Can USB-6009 digital output (open collector) external pull-up use its on board external +2.5 V output?

[Cathymin]

Can USB-6009 digital output (open collector) external pull-up use its on board external +2.5 V output?

Hello,

I want to config USB-6009 digital output to have +2.5 V as high and 0 V as low digital output. I know I can config USB-6009 digital output to open collector with external pull-up resistor, which can be applied with +2.5 V power source.

My question is: Can I use USB-6009 on board +2.5 V output as the pull-up resistor power source? What resistance is a good number for the pull-up resistor if I can use this configuration?

Thank you very much for the help,

Cathy

[John_P1 · Accepted solution]

Hi Cathy,

The USB 6008 digital front end looks like this:

So, there is actually a 4.7 kOhm internal pullup resistor to 5V when the device is configured for open collector.

If you want to output 0-2.5 V, I would look into using a 4.7 kOhm bias resistor between DO and Ground (depending on the rest of your circuit).

Best Regards,

[Cathymin]

Thank you very much John.