TCA9800: Timing Requirements(Rise time/Fall time) Consult

Stanley Dai

Part Number: TCA9800

Hi Team,

Customer wants to consult with us about the Rise time/ Fall time of TCA9800DGKR. I also attach the D/S screenshot below as your quick reference. The max value of tr and tf is around 270ns/85ns when fscl(max)>100kHz.

Customer's application is: supply voltage for port A / port B = 3.3V, I2C frequency is 62.5KHz. According to I2C standard(also shown below), the tr(rise time) and tf(fall time) can 1000ns/300ns respectively. Does our TCA9800DGKR can support that tr/tf time here? Pls help us check that, thanks.

Best,

Stanley.

over 4 years ago

+1 Clemens Ladisch over 4 years ago

Guru 321920 points

The datasheet is wrong; the last four values in the table are not timing requirements but timing characteristics.

The TCA980x has no limit on the rise/fall time at its inputs.

0 BOBBY over 4 years ago in reply to Clemens Ladisch

TI__Guru* 79221 points

Clemen's assessment of table 7.6 which you showed in your original post is correct. 7.6 should be labeled characteristics since it describes the behavior of our device's rise/fall time at the set loading conditions. Again, these are not requirements.

-Bobby

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TCA9800: Timing Requirements(Rise time/Fall time) Consult