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LP8866-Q1: Question about power on reset in fault situation

Chase Jeong
Mastermind 7485 points
Part Number: LP8866-Q1

Tool/software:

Dear TI experts,

My customer asked about power on reset in fault situation. Could you check these questions?

1. In the table 6.9 of the datasheet there are lists of fault situation.

There are auto recovery faults and also faults which need to be reset manually.

Is it okay to do power on reset in all fault situations although some faults are auto-recoverable?

(Because my customer do not use I2C so they do not know what fault occur exactly, so they want to always do power on reset.)

2. Is it okay to control PWM signal by main MCU, and I2C communication is connected to sub MCU which is in monitor module?

In that case, They need to communicate via I2C (sub MCU in the monitor) while PWM is controlled by MCU which is outside the monitor.

Please check these 2 issues. Thanks.

Best regards,

Chase

  • 0
    TI__Mastermind 27296 points

    Hi Chase

    Our expert  will reply to you soon.

    Thanks and best regards.

  • +1
    TI__Mastermind 31405 points

    Hi, Chase

    For case1, it is related with the customer system level requirement, if they can accept, device level has no concern here.

    For case2, sure, it will work, as it has the I2C control, can it control the brightness with I2C directly? We have a PWM IN register to shown what we detected from PWM pin.

  • 0 in reply to Zhiqian Wu
    Mastermind 7485 points

    Dear Zhiqian,

    Thank you for your support.

    Could you check 2 more questions from my customer?

    1. Power on reset which I mentioned is just disconnect VDD and re-connect it. right?

    Does it have same effect that I control EN pin low and back to high?

    My customer wants to reset all the register values after reset.

    2. What is the speed of I2C communication of LP8866-Q1? I cannot find the settings about I2C communication speed.

    (Master's speed only supports 100Kbps and 400Kbps.)

    Best regards,

    Chase

  • 0 in reply to Chase Jeong
    TI__Mastermind 31405 points

    Hi, Chase

    Q1: Yes, EN pulled down and up can also reset the system, btw, we recommend to ensure that VDD is higher than EN pin.

    Q2: It is mentioned in the EC for maximum 400kHz.