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
17 of 76
© 2019 Dialog Semiconductor
voltage polarity. This doubles the voltage swing across the actuator and significantly increases
system efficiency relative to a single transistor/LDO solution in legacy ERM or LRA applications.
Current Driven System
The device outputs regulated current, rather than voltage, which allows BEMF tracking without the
need to stop driving to sense the BEMF. This maximizes power delivery to the actuator per unit time
when compared to voltage driven solutions, resulting in shorter and sharper haptic clicks. In addition,
constant current drive provides constant force into an actuator independently of the BEMF amplitude.
Configurable EMI Suppression
Switching node edge rate control (ERC) on the OUTP and OUTN pins reduces electromagnetic
interference (EMI) and electrical interference via capacitive coupling in the end application, see
Section 5.7.11. This eliminates any need for resistor-capacitor (RC) or ferrite bead filtering of the
outputs, which offers a lower-cost bill of materials when using DA7280. Programmability of the ERC
also gives DA7280 a distinct advantage over competing solutions as it helps fine-tune a system
without any PCB modifications.
Automatic Short Circuit Protection
Automatic low-latency short circuit protection detects shorts on the OUTP and OUTN pins to supply,
ground, or between OUTP and OUTN, and protects DA7280 by forcing the H-bridge into a high-
impedance state, see Section 5.6.6.
Ultra-Low Power Consumption with State Retention
In IDLE state, DA7280 has an ultra-low current consumption from the power supply at typically
0.36 µA with a time to output of 0.75 ms. DA7280 returns automatically to IDLE after completing
playback, keeps its internal state, and is available for I
2
C communications, see Section 5.2.1.
Ultra-Low Latency in STANDBY State
In STANDBY state, the time to output is 0.15 ms with current consumption of typically 0.8 mA, see
Section 5.2.1.
Supply Monitoring, Reporting, and Automatic Output Limiting
DA7280 monitors the power supply voltage level and adjusts the drive voltage accordingly, so that
the output does not clip to the supply voltage. This feature guarantees controlled output allowing
continued resonant frequency tracking and Active Acceleration/Rapid Stop functionality even when
the device is operating under low power supply conditions or heavy battery load. Supply voltage can
be read back by the host from a dedicated register, see Section 5.7.13.
Open- and Closed-Loop Modes
DA7280 can be configured in either open- or closed-loop mode. In open-loop mode any actuator
BEMF monitoring is disabled and the device works as a simple current based drive without any auto-
adjustment on the drive period or amplitude. This is useful in wideband LRA playback. In closed-loop
mode, the user can optionally turn on the frequency tracking, Active Acceleration, Rapid Stop, and
amplitude control features, see Section 5.7.5 and Section 5.7.6.
Open-Loop Sine/Custom Wave Drive Support
In open-loop operation DA7280 can be configured to drive the actuator with a non-square wave
signal. This improves the electrical efficiency, reduces audibility in some actuators, and allows
simultaneous drive of multiple resonant points in DMAs. The exact shape of the output waveform can
be configured via dedicated registers with the default set to a sine wave, see Section 5.7.6.