SLOS879C April 2014 – June 2025 DRV2625
PRODUCTION DATA
A key feature of the DRV2625 is the smart-loop architecture which employs actuator feedback control for both ERMs and LRAs. The feedback control desensitizes the input waveform from the motor-response behavior by providing automatic overdrive and automatic braking.
An open-loop haptic system typically drives an overdrive voltage at startup that is higher than the steady-state rated voltage of the actuator to decrease the startup latency of the actuator. Likewise, a braking algorithm must be employed for effective braking. When using an open-loop driver, these behaviors must be contained in the input waveform data. Consider the example of an ERM actuator of Motor A and another of Motor B. The input waveform in open loop is different (see Figure 7-1). In contrast, by using the smart-loop technology with automatic overdrive and braking, the same input waveform works for both actuators (see Figure 7-2). The smart-loop architecture works equally well for LRAs with a combination of feedback control and an auto-resonance engine.
Figure 7-1 Typical Open Loop Waveform
Figure 7-2 Waveform Simplification With Smart Loop