US Patent 10219344 Light emitting diode driver for dimming and on/off control

In one aspect, an integrated circuit (IC) includes a first magnetic field sensor configured to sense a ring magnet, a second magnetic field sensor configured to sense the ring magnet and processing circuitry configured to receive a first signal from the first magnetic field sensor and to receive a second signal from the second magnetic field sensor. The processing circuitry is further configured to control an on/off state of at least one light emitting diode (LED) and brightness of the LED based on movement and position of the ring magnet with respect to the first and second magnetic field sensors.