Constant current control chip, system and led constant current drive circuit

Abstract

The present invention provides a constant current control chip, system and LED constant current driving circuit, and relates to the technical field of integrated circuit chips. The constant current control chip includes: a starting and dimming circuit module, a reference power supply module, a driving module and a constant current Control module; set the threshold through the two internal undervoltage protections. When the voltage of the energy storage capacitor C2 drops during the operation of the constant current control system, causing the voltage of the power supply voltage terminal VCC of the constant current control chip to drop to the shutdown voltage, it will be turned off in time. The chip; the chip is turned on when the voltage of the energy storage capacitor C2 rises to the chip's internal turn-on voltage, which avoids the problem that the working point of the chip's internal circuit is shifted due to the low voltage of the power supply voltage terminal VCC, and the internal logic is disordered, causing damage to the entire system. . Moreover, the circuit structure of the constant current control chip is simple, and the functions of overvoltage protection, undervoltage protection and dimming are realized through a small number of components, and the cost of the LED constant current dimming system is reduced.

Description

technical field [0001] The invention relates to the technical field of integrated circuit chips, in particular to a constant current control chip, a system and an LED constant current drive circuit. Background technique [0002] LED (full name: Light Emitting Diode) is a solid-state semiconductor device that can convert electrical energy into visible light. It has the advantages of high luminous efficiency and long life. LEDs have diode characteristics and need to be driven by a constant current source to control the LEDs. [0003] LED lighting applications on the market usually use constant-current control chips to design constant-current control systems. Common constant-current control chips are divided into a common-ground structure for taking power at the input end and a floating structure for taking power at the output end. Compared with the common ground structure, the floating ground structure has many advantages. Its structure is simple, the system design is more co...

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Problems solved by technology

[0004] Therefore, the problem is that when the chip is started, the voltage of the power supply capacitor drops. If the voltage of the power supply capacitor drops to affect the internal working point of the chip circuit, the back-end output voltage still cannot charge the power supply capacitor, and the chip will face logic problems. Disorder, in severe cases, the chip will be damaged

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