LED open circuit detection circuit and method, LED driving chip and driving method

Abstract

The invention relates to an LED open circuit detection circuit and method, an LED driving chip and a driving method. The circuit comprises an excitation module used for applying excitation voltage between an anode and a cathode of a currently detected LED, wherein when the currently detected LED is in an open circuit, the excitation voltage is greater than the conduction voltage drop of the currently detected LED and is less than a voltage threshold, and the voltage threshold is the conduction voltage drop of two LEDs connected in series, when the currently detected LED is normal, the excitation voltage is equal to the conduction voltage drop of the currently detected LED; and a judgment module which is used for collecting the excitation voltage, comparing the excitation voltage with reference electrical parameters and judging whether the currently detected LED is in an open circuit state or not according to a comparison result. According to the invention, by detecting the open-circuitLED, the open-circuit LED can be not lighted during driving, so that the problem that other LEDs are mistakenly lighted due to the open circuit of the LED can be avoided. And the excitation voltage during detection is greater than the conduction voltage drop of the LED and less than the voltage threshold, so that the excitation voltage can be prevented from mistakenly lightening other LEDs when the LED is in an open circuit state in the open circuit detection process.

Description

technical field [0001] The invention relates to a detection device for electrical faults, in particular to an LED open circuit detection circuit, and also relates to an LED open circuit detection method, an LED drive chip, and an LED drive method. Background technique [0002] At present, most LED (light-emitting diode) light bars on the market are equipped with dynamic scanning driver chips. With the development of science and technology, there are more and more dot matrices in the LED panel, and the number of drive ports of the drive chip also increases accordingly. The increase in the number of ports means an increase in the chip area, higher production costs, and even larger chip packaging volume, which is not conducive to board-level applications. [0003] Therefore, the LED multiplexing drive mode came into being, and its drive port combines the drive functions of the SEG (segment selection) port and the GRID (bit selection) port, such as figure 1 As shown, only a se...

AI Technical Summary

Problems solved by technology

[0005] Based on this, it is necessary to provide an LED open-circuit detection circuit and method, an LED driver chip and a driving method, and perform open-circuit detection on the LED dot matrix in the multiplexing driving mode, so as to avoid the problem of abnormal display effect of the chip in practical applications.

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