DA7281 LRA/ERM Haptic Driver with Multiple IC Addresses, Integrated Waveform Memory, and Wideband Support General Description DA7281 is a linear resonant actuator (LRA) and eccentric rotating mass (ERM) haptic driver offering automatic closed-loop LRA resonant frequency tracking. The feature guarantees consistency across LRA production tolerances, operating temperature, aging, and mechanical coupling. DA7281 offers wideband operation that fully utilizes the capabilities of newer wideband and multi-directional LRAs. The differential output drive architecture and continuous actuator motion sensing enable efficient, calibration-free playback and minimize software complexity. Featuring wake-up on General Purpose 2 Input (GPI) sequence trigger and/or I C activity, DA7281 automatically returns to a low quiescent current state (typically 0.36 A) between playbacks. At only 20 % of the idle current of the nearest alternative solution, DA7281 significantly extends battery life in mobile systems. To reduce system complexity, an integrated Waveform Memory allows haptic sequences to be pre- loaded to DA7281. Independent sequences can be triggered, with low-latency (0.75 ms), by the GPI pin without host interaction. Haptic sequences can also be streamed to DA7281 from an external 2 source via I C or pulse width modulated (PWM) signal. DA7281 actively monitors the back electromotive force (BEMF) while continuously driving and applies closed-loop Active Acceleration and Rapid Stopping for sharper clicks and a higher fidelity user experience. This offers significant advantages over existing solutions that need to move into a high-impedance state during drive to measure the BEMF, which adds a considerable amount of inactive time to the sequence and lowers the effective click strength for a given LRA. Key Features 2 LRA or ERM drive capability Up to four I C addresses via two address pins Automatic LRA resonant frequency tracking No software requirements with embedded operation Wideband LRA support Differential PWM output drive 2 I C and PWM input streaming Current driven system to deliver constant 2 Low latency (0.75 ms) I C/GPI wake-up actuator power from low power consumption IDLE state, I = 0.36 A Configurable EMI suppression Q Ultra-low latency (0.15 ms) wake-up from Automatic short circuit protection STANDBY state, I = 0.8 mA Q Ultra-low power consumption, I = 0.36 A, Q GPI pin for triggering of up to two independent with state retention in IDLE state haptic sequences Supply monitoring, reporting, and automatic On-board Waveform Memory with amplitude, output limiting time, and frequency control Open- and closed-loop modes Active Acceleration and Rapid Stop Custom wave drive support technology for high-fidelity haptic feedback Small solution footprint requiring only one Actuator diagnostics and fault handling decoupling capacitor in both WLCSP and QFN VDDIO VDD Over- SCL Applications 2 Battery I C References Temperature Monitor SDA Protection Smartphones, wearables, and hearables nIRQ BEMF Sensing and Actuator Diagnostics Resonant Computer peripherals Frequency OUTP Tracking, ERC Driver Gaming Active Acceleration, ADDR 0 Short Circuit LRA/ Automotive and industrial Rapid Stop, Protection ERM and ADDR 1 Virtual and augmented reality controllers Waveform ERC Driver Memory OUTN GPI/PWM DA7281 GND Datasheet Revision 3.0 30-Jul-2019 CFR0011-120-00 1 of 76 2019 Dialog Semiconductor Regulation Loop DA7281 LRA/ERM Haptic Driver with Multiple IC Addresses, Integrated Waveform Memory, and Wideband Support System Diagrams VDDIO VBAT VDDIO VBAT VDDIO VDD VDDIO VDD OUTP OUTP SDA SDA SCL SCL nIRQ nIRQ LRA/ LRA/ Host DA7281 ERM Host DA7281 ERM GPI/PWM GPI/PWM ADDR 0 OUTN ADDR 0 OUTN ADDR 1 ADDR 1 GND GND 2 2 GPI and I C I C Only Direct Address Control from Host Address Set in Hardware VDDIO VBAT VDDIO VBAT VDDIO VDD VDDIO VDD OUTP OUTP SDA SDA SCL SCL nIRQ nIRQ LRA/ LRA/ Host Host DA7281 ERM DA7281 ERM GPI/PWM GPI/PWM ADDR 0 OUTN ADDR 0 OUTN ADDR 1 ADDR 1 GND GND Embedded Operation PWM Only Address Set in Hardware Address Set in Hardware VBAT External Boost VBST up to 5.5V VBAT VDDIO VDDIO VDDIO VDD VDDIO VDD OUTP OUTP Host SDA SDA (startup SCL SCL only) nIRQ nIRQ LRA/ LRA/ Host Sensor DA7281 ERM DA7281 ERM Hub or Button GPI/PWM GPI/PWM Press ADDR 0 ADDR 0 OUTN OUTN Detect ADDR 1 ADDR 1 GND GND Embedded Operation External Boost No Host Operation Figure 1: System Diagrams Datasheet Revision 3.0 30-Jul-2019 CFR0011-120-00 2 of 76 2019 Dialog Semiconductor