×

Systems and methods for a hysteresis based driver using a LED as a voltage reference

  • US 9,485,814 B2
  • Filed: 01/04/2013
  • Issued: 11/01/2016
  • Est. Priority Date: 01/04/2013
  • Status: Active Grant
First Claim
Patent Images

1. A driver for one or more light emitting diodes (LEDs) that incorporates forward voltage of the one or more LEDs to provide hysteresis, the driver comprising:

  • a first input to receive an input voltage;

    a switch electrically coupled to the first input and electrically coupled to one or more light emitting diodes (LEDs), an output of the switch, when switched on, to provide voltage to the one or more LEDs;

    a current measurement component electrically coupled to the one or more LEDS, to measure current through the one or more LEDs based on forward voltage of the one or more LEDs;

    a hysteresis component comprising a comparator to receive as input the input voltage and a measurement of voltage based on the current measured by the current measurement component, wherein the hysteresis component comprises a feed forward resistor electrically coupled between a non-inverted input of the comparator and an output of the comparator, the non-inverted input of the comparator receiving the measurement of voltage based on the current;

    wherein the current measurement component is configured to measure changes to the current based on changes to the forward voltage of the one or more LEDs; and

    wherein the hysteresis component is electrically coupled to the switch to turn the switch off and on responsive to changes to the input voltage in conjunction with the changes to the forward voltage of the one or more LEDs, as measured by the current measurement component, being above or below a threshold.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×