USB-6501 Output open collector question

[IEvo8]

Hello all,

I am planning on using the usb-6501's digital outputs in open collector mode as a switch to ground to control a FET. I am using a 3.3V rail from my product with a 12k pull-down resistor with one end going to my USB-6001, and the other going to the FET's gate. On the small scale, this works great as the digital output on the DAQ at most sees 275uA. However, I need more channels than what the 6001 can provide and I was hoping to be able to control more than one FET per single line. I was wondering what the limitations were as far as current being driven into the USB-6501's digital ports?

I attached a drawing of the circuit in question

Thanks!

Sean

[NickyNoodle]

Hi IEvo8,

In Open Collector mode, your USB-6501 can sink 0.4 mA without an external pullup resistor or 7.5 mA with an external pullup resistor.

This information can be found on page 2 in the specifications document  which can be found through the product page.