RTOS/TCA8418E: How many sink current maximum in TCA8418E?

Hi Hugo,

The recommended maximum output low-level current for the ROW and COL pins is 25 mA. Is this the data you are trying to find, or do you need something else?

Max

Hello Hugo,

RST is an input and thus is high impedance and very little current.  The only time is really dissipates any power is when the internal pull-up resistor (55 k Ohm typ.) is pull low by the master. Which in that case, all pins of the devices are set as inputs and the power dissipation is drastically reduced. Thus this should be a don’t care state.

INT is open drain so it depends on what you select for the pull-up resistor value for a given Vcc.  The average power consumption should be very little because most of the time the pin is high z until an event triggers the interrupt and turns on the FET. The INT pins meets the same requirements as the SDA/SCL lines which means it has a max resistance of 133.33 Ohms; (V_OL=0.4V)/(I_OL=3mA) = 133.33 Ohms.

I2C is similar to INT and it depends on the pull up resistor used, the Vcc, and the operating frequency.  Generally speaking I2C when lines are idle they are in a high z state and dissipate very little power, until you start to communicate.  NOTE, that the power dissipation only occurs when the SLAVE (TCA8418E) is pulling low, not when the Master is pulling low. SDA/SCL have a max resistance of 133.3 Ohms; (V_OL=0.4V)/(I_OL=3mA) = 133.33 Ohms.

Does this make sense?  Let me know if you have any other questions. 

-Francis Houde