Modulation engine for dimming control
AssigneeInfineon Technologies AG
InventorsFabrizio Cortigiani, Maurizio Galvano
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Abstract
A modulation engine for a light-emitting-diode (LED) driver is described that includes an output port, a charge current source, a discharge current source, and an output control unit. The output control unit is configured to generate a modulation signal (e.g., a pulse-width-modulation signal) at the output port by at least alternating, based on a duty cycle of the modulation signal, between coupling the charge current source to the output port and the discharge current source to the output port to linearly shape the charge at the output port in accordance with the duty cycle.
Claims14
A modulation engine for a light-emitting-diode (LED) driver comprising:
- an output port;
- a charge current source;
- a discharge current source;
- and
- an output control unit that is configured to generate a modulation signal at the output port by at least alternating, based on a duty cycle of the modulation signal, between coupling the charge current source to the output port and the discharge current source to the output port to linearly shape the charge at the output port in accordance with the duty cycle, wherein the duty cycle of the modulation signal is defined by a ratio between either:
- a difference between a second resistance of the discharge current source and a first resistance of the charge current source and the first resistance of the charge current source;
- or
- the second resistance of the discharge current source and a sum of the first resistance of the charge current source and the second resistance of the discharge current source.
A system comprising:
- a light emitting diode (LED) driver configured to receive a modulation signal at an input of the LED driver;
- and
- a modulation engine comprising a charge current source and a discharge current source, the modulation engine being configured to generate the modulation signal at the input of the LED driver by at least alternating, based on a duty cycle of the modulation signal, between charging the input of the LED driver and discharging the input of the LED driver to linearly shape a charge at the input of the LED driver in accordance with the duty cycle of the modulation signal, wherein the duty cycle of the modulation signal is defined by a ratio between either:
- a difference between a second resistance of the discharge current source and a first resistance of the charge current source and the first resistance of the charge current source;
- or
- the second resistance of the discharge current source and a sum of the first resistance of the charge current source and the second resistance of the discharge current source.
A system comprising:
- means for generating a modulation signal at an input of a driver of one or more light emitting diode (LED) devices;
- and
- means for alternating, based on a duty cycle of the modulation signal, between charging the input of the driver with a charging current source and discharging the input of the driver with a discharging current source to linearly shape a charge at the input of the driver in accordance with the duty cycle of the modulation signal, wherein the duty cycle of the modulation signal is defined by a ratio between either:
- a difference between a second resistance of the discharge current source and a first resistance of the charge current source and the first resistance of the charge current source;
- or
- the second resistance of the discharge current source and a sum of the first resistance of the charge current source and the second resistance of the discharge current source.
Dependencies are inferred from the claim text.