RENESAS DA7281-00V4C

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 Input (GPI) sequence trigger and/or two's complement activity, DA7281 automatically returns to a low quiescent current state (typically 0.36 μA) 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 preloaded 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 source via I²C 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.

• LRA or ERM drive capability
• Automatic LRA resonant frequency tracking
• Wideband LRA support I²C and PWM input streaming
• Low latency (0.75 ms) I²C/GPI wake-up from low power consumption IDLE state, I_Q = 0.36 μA
• Ultra-low latency (0.15 ms) wake-up from STANDBY state, I_Q = 0.8 mA
• GPI pin for triggering of up to two independent haptic sequences
• On-board Waveform Memory with amplitude, time, and frequency control
• Active Acceleration and Rapid Stop technology for high-fidelity haptic feedback
• Actuator diagnostics and fault handling
• Up to four I²C addresses via two address pins
• No software requirements with embedded operation
• Differential PWM output drive
• Current driven system to deliver constant actuator power
• Configurable EMI suppression
• Automatic short circuit protection
• Ultra-low power consumption, I_Q = 0.36 μA, with state retention in IDLE state
• Supply monitoring, reporting, and automatic output limiting
• Open- and closed-loop modes
• Custom wave drive support
• Small solution footprint requiring only one decoupling capacitor in both WLCSP and QFN

• Smartphones, wearables, and hearables
• Computer peripherals
• Gaming
• Automotive and industrial
• Virtual and augmented reality controllers