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BQ27426: SCL stucks low level

Part Number: BQ27426

Tool/software:

In our design, the fuel gauge is always on because it is connected to the battery, pull-up resistors (4k7 ohm) are disabled until the microcontroller launches a measure, so i2c lines are floating we don't use a 1Mohm pull-down.

The i2c bus is connected to the other sensors and I lost the availability to read all of them because SCL was stuck low, the bus only restarts if I unplug the battery.

Resetting uc doesn't have any effect.

Is there any reason this chip could block the i2c bus, if we shut down the chip we could prevent it. 

  • Hello Jorge, 

    Please follow the spec in the datasheet. If the pull up resistors are disconnected from the SDA and SCL lines, then a 1Mohm pull down resistor should be used to avoid a floating input. 

    Regards, 

    Jonny.