I am going through the datasheet of the P82B715 I2C extender.
The datasheet says "400 kHz when other system delays permit."
What does this mean? (In the Texas Instruments datasheet they do not mention anything like that.)
Will it affect my application?
- I need a multidrop configuration with 400kHz.
- cable cat 5 (50pF per meter)
- 15 sensor drops, from sensor to sensor 2 feet cat 5 cable
- total bus capacitance buffered = 15x(2/3)x50 = 500pF
- total 16 of P82B715 chips (including MCU board), one P82B715 for each sensor drop
- sensor data are sequentially continuously collected from an MCU at 400KHz
The reason to select this IC is its 2 wire communication. I need a low number of wires for the communication bus.
one sensor drop is one sensor node sensor node = sensor IC + P82B715 IC
Mcu P82B715 IC--> 2ft cable --> 1st sensor node-> 2ft cable -->2nd sensor node-> 2ft cable --> 3rd sensor node -> 2ft cable -->... --> 15th sensor node
so the 15th sensor node is 30ft away from the MCU board
as shown above, other nodes will be connected buffered bus, same as I2C 3, in a parallel way