Multi-channel synchronous dimming circuit

Abstract

The invention relates to the technical field of load driving, and discloses a multi-channel synchronous dimming circuit, which comprises a voltage control module, a plurality of load branches, a current regulation module, a dimming signal output module and a dimming signal coupling module, and is characterized in that each load branch comprises a load and a switching tube which are electrically connected in series; the dimming signal output module is used for inputting PWM signals for independently dimming corresponding loads to each load branch, and the dimming signal coupling module is used for coupling a plurality of PWM signals into a control signal for carrying out total dimming and outputting the control signal, so that under the condition that the output power is not changed, the PWM signals can be subjected to total dimming; the aim of dimming in a single channel and any multiple channels without mutual influence is achieved, the cost of adding an additional channel is only limited to the cost of adding one switching tube, no inductor is applied in a post-stage circuit, the strong EMC problem is not generated, and the circuit is simple in structure and low in cost. Therefore, in practical application, the size and cost control of the driving power supply has obvious advantages.

Description

technical field [0001] The invention belongs to the technical field of load driving, and in particular, relates to a multi-channel synchronous dimming circuit. Background technique [0002] As the LED (Light-Emitting Diode, light-emitting diode) dimming power supply market puts forward higher standards for dimming depth, multi-channel, output flicker-free and product cost, etc., the existing technologies / solutions are becoming more and more The more difficult it is to meet these requirements, especially for solutions with high requirements for multiple indicators, it is more difficult to achieve a suitable balance. Either the cost is too high, or the performance cannot meet the requirements. For example, for multi-channel dimming / RGB dimming applications This contradiction is more prominent. In detail, the market trend is not only requiring no stroboscopic, lower THD (Total Harmonic Distortion, total harmonic distortion), higher light efficiency and lower dimming brightness...

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