Hello,
I'm working in Traffic Signal Technology Factory. We have several types of LED count down displays. Recently we are facing some problem with our count down display. We have count down displays for showing red time and green time. But before one month we are facing a severe problem with this count down. During red time, some green segments are glowing. That means, there is some leakage current in the output of green count down section. Now red led section is also having the same problem. Earlier we used the MBI5026 but 2 weeks before i got samples from texas instruments and i replaced the macroblock MBI 5026 with texas instruments' TLC5926. 48hours it worked fairly good, but now the same problem is facing with texas ic also. But as compared to MBI5026, the leakage current of TLC5926 is less. How can i eliminate the leakage current in this 16-channel current sink LED Driver IC???
Manesh,
The leakage spec on the TLC5926 is <1uA at 125C. What do you believe you are seeing on your system? Leakage would be a function of the LED voltage and the temperature. If there is leakage coming from other paths, that may be another issue (solder process, PCB and other manufacturing concerns).
What is the nominal current set to on your system now (REXT value)?
What is the LED Voltage? What are your nominal LED forward voltages?
What is the data communication speed? Is there a chance that the system is inadvertently writing bits to the wrong state?
Regards,
dick