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
26 of 76
© 2019 Dialog Semiconductor
(4)
(5)
(6)
– Where V2I_FACTOR[15:0] is the 16-bit concatenation of V2I_FACTOR_H[7:0] and
V2I_FACTOR_L[7:0], Z is the impedance of the actuator in Ω (as read from its datasheet),
and IMAX[4:0] is the 5-bit value of IMAX.
6. Program the LRA resonant frequency in terms of period by updating LRA_PER_H and
LRA_PER_L based on the following formula:
(7)
(8)
(9)
– Where LRA
freq
represents the LRA resonant frequency in Hz, as listed in the actuator
datasheet.
Note: For ERM this value will signify the frequency of BEMF sensing; if more frequent updates are
required, the value can be increased up to 300 Hz.
For driving coin ERMs, see Section 5.7.18.
5.6.3 Automatic Output Control
DA7280 has several automatic control loops and mechanisms to ensure excellent playback fidelity
and easy actuator setup:
● Automatic frequency tracking - this feature allows resonant frequency tracking during playback
and is enabled via FREQ_TRACK_EN. Frequency tracking must be enabled to use the Active
Acceleration and Rapid Stop features. For fine-tuning the frequency tracking loop, see Section
5.7.1.
● Active Acceleration - this feature improves playback fidelity by overdriving and underdriving the
actuator to allow faster transitions between acceleration levels. This improves on the inherent
actuator mechanical time constant. To enable Active acceleration set ACCELERATION_EN = 1.
Note that the input data is interpreted as either unsigned (ACCELERATION_EN = 0) or signed
(ACCELERATION_EN = 1). For more detail on data formatting, see Section 0.
● Rapid Stop - this is a mechanism to allow the fastest possible stop to zero acceleration output for
the actuator. DA7280 achieves this by driving in full reverse the actuator by applying a 180°
phase shift in the case of an LRA or inverting the voltage across the actuator in the case of an
ERM actuator. For fine-tuning the Rapid Stop feature, see Section 5.7.2.