MBR3, Pull down on I2C line

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Anonymous
Not applicable

Hello,

I would like to check the reason why MBR3 require pulled-up on I2C line if the pins is unsed.

Basically, I2C should be used by pulled-up but if I2C is not used and does not connect to anything device, MBR3 is not controlled ever after even if MBR3 enter stard condition. So I think we can be pulled-down on I2C line.

Please let me know the reason MBR3 need pulled-up.

Best regards,

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1 Solution
Vison_Zhang
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First comment on KBA 750 replies posted 250 sign-ins

The default drive mode of I2C pins is open drain - drive low, if I2C is not used the state of SCL/SDA is High-Z (with big input impedance) which is easy to couple noise from the outside to inside,

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4 Replies
Vison_Zhang
Moderator
Moderator
Moderator
First comment on KBA 750 replies posted 250 sign-ins

The default drive mode of I2C pins is open drain - drive low, if I2C is not used the state of SCL/SDA is High-Z (with big input impedance) which is easy to couple noise from the outside to inside,

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Anonymous
Not applicable

Hello xzng-san,

Thanks. That right.

If the reason is only external noise, I would like to put pull-down to the I2C pins at the view point power consumption.

Is it OK?

Best regards,

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Pull down is good,  just don't leave SDA/SCL pin float is fine.

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Anonymous
Not applicable

Hello

Thank you very much.

Best regards,

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