MPL3115A2 I2C VOL value

[stephenthomas]

Hi ,

I have seen the VOL value specified in datasheet for MPL3115A2 for SDA lines as VOLS = 0.1VDDIO  specified for Io=500uA i.e 0.33V @ Io=500uA

as Im using VDDIO 3.3V. I have pull up resistors of 10kOhm connected.

I want to analyse the variation in VOL value i.e my actual sink current 3.3/10k=0.33mA .

Is it possible to obtain the VOL values at this current. Or can it take it like Rds on of MOSFET =0.33/500uA=660Ohm

as use it to calculate the VOL @ 0.33mA as 0.33mA x 660Ohm =0.2178V Will it be correct?

[david_diaz]

Hello Stephen,

I understand your analysis and you might be right about the VOL value, BUT, please be aware that VOL value cannot be characterized because the internal MOSFET has no a linear behavior.

For example, at the MOSFET saturation, regardless of the voltage across (with limits of course) the current through the device will be (almost) constant.

Besides, please be aware that the Io is just a test condition value.

I hope this information will be useful for you.

If I misunderstood your question, feel free to let me know.  I will be glad to help.

Have a great day.

David Diaz.

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