A led dimming chip

Abstract

The invention discloses an LED dimming chip. The dimming chip includes a current detection module, a judging module, a switching module, a driving module, a power supply module and at least one power tube. The invention detects whether the source of the power tube has current flowing through the on-off detection switch, thereby avoiding the influence of capacitance in the circuit on the detection accuracy of the switch. The problem of inconsistency in discharge time caused by differences in external application devices and misjudgment of switch on-off is avoided. The internal clock timer of the chip controls the preset time, and the dimming consistency is high, which avoids the misjudgment of the detection by the switch interference, and ensures that the switch dimming method can be used in a large area.

Description

technical field [0001] The invention relates to the technical field of LED lighting control, in particular to an LED dimming chip. Background technique [0002] At present, there are many forms of LED dimming circuits on the market, mainly divided into thyristor dimming, PWM dimming and switch dimming, etc. Most of the switch dimming judges the on of the power switch by detecting the level of VCC voltage. -off action, its working principle is: the chip VCC will be maintained at a fixed voltage during operation, when the switch is turned off, the chip VCC will start to drop until it drops to a certain set value, triggering the detection action of the chip, thus there is The following two problems: On the one hand, the falling time of VCC is greatly affected by capacitor parameters, such as the actual capacity of the capacitor, the leakage current of the capacitor, and the temperature characteristics of the capacitor. These parameters of capacitors from different manufacturers...

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Problems solved by technology

[0002] At present, there are many forms of LED dimming circuits on the market, mainly divided into thyristor dimming, PWM dimming and switch dimming, etc. Most of the switch dimming judges the on of the power switch by detecting the level of VCC voltage. -off action, its working principle is: the chip VCC will be maintained at a fixed voltage during operation, when the switch is turned off, the chip VCC will start to drop until it drops to a certain set value, triggering the detection action of the chip, thus there is The following two problems: On the one hand, the falling time of VCC is greatly affected by capacitor parameters, such as the actual capacity of the capacitor, the leakage current of the capacitor, and the temperature characteristics of the capacitor. These parameters of capacitors from different manufacturers cannot be unified, even if they are the same Capacitors of different manufacturers, these parameters also have deviations, which seriously affect the accuracy of switch detection; When the switch controls multiple lights, the power supply is switched on and off quickly, and the dimming status between the lights is inconsistent, which makes the switch dimming unable to be used in commercial large-area areas such as shopping malls and supermarkets.

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