cancel
Showing results for 
Search instead for 
Did you mean: 

Knowledge Base Articles

What is the recommended capacitive OUT filtering for LITIX Basic products?

MohammedA_41
Employee

What is the recommended capacitive OUT filtering for LITIX Basic products?

For all LITIX Basic variants with "Open Load" detection functions the following recommendation applies: 

  • LITIX Basic ICs with integrated Open Load functions require a capacitive divider on the OUT. This means CVS2OUT and COUT2GND should be implemented to achieve a robust EMC design. This has been evaluated during our EMC investigations. The reason for this is to increase filter capacitance on the OUT. If it is only done via increasing the COUT2GND capacitor, the open load detection is not working properly anymore. To avoid this the CVS2GND has been recommended as well. 

For all LITIX BASIC ICs without the "Open Load" detection function implemented the following recommendation applies: 

  • LITIX Basic products without Open Load detection functions such as TLD1120 do can skip the CVS2OUT capacitor.
  • The GND connection of the LED load can cause a parasitic behavior during the BCI test. The layout of the PCB Board design is also an important factor how many disturbances the IC OUT or in this case the current regulation loop of the IC will see during the BCI test. The COUT2GND will filter eventual disturbances and ensure a more stable output current regulation. 

NOTE: The actual datasheet drawing of the TLD1120 is showing a CVS2OUT capacitor only! This may not solve BCI issues and a COUT2GND filter is recommended. A dedicated AppNote is planned to focus on this topic.

0 Likes
Version history
Revision #:
1 of 1
Last update:
‎Nov 25, 2021 04:48 AM
Updated by:
 
Contributors