Phase controller apparatus and methods
AssigneeCypress Semiconductor Corporation
InventorsTakuya Kurishita, Yukisato Miyazaki
Life of this patent
Estimating the term…
Abstract
A phase controller includes a plurality of pulse width modulation (PWM) circuits, a plurality of switching devices, a computing unit, and a latency generator. The plurality of PWM circuits output pulse signals. The plurality of switching devices are coupled to the respective plurality of PWM circuits, and switch on and off based on the pulse signals. The computing unit calculates the pulse signals to be output from the plurality of PWM circuits, based on outputs of the plurality of switching devices. The latency generator generates latency in any of the pulse signals so that edge positions of the pulse signals output from the plurality of PWM circuits do not collide with each other, wherein the pulse signals change values at the edge positions.
Claims17
A phase controller comprising:
- a plurality of pulse width modulation (PWM) circuits configured to output pulse signals;
- a plurality of switching devices, each coupled to a corresponding one of the plurality of PWM circuits, configured to switch on and off based on the pulse signals;
- a computing unit configured to calculate a duty ratio of each pulse signal of the plurality of pulse signals to be output from the plurality of PWM circuits, based on outputs of the plurality of switching devices;
- and
- a latency generator configured to calculate a latency for at least one pulse signal of a plurality of pulse signals and provide the latency in one or more delayable units to the at least one pulse signal of the plurality of pulse signals such that no edge positions of the plurality of pulse signals output from the plurality of PWM circuits collide with each other, wherein the plurality of pulse signals change values at the edge positions, wherein the latency generator is configured to generate a table for each of the plurality of pulse signals, and wherein each table is configured to indicate positions of changing state of a corresponding pulse signal.
A light modulation system comprising:
- a plurality of light emitting diodes (LEDs);
- a plurality of pulse width modulation (PWM) circuits configured to output pulse signals;
- a plurality of drivers, each driver coupled to a corresponding PWM circuit of the plurality of PWM circuits and coupled to a corresponding LED of the plurality of LEDs, each driver, of the plurality of drivers, configured to switch the corresponding LED on and off based on a pulse signal;
- a computing unit configured to calculate a duty ratio of each pulse signal of the plurality of pulse signals to be output from the plurality of PWM circuits, based on outputs of the plurality of drivers;
- and
- a latency generator configured to calculate a latency for at least one pulse signal of a plurality of pulse signals and provide the latency in one or more delayable units to the at least one pulse signal of the plurality of pulse signals such that that edge positions of the plurality of pulse signals output from the plurality of PWM circuits do not collide with each other, wherein the plurality of pulse signals change values at the edge positions, wherein the latency generator is configured to generate a table for each of the plurality of pulse signals, wherein each table is configured to indicate positions of changing state of a corresponding pulse signal, and wherein the latency generator is further configured to calculate the latency for the at least one pulse signal based on the data indicating the edge positions of the plurality of pulse signals.
Dependencies are inferred from the claim text.