TCA9539-Q1: TCA9539QPWRQ1 current check

I_CC is the current that flows into V_CC and out of GND, and it is measured without a load.

When output pins have a load, the additional load current flows through either V_CC or GND.

Hi Xin,

Did Clemens' response answer your question? 

Regards,

Tyler

Hi Xin,

You can estimate the ICC current draw by only the IC by looking at the operating mode conditions in the datasheet. 

Worst case, the device draws a maximum of 30uA with no load. 

Regards,

Tyler

Hi Xin,

Clemens is correct here.

For example, if you had P00 set to an output HIGH with a 1k load to GND at VCC = 3.3V, then you effectively have a load current roughly equal to 3.3V / 1000 ohm = 3.3mA flowing from VCC out of the P00 pin, to GND. 

For total worst case load current, you would need to conduct a similar analysis for each pin. Each pin load varies dependent on the type of pin configuration INPUT/OUTPUT, and the load that is being driven. Consider that some pins will be high-z inputs, some pins will drive output HIGH, output low, some drive LED's etc. 

Each pin will have some type of current load. The sum of all of these loads is the worst case current.

IF you are trying to see the break point of the device, check the abs. max conditions in the datasheet. I believe the total current that can flow out from VCC or into GND is in the 100's of mA. 

Regards,

Tyler