I am using two devices in my application.
1. TLC59116 with 3.3V power supply and LED power supply of 5V (3 mm LEDs).
2. TLC59108 with same power supply and LED power supply of 5V (5 mm Red LEDs). The forward voltage mab different compared to 3 mm LEDs.
While running with default mode of IREF setting and Rext of 710 Ohm, Both devices works, I able to control the current using PWM value. There is output current problem in TLC59108 where as TLC59116 work perfectly as per calculation.
My target value is 3 mA for each LEDs. When I program the same in IREF (0x17) with Rext of 710 Ohm. The device TLC59116 works fine (3 mm LEDs) whereas device with LEDs (5 mm) TLC59108, I do not able see the light in LEDs even the PWM value is 0xFF. I am using IREF register address of 0x12 in TLC59108 as per datasheet.
While reading data and blogs, I found that Figure 13 define the Iout versus Vout Value will play role for my problem. It does not give any formula to know for 3 mA, what is minimum Vout so that Current can flow in LEDs. Does it really reason or some thing else. What is safe value of Vout at output pin so that we will not problem. It is possible to change power to LEDs (12V instead of 5V).
Let me know, reason of problem and its solution.
Thanks in Advance.