Hi，I want to ask some questions about I2C on camera expansion connector (J509) AGX xavier(P2822). I have read pinmux spreadsheets and schematic of P2822 ,I want to confirm some details.
Q1: As shown in fig3 PIN75 and PIN77(I2C3_CLK and I2C3DAT) are Bidir, when PIN75 and PIN77 are use to connect max9296 in 1.8V, whether external pull-up resistance is required. Fig1 shows external pull-up resistance of I2C3 are NC. Could you give me some advices whether external pull-up resistance is required?
Q2: As mentioned above，I2C2 and I2C4（PIN87 89 105 107 IN J509） are use to connect max9296 in 1.8V, whether external pull-up resistance is required？
Q3：As shown in fig4，I want to extend I2C using TCA9546，which I2CBUS is better matched？
Q4: As shown in fig4, voltage of I2C2-4 in J509 and max96712 are 1.8V, I think level shift (3.3-1.8v) is ‘Wrong use’?
For external pull-ups, it depends on the total load capacitance on I2C bus. If the load capacitance is much higher than expected, then a stronger pull-up might be necessary. So you can keep the pull-up resistors as NO STUFF in case you want to tune the pull-up strength accordingly.
CAM_I2C is always preferred.
Which doc is the figure 4 from? You can refer to below doc for camera design: