Where do you position the LTC4311 I2C extender when using a TCA9548A MUX breakout (8)

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UncleBillVT
 
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Where do you position the LTC4311 I2C extender when using a TCA9548A MUX breakout (8)

Post by UncleBillVT »

Good day,

I suspect that the extender / terminator (LTC4311 I2C extender) has to go between the MUX (TCA9548A MUX breakout (8) ) and the sensor but this will be solar powered project so I am looking at a power budget. It also doesn’t hurt to keep the cost down…

Can the MUX pass the additional power through?

Thanks in advance.

73 de Bill W.

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mikeysklar
 
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Re: Where do you position the LTC4311 I2C extender when using a TCA9548A MUX breakout (8)

Post by mikeysklar »

Probably best to start with it at the beginning since you have not mentioned cable lengths and the MUX just adds confusion with each i2ce device hanging off of it.
Using this board is easy: connect it to your I2C bus at the beginning of the chain (if you don't have a massively long cable, you can also try at the end of the chain). When the chip is powered and enabled, it will watch the SCL and SDA lines. When it sees them being pulled up through the I2C resistors, it will activate and dump in some current to give it a boost thru to the top power rail.
The MUX (TCA9548A) max supply current is 100mA so not a whole lot of current available to the i2c devices.

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