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Chapter 3
Signal Connections
©
National Instruments Corporation
3-13
PCI-DIO-96/PXI-6508/PCI-6503 User Manual
This resistor value, 5.7 k
Ω
, provides a maximum of 2.8 V on the DIO line
at power up. You can substitute smaller resistor values to lower the voltage
drop or to provide a margin for V
CC
variations and other factors. However,
smaller values draw more current, leaving less sink current for other
circuitry connected to this line. The 5.7 k
Ω
resistor reduces the amount of
a logic low sink current by 0.8 mA with a 0.4 V output.