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AFE4403: LED current temperature dependency

Shota Mago
Expert 8160 points
Part Number: AFE4403

Hi team,

I'm an FAE supporting some industrial customers in Japan.

My customer will employ AFE4403 for their product and provided some questions as follows.

Questions

  1. Does LED setting current have temperature dependency?
    (Does AFE4403 have characteristics that accuracy of setting current deteriorates  or doesn't flow  at all via temperature?)
  2. Does AFE4403 do feedback control internally for current setting?
    1. If so, could you please provide more detail?
      e.g. feedback value 
    2. If AFE4403 has condition for correct control, could you provide that?
      e.g. w/o photo-diode, AFE4403 can't control LED

I'm looking forward to hearing back from you.

Best regards,

Shota Mago

  • 0
    TI__Genius 12575 points
    Hi Shota,

    In a system level, the drift in the LED current due to temperature will be insignificant as the drift in the intensity of the LED will be huge across temperature. So, drift of LED's intensity should be of more concern.
    We don't have any feedback control settings for LED current.

    For 2b, I am assuming that customer wanted to know if there is any internal mode that sets the LED current to 0 in absence of photodiode. If yes, then there is no such control that automatically does that. However we have internal diagnostics mode, whose output can be read by the external MCU and updon detection of errors ( such as absence of photodiode), the LED current can be programmed by the MCU to be 0.

    Regards,
    Prabin.