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LED Driver ICs Forum Discussions

jenss
Level 1
Level 1
5 sign-ins First like received First reply posted

Hello! 

I'm experimenting with BCR601_60V_IVCTRL & REF-XDPL8219 Evaluation Boards. Before hooking some LED stripes to the output I wanted to understand how to set the un-dimmed current and how dimming works.  My test setup is like this (please see photos attached):

  • Electronic resistance connected to BRC601 Board output
  • 100kO poti connected to MFIO / GND Pins 

I was expecting to draw up to 700mAh from the board:

R11, R12 and R13 determine the maximum current of the LED. With the given values of 1.2 Ω, 1.2 Ω and 12 Ω the undimmed LED current is 700 mA typical.

However I could not draw more than 170mA before some protection kicked in and Voltage dropped to zero. Also, changing the resistance (poti) did change oputput voltage and current but in an abrupt manner. 

So I'm wondering what I'm doing wrong here and if such test setup with an electronic resistance is not going to work. 

Thanks,

Jens

 

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Kumarkanahai
Moderator
Moderator
Moderator
10 likes received 5 likes given 25 solutions authored

Hi @jenss ,

Thanks for posting on the Infineon Developer community.

DEMO_BCR601_60V_IVCTRL is a linear LED driver which is meant for the targted load voltage (LED voltage ) of 7 to 54 volts.The over voltage protection will be triggered as soon as the load voltage crosses 54 volt.So,please ensure that the load voltage  is within the limit.

In BCR601 the dimming can be done by MFIO pin in two ways as mentioned below

1.Applying a DC signal at MFIO Pin

The DC dimming will change the output from 3% to 100% when the volatge at the MFIO pin is changing from 0.18 volt to 3.3 volt respectively.When the voltage at the MFIO pin increases more than 3.3 volt,it will operate at 100 % dimming.When the voltage at the MFIO pin is in between 0.18 volt to 0.1 volt ,it will stay at 3% dimming.If the voltage is reduced below 0.1 volt,the LED will be completely switched off.

2. Connecting a series resistance between the MFIO pin and ground.
The dimming can be also done by setting the resistance at MFIO pin in the following way

Kumarkanahai_0-1674571402791.png

As you mentioned that,the requirement is to get the undimmed current .So,it is recommended to apply a DC signal of 3.4 volts at the MFIO pin so that the output will be at 100 % dimming.

Please feel to contact us for further clarifications.

Regards,
Kanahaiya

 

 

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