USB-Serial: I2C Lines Pull-Up Resistor – KBA89374

[Anonymous]

Version: *A

Translation - Japanese: USB-シリアル：I2Cラインプルアップ抵抗　—　KBA89374 - Community Translated (JA)

Question: Do you have to connect the external pull-up resistors for the I²C lines of a USB-Serial Bridge Controller device?

Answer:

Yes, the SCLK and SDATA lines of the I²C interface of the USB-Serial Bridge Controller device are open drain pins. External pull-up resistors must be connected on these I²C lines. These pull-up resistors should be connected to the V_DDD supply. Recommended values for the pull-up resistors are shown in Table 1.

Table 1. Recommended Values for the Pull-up Resistors

                                                             

I2C Operating Frequency	Resistor Value
100 kHz	4.7 KΩ
400 kHz	2.2 KΩ