Chapter3 MakingSignal Connections
6527User Manual 3-12 ni.com
The followingequation shows the minimum sink curr ent when VOUTis
0.5 V:
Figure3-6. SignalConnections for Driving TTL Voltages
Them aximum powerrating s for the output channels on a 6527 device are
asfollows:
Overcurrent Protection
The 6527 device outputs include circuitry to protect them from currents
over the specified range. Whenexcessive current flows through the relay,
therelay increases resistance. Once the current level drops back under the
specified range,the relays return to normal operation.
Maximum DC voltage across the terminals (VOUT) 60 VDC
Maximum ACvoltage across the terminals (VOUT) 30 VRMS
(42VPeak)
Maximum current (If) 120 mA1
1Withall relays carrying 120 mA and all inputs driven to 28 V,the total power dissipation
canapproach 20 W. The maximum switching capacity in PCI and CompactPCI systems
mustbe derated according to the ambient temperature and cooling capacity of your system
toprevent the device from overheating. (The PXI chassis has built-in fans to handle 25 W
perslot.)
0.5V
35
Ω
------------
5V 0.5V–()
5k
Ω
-----------------------------��13.4 mA=
+5V
RL=5k
VOUT
Isolation
Isolated
Ground
Digital
Logic
390
ToExternal +5 V Supply
If
35
6527