Memory does not contain frequency information, then each sequence can be
played at a different frequency by setting LRA_PER_H and LRA_PER_L to the desired value
via the formulae in Section 5.6.2 before triggering playback using the method described in
Sections 5.6.5.4 and 5.6.5.5.
○ In the DRO and PWM modes, the frequency information can be updated via the LRA_PER_H
and LRA_PER_L using the formulae in Section 5.6.2 either before triggering playback of
each sequence, see Sections 5.6.5.2 and 5.6.5.3, or during the playback itself. As with
amplitude, the one half-period uncertainty on the output frequency update also applies.
● In the full range of 25 Hz to 1024 Hz, the same procedures apply for all modes, but the following
registers need to be set:
○ BEMF_SENSE_EN = 0
○ DELAY_H = 0
○ DELAY_SHIFT_L = 0
○ DELAY_FREEZE = 1