LTC6820 as I2C?!

Hello. If connecting miso-mosi pins to each other, can ltc6820 operate in I2C bus system?


  • 0
    •  Analog Employees 
    on Dec 9, 2019 2:34 AM

    Moved to its proper community Interface and Isolation.

  • +1
    •  Analog Employees 
    on Dec 9, 2019 6:52 AM

    Hi Hossein

    No. I wouldn't recommend you tie the SPI (MISO/MOSI) to form a I2C protocol. There are many reason as why it will not work and you must not do this. Below are a few (of many) reasons as why it will not work.

    (a) I2C protocol are open drain (or sometimes referred as open collector), while SPI are not (from a specification point of view)

    (b) MISO/MOSI are unidirectional, it requires chip select and a clock in order to work (i.e. in conjunction with data, that's inside the device thru the microcontroller's/state machine) for enabling the data transferring of information. Where I2C have no chip select and the SDA line is bi-directional. Also the I2C data transfer are decoded from the respected device by means of the address ID (which form part of the payload).

    (c) I2c and SPI protocol have their uniqueness in how the setup, initiating, the start/stop and the data sequencing. Hence the protocol are unique and are different.

    (d) I2C can be daisy chain with unique addressing ID headers in the payload. while SPI data are common and are selected only by the chip select to appropriate device prior (and during) any communication (transferring of information).

    As you can see, from above examples, the reasons as why you can't do this..... Bottom line, the protocol are incompatible.

    Hope this helps.