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I2CHW Voltage | Cypress Semiconductor

I2CHW Voltage

Summary: 2 Replies, Latest post by danaaknight on 24 Sep 2014 06:57 AM PDT
Verified Answers: 0
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uranuscc's picture
7 posts


Can anyone tell me how to set I2CHW UM operating voltage to 3.3V or 5V? I set my PSoC1 system power setting to 5V, but the i2cHW still operates at 3.3V. I didn't find anywhere to change the i2c voltage and hope anyone can help out.



user_460349's picture
1362 posts

Do you have pull up resistor to VCC on the 2 I2C pins? what is the voltage on the other side of the resistor?

user_14586677's picture
7646 posts

The logic high level for I2C is set by the Vdd supply for

the pullup R's. If you are using internal pullups they get

powered by whatever the PSOC Vdd is. If you use external

pullups and terminate them to 3.3V, noise margin in.

this situation significantly reduced. The min "1" level is .7 x Vdd




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