Analog dimming circuit, analog dimming method and LED drive circuit

Abstract

The invention provides an analog dimming circuit, an analog dimming method and an LED drive circuit. The analog dimming circuit is used for generating a dimming signal to control the LED driving circuit to work, and the analog dimming circuit comprises an analog signal processing circuit and a chopper circuit. The input end of the analog signal processing circuit is used for receiving a first analog signal, and the analog signal processing circuit is used for generating a digital signal according to the first analog signal. The first input end of the chopper circuit is coupled with the output end of the analog signal processing circuit, the second input end of the chopper circuit is used for receiving a second analog signal, and the chopper circuit is used for carrying out chopping processing on the second analog signal according to the digital signal so as to output a dimming signal. According to the analog dimming circuit, the analog dimming method and the LED driving circuit provided by the invention, a combined dimming function of dual analog signal input can be realized in an LED driving scheme, the dimming precision of the LED driving circuit is ensured, the circuit structure is relatively simple, and the implementation cost is relatively low.

Description

technical field [0001] The invention belongs to the field of power electronics, relates to an LED dimming technology, in particular to an analog dimming circuit, an analog dimming method and an LED driving circuit. Background technique [0002] In the LED drive circuit, the working state of the system can usually be adjusted through an analog signal or a PWM signal. The existing LED dimming methods include analog signal input dimming, PWM signal input dimming, and analog signal combined with PWM signal combined input dimming. In a specific application scenario, two control signals need to be used to control the same adjustment value. For example, both control signals are analog signals, one of which is used to control the maximum amplitude of the dimming signal, and the other control signal is used to The size of the dimming signal is controlled, and the dimming signal is controlled through the coordinated adjustment of the two control signals, so as to realize the dimming ...

AI Technical Summary

Problems solved by technology

In the scenario where the two control signals are both analog signals, the most direct way is to use the multiplier scheme to realize the modulation of the dual analog signals, but the implementation cost of this scheme is relatively high, and the internal implementation of the chip is relatively difficult, which also leads to control accuracy relatively poor

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