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ADM3260 side1 and side2 logic levels definition

Question asked by adi_susan Employee on Mar 15, 2017
Latest reply on Mar 15, 2017 by jnaso

Hello,

After reading the datsheet of ADM3260 and ADuM1250, I'm a little bit confused.

For the side1 of ADuM1250, it's compatible with I2C threshold, side2 is standard I2C logic levels and this is also the I2C bus side.

For ADM3260, side1 and side2 are same as ADuM1250? But, from Figure 27 of the datasheet, side 2 is connected to controller and side1 connected to other I2C devices(that is I2C bus).

one issue here: side1 has modified logic level , the output low voltage is around 0.8V, if another I2C device have 0.3VDD logic low threshold and VDD=3, that means logic low threshold is 0.9V. 0.8V and 0.9V just have 100mV difference, if the system have some noise or the cable between side1 of ADM3260 and other I2C device is long, some logic error will easily happen.

From my opinion, side1 and side2 seems not reasonable for ADM3260. Please correct me if I made mistake.

 

Regards,

Susan

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