We design a Backplane system with PCA9548A I2C switch, In this design, the I2C switch multiplex I2C between cards. when write 0x00 in register 0 of PCA9548A, and output I2C ports are disable, the I2C signal is OK!
But when wite 0xff in resister 0 of PCA9548A, and output I2C ports are enable, the I2C signal is not OK because the low level of the signal come to 0.7 volt. What can I do to overcome this problem?
I attach I2C signal Image, whan all ports are enable and all ports are disable.