TAS2505-Q1: Question about I2C pull-up resistor value

Iris Shen

Expert 4002 points

Part Number: TAS2505-Q1
Other Parts Discussed in Thread: TAS2505

Hi team,

I'd like to know how to calculate the pull-up resistor for TAS2505 I2C SDA and SCL.

My customer wants to pull I2C up to IOVDD=3.3V with 4.7KΩ. The schematic in datasheet is 2.7K. Is it OK to use 4.7K?

Thanks!

over 2 years ago

0 Arthur Brown over 2 years ago

TI__Mastermind 21265 points

Hi Iris,

4.7k is within reason for a I2C pullup resistor, but it will depend on the bus speed and the capacitance, the TAS2505 I2C interface is 10pF. you will need to consider the capacitance of any other device on the I2C bus.

This document explains how to calculate the maximum pullup that can be used: /cfs-file/__key/communityserver-discussions-components-files/6/I2C-Bus-Pullup-Resistor-Calculation.pdf

Regards,
Arthur

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TAS2505-Q1: Question about I2C pull-up resistor value