Switch dimming led dimming circuit and led dimming circuit chip

Abstract

The invention provides an LED dimming circuit with a switch capable of dimming. The LED dimming circuit comprises a power supply isolator, a signal generator, a cycle counter, and a digital-to-analog converter (DAC), wherein the power supply isolator is used for generating voltage VDIM and providing power for the signal generator and the cycle counter; the signal generator is used for generating clock signals CLK for controlling the cycle counter; the control end of the cycle counter is connected with the clock signals CLK outputted by the signal generator; when the CLK is high in level, the cycle counter counts; the output end of the cycle counter is connected with each digital input end of the digital-to-analog converter DAC; the digital-to-analog converter DAC outputs corresponding reference voltage Vref according to the coded signals outputted by the cycle counter. An LED dimming circuit chip further comprises a power supply part used for providing internal supply voltage VDD for the chip, the voltage reference maximum Vref_max, and generating enable signals EN along with the change of the switch of the LED lamp. According to the LED dimming circuit disclosed by the invention, the switch on the wall is used for generating the clock signals, and the clock signals control the cycle counter to count, so as to continuously adjust the reference voltage Vref and realize non-polar continuous dimming.

Description

technical field [0001] The invention relates to the field of LED lighting, in particular to an LED dimming control circuit. Background technique [0002] Traditional LED dimming technologies mainly include thyristor dimming, PWM dimming, etc. However, these two dimming technologies require the design of corresponding circuits inside the chip, and the addition of some other chips or devices to the solution to achieve dimming. function, which will inevitably lead to an increase in the volume of the entire solution, and a corresponding increase in cost. [0003] The segmental dimming that appeared later, selects different current references by controlling the switching times of the wall switch, and the current reference directly controls the output current, thereby realizing the dimming function of the LED. This dimming technology is controlled by a wall switch, without the need to rewire and modify the switching system, which is simple to use and has a good cost advantage. H...

AI Technical Summary

Problems solved by technology

However, this dimming method can only realize LED dimming of several brightness levels, and cannot realize the stepless continuous dimming function of LEDs.

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