Design Of Low Power Touch Dimming Circuit

The development of science and technology has promoted the improvement of people's living standards,which has made people's demands for quality of life higher and higher.The traditional two-state light adjustment and control method cannot achieve precise control of the lighting brightness,but also cause waste of energy.Therefore,the touch adjustment of light brightness has become a hot spot for scientific research.For the need of dimming,in this thesis,we propose a low-power touch dimming circuit design based on human visual characteristics.Compared with the traditional dimming circuit,the design realizes touch dimming in which the brightness of the human eye changes uniformly,and the power consumption is lower than other dimming circuits.In this thesis,firstly,we propose a high-speed,low-power touch detection circuit.By using a clocked comparator structure,the power consumption of the touch detection circuit is reduced.At the same time,the output speed is improved by the improved discharge branch structure.Secondly,we propose the gated clock structure based on touch frequency self-adaptation,and realize the switching between sleep and working modes through the gated clock structure.At the same time,the adaptive controller of the counting control module can intelligently reduce the power consumption of the circuit by adjusting the waiting time of the operating mode adaptively according to the touch frequency.Then,we propose a dimming circuit based on the human visual characteristics,which using the inverting “S” dimming function instead of the linear dimming function to calculate the duty cycle of the pulse signal,in order to eliminate indirect flicker caused by human visual characteristics.Finally,in order to ensure the operation of the digital circuit,a voltage-stabilized frequency-locked loop structure is used as the clock drive of the circuit,and the feedback regulation of the closed-loop improves the anti-interference ability of the clock module and reduces the clock jitter.According to the study of each module,we give the specific circuit design,layout design and the corresponding simulation results.In this thesis,the design for dimming has been fabricated in GSMC 0.18 um process,and we test the function and performance of the circuit.The test results show that the circuit can switch between the working mode and the sleep mode,and,it can complete the adaptive adjustment of the waiting time.The frequency of the output is 1.934 kHz,and the dimming brightness level is 255.Compared with the inverting “S” dimming function,the duty cycle distortion is less than 0.683%,and the circuit transmission delay is approximately 73.89 ms.Power consumption is less than 14.803 mW.Therefore,the dimming circuit designed in this thesis has good application prospects.