An integrated circuit and LED constant current drive circuit replacing an external integral capacitor

Abstract

The invention discloses an integrated circuit that replaces an external integral capacitor, which solves the problems in the prior art that an external integral capacitor with a large capacity needs to be connected to ensure that the output current is a constant linear current, resulting in large volume and high cost. The present invention comprises operation amplifier GM, driving circuit, current conversion integrated circuit and capacitor C; Operation amplifier GM charges / discharges capacitor C; Current conversion integrated circuit collects the voltage signal of capacitor C to generate square wave signal, and converts the square wave signal The drive circuit determines the size of the output current according to the voltage, and generates the feedback voltage Vcs as the inverting input signal of the operational amplifier GM; the invention also discloses a new type of LED closed-loop linear constant current control integrated circuit is a A specific application of an integrated circuit that replaces an external integral capacitor. The invention has the advantages of high integration, low cost, long service life and the like.

Description

Technical field [0001] The invention relates to the field of integrated circuits, in particular to an integrated circuit that replaces an external integral capacitor and an LED constant current drive circuit. Background technique [0002] In order to achieve a constant linear current output, various drive circuits in the prior art often set a COMP pin on the integrated circuit, and the integrated circuit connects a UF-level integrating capacitor through the COMP pin to ensure that the output current is a constant linear current. However, due to the large volume of UF-class capacitors and the sharp rise in the price of chip capacitors, the cost of using this traditional method has increased. [0003] Such as figure 1 As shown, the traditional linear LED drive circuit that integrates the output LED current with an external low-frequency large-capacitance capacitor, IS pin uses the voltage on the RCS to compare with the VREF voltage, and integrates the COMP capacitor to obtain the int...

AI Technical Summary

Problems solved by technology

[0006] For integrated circuits in the prior art, because it is necessary to ensure that the output current is a constant linear current, it is necessary to externally connect a UF-level large capacitor through the COMP pin as an integrated circuit with an integral capacitor to ensure that the output current is a constant linear current, because UF grade capacitors are large in size and cannot be integrated on the chip, resulting in a large circuit system collectively and increasing costs. The present invention provides an integrated circuit that replaces an external integral capacitor, which is used to replace the integral function of UF grade large capacitors so as to ensure The output current of the IC is a constant linear current

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