一种LED驱动芯片开路检测电路设计与实现

Design and Implementation of an Open Detection Circuit for LED Driver Chip

小间距发光二极管(LED)显示屏凭借其画面清晰细腻、色彩自然真实、流畅无闪烁等优点,得到广泛应用。为解决小间距LED显示屏因寄生电容影响而产生的开路十字架问题,采用在模拟电路部分判断开路状态并产生开路信号,在数字部分根据开路信号记录开路位置并屏蔽输出的方式,设计了一种新的检测过程简单、精确度高、面积小、功耗低、支持实时检测的电路,并在某款多路恒流LED驱动芯片中得到应用,成功解决了开路十字架问题。仿真结果和实际样片测试结果表明,所设计的开路检测电路检测精确简单、功耗低,并支持实时检测。

The fine-pitch light emitting diode(LED) display screen is widely used for the advantages of sharp image, natural color and smoothness without flicker and so on. A new kind of circuit was designed to solve the open cross problem caused by the parasitic capacitance of the fine-pitch LED display screen. In the analog circuit part, the open circuit state was judged and an open circuit signal was generated. In the digital part, the open circuit position was recorded according to the open circuit signal and the output was shielded. The circuit detection method is simple, highly accurate and real time. And the chip has small area and low power consumption. It has been applied in a multi-channel constant current LED driver chip to successfully solve the open cross problem. The simulation and actual sample chip test results show that the designed open detection circuit is accurate and simple to detect with low power consumption and supports real-time detection.