A good PCB layout for the MAX6649MUA+ involves keeping the analog and digital grounds separate, using a solid ground plane, and placing the device close to the battery to minimize noise and voltage drops.
Calibration involves writing the correct values to the device's registers using the I2C interface. Refer to the datasheet for the specific calibration procedure and register addresses.
The maximum cable length for the I2C interface is dependent on the system's noise environment and clock frequency. As a general guideline, keep the cable length below 10 inches (25 cm) to ensure reliable communication.
Yes, the MAX6649MUA+ can operate in a multi-master I2C bus configuration, but ensure that each master device has a unique address and follows the I2C bus arbitration rules to avoid data corruption.
The INT output is an open-drain pin that requires an external pull-up resistor. Connect the INT pin to a GPIO input of your microcontroller and use the interrupt service routine to handle the interrupt events.