I am using RTC with I2c specs at 100Khz. Now specs says that min Tlow = 4.7us & min Thigh = 4us.

Now freq = 1/ (Tlow + Thigh) = 1/(4.7 + 4) = 115Khz while this specs is for max 100Khz clk.

What is this error

 

What error?

Best to state the RTC part number.

 

No rtc error, but specific to I2c spec error.

Like I2c specs define Max scl freq = 100Khz.
while with tlow & Thigh, its comes out to be 114khz max.

 

Ok then, make min Tlow = 5us and min Thigh = 5 us.
Does that make you happier?

 

I am using RTC with I2c specs at 100Khz. Now specs says that min Tlow = 4.7us & min Thigh = 4us.

Now freq = 1/ (Tlow + Thigh) = 1/(4.7 + 4) = 115Khz while this specs is for max 100Khz clk.

What is this error

No error, just interpretation.

Obviously if you have a minimum Tlow you can't also run Thigh at it's minimum and also meet the frequency rate.

There's also a transition time between low and high not included in your frequency calculation.

 

thanks ErnieM.<br />
<br />
Are you talking about tr &amp; tf. If yes they should be minimum &amp; in datasheet there min value is not defined &amp; there max value is defined roulette