Chapter 4
Signal Connections
PCI-4451/4452/4453/4454 User Manual
4-16
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PCI-4453
The analog output signals for the PCI-4453 are +DAC0OUT, AO_SHLD0,
+DAC1OUT, and AO_SHLD1. +DAC0OUT and AO_SHLD0 are the
voltage output signal and its return for analog output channel 0.
+DAC1OUT and AO_SHLD1 are the voltage output signal and its return
for analog output channel 1.
AO_SHLD0 and AO_SHLD1 are connected to AOGND through a
common-mode choke. AOGND is not directly available at the analog
connector. Instead, you can use CGND as a general ground tie point to your
PCI-4453 if necessary, but connecting CGND to other earth-connected
grounds is not recommended. Remember to connect AO_SHLDx to your
ground tie point.
The PCI-4453 has two identical analog output channels. One analog output
channel is illustrated in Figure 4-7.
Figure 4-7.
Analog Output Channel Block Diagram for the PCI-4453
The analog output stage is single-ended only. This means that the devices
or loads receiving signals should not have their signal returns connected to
any earth-connected grounds external to the PCI-4453.
Analog Power Connections
Two pins on the analog I/O connector 5 V (+4.65 to +5.25 VDC at
1.0 A) from the computer power supply through a self-resetting fuse. The
fuse resets automatically within a few seconds after an overcurrent
condition is removed. These pins are referenced to DGND, and you can use
them to power external analog accessories like the BNC-214X.
Caution
Do not connect these +5 V power pins directly to analog ground, digital ground,
or to any other voltage source on the PCI-445X or any other device. Doing so can damage
the PCI-445X device and the computer. National Instruments is not liable for damages
resulting from such a connection.
Common-Mode
Choke
D/A
Converter
20
Ω
100 k
Ω
Buffer
Mute
+DAC
XOUT
AO_SHLD
X
Gain = 0 dB