• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 46 subscribers
  • Views 953 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

REF1925: the need of diode

Takao Yamamoto
Genius 4135 points
Other Parts Discussed in Thread: TINA-TI, REF1925

Dear all,

I simulated this device at TINA-TI.

Could you teach me about attachment file within a few days?

QUESTION_REF1925.xlsx

■QUESTION (the same as attachment file)

1. Could you teach me the reason of the need of external diode?

2. Could you teach me the characteristics of diode to be needed?

Best regards,

  • 0
    TI__Genius 9975 points

    Hello Takao Yamamoto-san,

    I do not know the purpose of the diode shown in your attachment. The REF1925 model available from ti.com does not have such diode.

    My only guess is that the diode could be used for draining C2 to ground via R1 but in a typical application the diode would not be included.

    I hope this helps.

    Best regards,

    Jose

  • 0 in reply to Jose Duenas
    Genius 4135 points
    Dear Jose,

    Thank you for your answer!
    However, I would like to check one thing.

    We use this diode to protect this device from temporary blackout.

    We think that the charged voltage in C2 will damage this device with temporary blackout.
    Is this wrong?

    Do we need to use this diode?

    Best regards,
  • 0 in reply to Takao Yamamoto
    TI__Expert 5485 points

    Hello Takao Yamamoto San

    Using diode to protect REF1925 during input balcout could be one of the reasons to use this diode.

    Adding this diode will discharge the C2 through 2.8Ohm resistor and avoid any possible reverse current through REF1925 in blackout conditions.

    If you have sufficient load on output to dischrage C2 quickly then you probably will not need this diode.

    Thanks & Regards

    Abhijeet Godbole