Available Output Voltage Levels of the NI 9375

Updated May 27, 2019

Reported In

Hardware

  • NI-9375

Issue Details

I would like to set a specific output voltage at the output of the NI-9375. What are the available voltage levels when the output is ON? Can the module supply 5 V for example?

Solution

Based on its datasheet, the NI-9375 has sourcing outputs, which drive current from the external supply voltage to the digital output when the corresponding channel is ON. (See Figure 1 below.)
 

Figure 1.
 
Since the external power supply voltage (Vsup) range is 6 V to 30 V, the output impedance (R0) is 0.3 Ohm maximum, and the output current (I0) is less than or equal to 500 mA per channel, the Vout = Vsup - I0 x R0 output voltage level in case the channel is ON,  will be in the range of 5.85 V to 30 V depending on the actual value of the supply voltage, output impedance and output current. So 5 V output is not possible within the specified limits. If the digital output is OFF, the output voltage is indeterminate, the output is floating.