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
38 of 76
© 2019 Dialog Semiconductor
The timing of the sequence can be described as follows in Figure 20 where Amplitude X denotes
consecutive different output drive values:
Time [s]
Output Voltage
Envelope [V]
OUTP
OUTN
POLARITY 0 01 1
OVERRIDE_VAL 0 31 4
I2C Update 1 32 4
2
Amplitude
0
Amplitude
3
Amplitude
1
Amplitude
2
Figure 20: Polarity Timing Relationship
5.7.9 Loop Filter Configuration
Haptic actuators (both ERM and LRA) can be modelled as a series combination of a resistor (Series
R) and inductor (Series L) followed by a BEMF voltage source, see Figure 21.
R
SERIES
L
SERIES
BEMF
O
Figure 21: Equivalent Electrical Model of an Actuator
The usual variation of R
SERIES
is from 8 Ω to 50 Ω and L
SERIES
is from 20 µH to either 2 mH or 3 mH.
The current regulation loop in the output drive must be kept stable by applying the correct setting in
the loop's filter. While the defaults cover the vast majority of available LRAs and ERMs further tuning
is possible by adjusting LOOP_FILT_CAP_TRIM, LOOP_FILT_RES_TRIM, and
LOOP_FILT_LOW_BW.
For LOOP_FILT_CAP_TRIM apply the settings in Table 15.
Table 15: LOOP_FILT_CAP_TRIM Register Trim Settings
Actuator Series Resistance (Ω)
Register
< 18
18 to 28
28 to 41
> 41
LOOP_FILT_CAP_TRIM
3
2
1
0