• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 49 subscribers
  • Views 534 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.

BUF08821 - programmed output voltage setting when Vs turned ON->OFF->ON

Kawai
Guru 19775 points
Other Parts Discussed in Thread: BUF08821, BUF08821EVM-USB

Hi Team,

Could you please tell me about the gamma buffer BUF08821 ?

Our customer will use this device in the following sequence.

1) Power up Vsd (power for digital circuit)

2) Power up Vs (power for analog circuit)

3) program output voltage through I2C

After programmin the registers, they have the situation that Vs would turn OFF -> ON.

[Question]
In the above case, does BUF08821 output voltage resets to the default output voltage setting (Vs/2), or does the device keep the programmed value as Vsd is kept supplied ?

Best Regards,
Kawai

  • 0
    TI__Genius 14825 points

    Kawai,

    I looked through some discussions about the BUF08821 and found this response from a colleague that may shed some light on the subject.  I'm not sure if it answers your question completely but I wanted to pass it along anyway.

    "With the assistance of the design team I have confirmed that both analog and digital supplies are required to latch the OTP.  At AVDD = 6V and DVDD = 2V the POR reset will occur and begin reading the OTP...it will take approximately 850uS to read the OTP following the POR and during this time the output will be at AVDD/2. Also, the analog supply does have to be present to write to the device.  Once the Analog supply reaches 7V communications can be initiated immediately."

    Does the customer have our BUF08821EVM-USB?  It could be useful for debug and testing of this situation.

    Let me know if the customer needs more information of if this is satisfactory.

    Thank you,

    Jason Bridgmon

  • 0 in reply to Jason Bridgmon
    Guru 19775 points

    Hi Jason-san,

    Thank you for giving us this information.

    I have input this info to our customer. I would appreciate for your continuous help when there are further questions.

    Best Regards,
    Kawai