Spurs appear on I2C SDA of TSC2007

Di Wang

Other Parts Discussed in Thread: TSC2007

Hi,

I found spurs appear on SDA. Blue is SDA, yellow is SCL. It always happened on the falling edge of 8th or 9th clock, or before the 1st clock cycle. It didn't bring error on data communication, but how it happened? Can I remove it?

Thanks.

over 9 years ago

0 Andy Liu (BMS) over 9 years ago

TI__Guru 52115 points

Let me double check in my office.

0 Andy Liu (BMS) over 9 years ago in reply to Andy Liu (BMS)

TI__Guru 52115 points

Hi Di,

I can see the similar spike in my office using a TSC2007EVM. According to the i2c spec, the SDA signal can only change when the SCL signal is low; when the clock is high the data should be stable. If you take a closer look, the spike only occurs when the SCL is still low, and therefore it is not a real issue.

Andy

0 Di Wang over 9 years ago in reply to Andy Liu (BMS)

Expert 1740 points

Thank you, Andy.
Could tell me where this spike come from and is there any work around circuit to remove it?

0 Andy Liu (BMS) over 9 years ago in reply to Di Wang

TI__Guru 52115 points

Hi Di,

I don't have a perfect answer for you now. I may have to ask the designer for this device for a more detailed answer. Technically, the TSC2007 meets the I2C specifications even though the spike is present. I don't think you have to worry about it.

Andy

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Spurs appear on I2C SDA of TSC2007