Post Go back to editing

LTC6811-2: where is the Parameters value for calculating pull up resister for I2C Master as LTC6811-2?

Category: Hardware
Product Number: LTC6811-2

I want to use LTC6811-2 gpio 4 & 5 as the I2C master. The GPIOs are open drain outputs, so an external pull-up is required on these ports to operate as an I2C. 

External pull-up resistor calculations require the Input voltage low (Vil), Output Voltage low (Vol), and Output current low (Iol), Vcc = 5DC of the master I2C. where this value gets for calculations. 

This is not mentioned in the datasheet. As slave devices, MAX14661 was used. 

also, you can recommend an external pull-up resistor for our master and slave setup.

Thank You in Advance. 

Parents
  • External pull-up resistor calculations require the Input voltage low (Vil), Output Voltage low (Vol), and Output current low (Iol), Vcc = 5DC of the master I2C. where this value gets for calculations. 

    You can find the VIL for the GPIO Pins in the SPI Interface DC Specifications Section under Electrical Characteristics in the Datasheet.


    For VOL you can refer the General DC Specifications section under Electrical Characteristics in the Datasheet.


    The maximum current that GPIO Pins can sink in when GPIO is pulled down is 10mA and you can find this info in the Absolute maximum ratings section in the Datasheet.



    also, you can recommend an external pull-up resistor for our master and slave setup.

    Using a pull-up resistor of 2kOhms should work in your case.

Reply
  • External pull-up resistor calculations require the Input voltage low (Vil), Output Voltage low (Vol), and Output current low (Iol), Vcc = 5DC of the master I2C. where this value gets for calculations. 

    You can find the VIL for the GPIO Pins in the SPI Interface DC Specifications Section under Electrical Characteristics in the Datasheet.


    For VOL you can refer the General DC Specifications section under Electrical Characteristics in the Datasheet.


    The maximum current that GPIO Pins can sink in when GPIO is pulled down is 10mA and you can find this info in the Absolute maximum ratings section in the Datasheet.



    also, you can recommend an external pull-up resistor for our master and slave setup.

    Using a pull-up resistor of 2kOhms should work in your case.

Children
No Data