Patent attributes
An integrated circuit (IC) chip for driving a mass of a linear resonant actuator (LRA) using low-latency closed-loop control is described. The IC chip includes class-D amplifier circuitry configured to provide to coils of the LRA, a driving signal, which has a pulse-width modulation configured to control a position of the mass as a function of time. The driving signal has a frequency in a range of 10-100 kH, and the pulse-width modulation has a bandwidth smaller than 1 kHz. The IC chip also includes class-D controller circuitry configured to process (i) a position-monitoring signal, which (a) is received from position sensors of the LRA and (b) corresponds to the position of the mass, and (ii) a drive-monitoring signal, which relates to the driving signal, to obtain a digital driving signal. The class-D amplifier circuit is configured to amplify the digital driving signal to obtain the analog driving signal.
