TLC6C5716-Q1: R-iref test

Hi Ryan,

How did you measure this output current?

RIREF sets the full-scale current. However, if BC, DC is not set the max, and the GS is not 100% brightness, the output current is not full-scale.

BR, Gracie

Gracie,

1、R-iref=1.5K

2、Other parameters are：

BC ：255  DC：60  GS： 4095（12bit GS mode）

3、LOW RANGE mode，

Calculation based on below formula from datasheet：

Measured current is 3.241mA ->  Iout（MAX） is 10mA which doesn't match below curve in datasheet.

Hi Ryan,

I agree with your calculation at this point. The calculated full-scale current is 32mA while the actual is 10.2mA. It's barely impossible. Could you pls verify all of the conditions you listed above?

BR,Gracie 

Gracie,

To verify the problem, customer test with HIGH RANGE mode this time：

1、R-iref=1.5K ，Vcc 3.3V ， V-sense 5V

2、BC ：255  DC：60  GS： 4095（12bit GS mode）

3、HIGH RANGE

Datasheet calculation is ：

Current measured is  6.655mA -> Iout（MAX） 10.265mA which still doesn't match curve in datasheet.

Could you comment what might be wrong in customer side?

Thanks 

Hi Ryan,

I am wondering how the current is measured. Did customer measure the total current from the power supply? I doubt if the corresponding DC is set correctly. Also, what's the Vf of LED in this case? I doubt if VLED is not sufficient for the Vheadroom of LED driver.

BR, Gracie