• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 13 subscribers
  • Views 179 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

ISO1228DFBEVM: RPAR with different value compared to data sheet ISO1228 and ISO228EVM

MAURICIO VIDAL
Intellectual 260 points
Part Number: ISO1228DFBEVM
Other Parts Discussed in Thread: ISO1228, ISO1228EVM

Tool/software:

Hi everyone:

For the ISO1228DFBEVM, on its data sheet on the Table 1-1. it considers 16K for the RPAR. 

However, on the Table 8-1. of the ISO1228 data sheet and also on the Table 1-1. of the ISO228EVM in both cases a 13K is considered for RPAR, being in all the 3 cases the same selection for Sink Mode and IL = 2.5mA.

What would be the reason for the difference? At first I thought maybe it was related to the LED selection, but both evaluation modules use the same 150060VS75000 LEDs.

  • +1
    TI__Mastermind 29185 points

    Hello Mauricio, 

    ISO1228DFBEVM was released with RPAR = 16kΩ. Since making RPAR = 13kΩ slightly improves the input current regulation, ISO1228EVM was released with RPAR = 13kΩ. Therefore, ISO1228 datasheet also suggests using RPAR = 13kΩ

    Please use the 13k-ohm value in your design for the best performance. Both values would work, however, the 13k-ohm value would match the datasheet performance shown in 5.11 Typical Characteristics. 

    Best,
    Andrew