led drive circuit and led drive chip

Abstract

Provided is an LED driving circuit, comprising a rectifying circuit (100), an LED power supply circuit (300) and an LED driving chip (200), wherein the LED driving chip (200) can generate a current reference with a frequency at least twice the frequency of the alternating current output by the rectifying circuit curve, and control the LED power supply circuit (300) to provide the LED lamp with a current consistent with the frequency of the current reference curve. Also provided is an LED driving chip (200), capable of generating a current reference curve whose frequency is at least twice the frequency of the input alternating current, and controlling peripheral circuits to provide LED lights with current consistent with the frequency of the current reference curve. The LED driving circuit and the LED driving chip of the solution can suppress the low-frequency output current ripple, solve the low-frequency flickering problem in the process of supplying power to the LED, and have simple design, low production cost and high working reliability.

Description

technical field [0001] The invention relates to the technical field of LEDs, and more specifically, to an LED driving circuit and an LED driving chip. Background technique [0002] Current AC-to-DC (AC / DC) LED drive circuits are divided into single-stage and two-stage. The output current of the two-stage circuit has no low-frequency ripple, but the cost is relatively high. Low-cost single-stage AC-to-DC LED driver circuits have low-frequency ripple at AC frequencies after the larger output is rectified. For example, the AC frequency input to the AC-to-DC LED drive circuit is 100Hz. If there is AC power with a frequency below 120Hz in the AC power supplied to the LED, the LED light will flicker (flickernoise). This low-frequency flicker can be clearly seen with mobile phones, video cameras and other devices. If the DC output is used, the power frequency ripple can be reduced and a stable output can be provided to the LED lamp, but the circuit must be connected in parallel ...

AI Technical Summary

Problems solved by technology

If you use DC output, you can reduce the power frequency ripple and provide a stable output to the LED light, but the circuit must be connected in parallel with a large-capacity electrolytic capacitor for filtering

[0003] However, the method of using DC output to power LED lamps has the following problems: First, the LED power supply is generally integrated with the LED lamp, and its working environment temperature is very high

However, this method uses separate devices and is not highly integrated

Secondly, this method is more complicated, and its components are more expensive

Unable to achieve the purpose of universal application

[0007] In summary, the prior art has the defects of complicated design, high production cost, poor working reliability and short service life

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