Actions
Forum Thread Details
  • State Not Answered
  • Replies 2 replies
  • Subscribers 77 subscribers
  • Views 115 views
  • Users 0 members are here
Related

Red LED occasionally not working on 1312020030000 chip LED

DarienRodrigues

We have the WL-ICLED 1312020030000 chip LED powered from a 3V source. The red, green and blue LEDs independently work most of the time. But occasionally, the red LED stops working, while the blue and green continue to work. We are controlling the DIN signal from a MCU, which is also powered from the 3V DC source. I understand that the rated VDD supply is 3.3-5.5V. It does not make sense that only the red LED should stop working when the voltage is below the rated minimum. Additionally, this failure is only occasionally observed. Has anyone else faced this issue. If yes, how was this resolved?  Should the DOUT pin be pulled low or connected to GND, if not used? We are using a 4 MHz clock frequency for the DIN signal.

  • 0

    Have you checked the datasheet, to see what the max data rate is supposed to be? Was 4 MHz chosen regardless?

    Unless it's a non-critical product (such as a toy or game) where there's no issue with a faulty indication, I think it's best to use the product within the specification, which means 3.3V minimum, not 3V.

  • 0

    As Shabaz has reminded you - 3.0V is out of spec for this device - there is no reason to expect it to work correctly. It will of course obey the usual laws of physics, but unless, you have detailed information about its insides, you can't predict how these will manifest themselves - it may make prefect sense that the red LED fails to illuminate when the chip temperature is just at a certain point.

    I don't understand which clock you are referring to  - DIN on the diagram on the data sheet is a combined clock and data signal and the bit period should be between 0.9 and 1.5us  - which is equivalent to 1.1MHz > fDIN > 0.667Mhz. 

    Check your waveforms on a scope (and post them here if you are still stuck).

    MK