PCA9548A: I2C Signal Rise Time Test Condition Consult

Stanley Dai

Part Number: PCA9548A

Hi Team,

Customer wants to know what's the detailed test condition for I2C input rise time? I cannot find it in our D/S, pls help us look at this. Thanks.

Best,

Stanley

over 3 years ago

0 Clemens Ladisch over 3 years ago

Guru 317260 points

These values are simply copied from the I²C specification. There are no fixed test conditions; these timings must be met by the actual circuit.

The specification also says this about the fall time:

[6] The maximum t_f for the SDA and SCL bus lines is specified at 300 ns. The maximum fall time for the SDA output stage t_f is specified at 250 ns. This allows series protection resistors to be connected in between the SDA and the SCL pins and the SDA/SCL bus lines without exceeding the maximum specified t_f.

0 Stanley Dai over 3 years ago in reply to Clemens Ladisch

TI__Expert 5810 points

Hi Clemens,

Thanks for comments. Do you know what's typical voltage range we will take for estimating this rise/fall time? Like 20%-80% of voltage?

Best,

Stanley

0 Clemens Ladisch over 3 years ago in reply to Stanley Dai

Guru 317260 points

The I²C specification measures these times between 30% and 70% of V_DD.

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PCA9548A: I2C Signal Rise Time Test Condition Consult