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LP8725 I2C address clarification

Stephen Swearingen
Prodigy 50 points
Other Parts Discussed in Thread: LP8725

Hello all,

Table 1 shows the I2C address of this device based on CONFIG and DEFSEL pins. The four possible 7-bit addresses are:

   0x78;  1111000_

   0x79;  1111001_

   0x7A;  1111010_

   0x7B;  1111011_

      Note: "_" is supposed to represent the R/W bit

These I2C addresses seem to be reserved according to the I2C specification, yet there are Linux drivers so I assume things are working fine. I can not find an evaluation board to buy and verify for myself.

Seems that I2C addresses 11110xx_ are supposed to be ignored by 7-bit I2C slaves; used for 10-bit addressing.

Additionally I2C addresses 11111xx_ are supposed to be reserved for future use.

 

Can someone clarify the I2C addressing?

Is the LP8725 not compliant with I2C Specification wrt slave addressing?

 

Regards,

Steve

 

 

  • 0
    TI__Prodigy 250 points
    Hi Steve,
    You are correct, LP8725 is not fully compliant with I2C specification. I2C addressing does conflict with 10-bit addressing. If you don't have any 10-bit slaves on the same I2C bus this is not a problem. Also I2C master must support RW operations to this slave address.

    br.
    Anssi Räisänen