National Instruments cFP-PWM-520 用户手册

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页码 19
© National Instruments Corp.
5
FP-PWM-520 and cFP-PWM-520
Install a 2 A maximum, fast-acting fuse between the external 
power supply and the V
SUP
 terminal on each channel. Install 
a 1 A maximum, fast-acting fuse suitable for the load at the 
V
OUT
terminal. Figure 3 shows fuses where appropriate.
Figure 3.  Wiring the [c]FP-PWM-520
Caution
M
aximum output current for the cFP-PWM-520 
is lower than 1 A if the module is operating in the 
50–70 °C temperature range. Refer to the
section for more information, and select fuses for the V
OUT
 
terminals accordingly.
Pulse-Width Modulator Output Circuit
The [c]FP-PWM-520 output channels are optically isolated from 
the rest of the FieldPoint bank. The channels are sourcing outputs 
with short-circuit protection circuitry. Sourcing current means that 
the V
OUT
 terminal provides a path to a voltage supply. In the ON 
state of the output period, a transistor is turned on between V
SUP
 
and V
OUT
. In the OFF state, this transistor is turned off, allowing 
only a small leakage current to flow.
C V 
V
SUP 
V
OUT 
[c]FP-PWM-520 
COM 
Protected  
Sourcing  
Output 
– 
Load 
5 VDC or 
10–30 VDC 
External
Power Supply
COM 
2 A Max  
User-Supplied  
Fuse 
1 A Max  
User-Supplied  
Fuse