TPS65218D0: TPS65218D0 SCL and SDA cin Capacitance

Sébastien,

I apologize, but if this value is not in the TPS65218D0 datasheet then I will not be able to locate this information in a reasonable amount of time.

Please refer to the TMDSEVM437X for the recommended I2C pull-up resistor value, which is 2.2kOhms for SCL and SDA when pulled up to 3.3V for I2C communication. There is ID EEPROM and a camera expansion header that also connect to I2C0 bus.

Dear,

I am surprise about this answer. on I2C bus, Bus capacitor is a key parameter to calculate the pull up. All IC I use indicate this Cin value on its spec. 

Regards

Sebastien

Sebastien,

I understand. I am as surprised as you are that the Cin value is not specified. I have asked if any data is available in an internal repository or if the Cin value can be determined by running a simulation, but I cannot guarantee that this will happen for a device that was originally designed prior to 2014.

Based on the information available to me, here are the options that are available to continue debugging the issue:

1.      Decrease the RPU (pull-up resistor) resistance value

• The AM437x EVM uses  2.2kOhms, so this is an approved value
• Maximum strength pull-up for I2C is typically 1kOhms

2.      Modify the software to use Standard-Mode (100kHz)

• If the bus will not work at 400kHz, the only other option without a board spin and laborious analysis is to reduce the speed

Many thanks Brian