System Power Distribution
Delivering power
Grablink Quickpack CFA (PCI) and Grablink Quickpack CFA PCIe are capable of delivering power to 12V external devices attached on the external System connectors. The +12V output power originates directly from the +12V rail connectors for both boards. It is protected against accidental short circuits by a Polymer PTC device that has the following characteristics.
Polymer PTC device characteristics
System connector +12 output - Polymer PTC device |
Min |
Typ. |
Max |
Units |
Hold current at 20°C / 68°F |
|
|
0.5 |
A |
Hold current at 50°C / 122°F |
|
|
0.4 |
A |
Hold current at 70°C / 158°F |
|
|
0.33 |
A |
Trip current at 20°C / 68°F |
1.0 |
|
|
A |
Max time to trip at 8 A |
|
|
0.1 |
s |
The maximum allowed output current for Grablink Quickpack CFA (PCI) and Grablink Quickpack CFA PCIe is actually the hold current of the Polymer PTC device for a worst case Polymer PTC device temperature at 70°C / 158°F:
Maximum allowed output current for Polymer PTC device
Parameter |
Min |
Typ. |
Max |
Units |
SYSTEM connector +12V output current |
|
|
0.33 |
A |
SYSTEM connector +5V output current |
|
|
0.71 |
A |
Grablink Quickpack CFA (PCI) and Grablink Quickpack CFA PCIe are capable of delivering power to 5V external devices attached on the external System connectors. The +5V supply pins of the PCI connector from the Grablink Quickpack CFA (PCI) provide the output power. The +12V supply pins of the PCI Express connector from the Grablink Quickpack CFA PCIe provide the output power through a regulated DC/DC converter. It is protected against accidental short circuits by a Polymer PTC device that has the following characteristics.
Polymer PTC fuse characteristics
System connector +5V output - Polymer PTC fuse |
Min |
Typ. |
Max |
Units |
Hold current at 20°C / 68°F |
|
|
1.1 |
A |
Hold current at 50°C / 122°F |
|
|
0.87 |
A |
Hold current at 70°C / 158°F |
|
|
0.71 |
A |
Trip current at 20°C / 68°F |
2.2 |
|
|
A |
Max time to trip at 8 A |
|
|
0.3 |
s |
Delivering isolated power
Grablink Quickpack CFA (PCI) and Grablink Quickpack CFA PCIe are capable of delivering isolated power to 5V external devices attached on either internal or external System connectors. The +12V supply pin of both boards provides the isolated 5V output power through an isolated non-regulated 2W DC/DC converter that has the following characteristics.
2W DC/DC characteristics
Parameter |
Min |
Typ. |
Max |
Units |
DC/DC output current |
|
|
0.40 |
A |
DC/DC load regulation |
|
|
±8 |
% |
Isolation voltage |
500 |
|
|
VACRMS |
The DC/DC converter output for Grablink Quickpack CFA (PCI) and Grablink Quickpack CFA PCIe is protected against accidental short circuits by a Polymer PTC device that has the following characteristics.
Polymer PTC fuse characteristics
System connector +5V output - Polymer PTC fuse |
Min |
Typ. |
Max |
Units |
Hold current at 20°C / 68°F |
|
|
0.5 |
A |
Hold current at 50°C / 122°F |
|
|
0.4 |
A |
Hold current at 70°C / 158°F |
|
|
0.33 |
A |
Trip current at 20°C / 68°F |
1.0 |
|
|
A |
Max time to trip at 8 A |
|
|
0.1 |
s |
The maximum allowed DC/DC output current for both boards is the hold current of the Polymer PTC device for a worst case temperature at 70°C / 158°F. Up to 80 mA of the DC/DC output current is consumed by the on-board internal circuits of the isolated IO lines IsoA1 and IsoA2. The maximum allowed output current available on the isolated 5V power output on the System connectors is as follows.
Maximum allowed output current for Polymer PTC device
Parameter |
Min |
Typ. |
Max |
Units |
System connector +12V output current |
|
|
0.25 |
A |
Note. Any short circuit or overload on the isolated 5V power output will affect the IsoA1 and IsoA2 lines.