PCA9306: PCA9306 design issue

Dilip Namdeo Mohol

Intellectual 1965 points

Part Number: PCA9306

I am using PCA9306 in my design (ASR9K Blackbolt RP). I notice strange behavior. I2C2 signals have 1.45V when device is disabled, and 2V when device is enabled. Is that expected? Is the following circuit correct? Note that I2C2 is pulled up to 3.3V_AUX and I2C1 is pulled up to 1.8V. Please share your comment asap.

PCA.docx

over 5 years ago

0 BOBBY over 5 years ago

TI__Guru 71790 points

Hello Dilip,

It looks like in your schematic, you have the device set up improperly. Figure 7 of the datasheet shows the commonly WRONG set up customers use. Figure 6 is what you should have designed it for instead. Section 8.1.2 describes why your set up is bad.

-Bobby

0 Tilak Gaitonde over 5 years ago in reply to BOBBY

Prodigy 10 points

Understood. Thank you.

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PCA9306: PCA9306 design issue