TPS2388: SDA lines stuck low.

vignesh M6

Part Number: TPS2388
Other Parts Discussed in Thread: ISO1541

Hi sir,

As per our application, we are using TPS2388 IC for PoE communication. I connected the PSE controller and microcontroller with non - isolation system(i.e - SDAI and SDAO shorting together). If i shorting SDAI and SDAO to SDA line that time my SDA pin stuck LOW. Even I give 10K pull up on SDAO line also.

I isolate I2C connection between the PSE controller and Microcontroller, I2C both pins are getting High, due to pullup.

over 5 years ago

0 Darwin Fernandez over 5 years ago

TI__Mastermind 41760 points

Hi Vignesh,

We have used our PSE controllers in this configuration in the past with no issues. To give you some context, we shorted SDAI with SDAO and pulled it up to 3.3V rail with a 4.7k resistor that goes to the isolator. The isolator we used was a bidirectional isolator ISO1541. This worked fine and we were able to read the registers with the PSE GUI.

0 vignesh M6 over 5 years ago

Intellectual 300 points

Hi,

I solved this issue. due to VPWR UVLO the SDAO line getting low.

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TPS2388: SDA lines stuck low.