8.3.5.4 Analog Input Interface

When the DRV2604L device is in analog-input interface mode, the device accepts an analog voltage at the IN/TRIG pin. The DRV2604L device drives the actuator continuously in analog-input interface mode until the user sets the device to standby mode or to enter another interface mode. The reference voltage in standby mode is 1.8 V. Therefore, the 1.8-V reference voltage is interpreted as a 100% input value. A reference voltage of 0.9 V is interpreted as a 50% input value and a reference voltage of 0 V is interpreted as a 0% input value. The input value in standby mode is analogous to the duty-cycle percentage in PWM mode.

For the LRA, the DRV2604L automatically tracks the resonance frequency unless the LRA_OPEN_LOOP bit is set (in register 0x1D). If the LRA_OPEN_LOOP bit is set, the LRA is driven according to the open-loop frequency set in OL_LRA_PERIOD[6:0] bit in register 0x20.