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PCA6107: PCA6107

Part Number: PCA6107

Hi Team

I am using a 8bit I2C IO expander part no PCA6107

below are my queries

1) What is the default stae/power up condition for all IO pins P0-P7 ? Inputs with High impedance /High state /Low state ??

2) Is P0 IO pin only open drain?

3) Or P0-P7 all IO pins opendrain do all these IO pins need pull ups or just P0 IO pin only



  • Hi Sanosh,

    The default setting at power up is for all of the inputs to be configured as high-impedance inputs.

    Only the P0 port is designed solely to be open drain, but the other ports could act as an open drain output if you controlled them properly. That is, you could set their output value to be 0, then configure them as outputs to drive low levels and as inputs in order to achieve high levels.

    Outputs acting as open-drain would need pull-ups, but pull-ups would not be needed for push-pull outputs. (Note that pull-ups can be useful when the ports are configured as inputs as well, since they will help to establish a default logic level and help to avoid a higher current consumption case that could occur if the inputs are biased to a mid-level voltage.)