Kvaser PCIEcan User's Guide
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Kvaser AB, Mölndal, Sweden
— www.kvaser.com
5 The PCIEcan Hardware
For quick and easy installation, all Kvaser PCIEcan boards are plug-and-play boards.
5.1 The Isolated CAN Driver
KVASER’s PCIEcan cards for CAN systems feature up to two CAN controllers. Each CAN-
driver SN65HVD251D is isolated both from the CAN controller and all other CAN drivers. The
CAN driver will get the necessary power from the PCI Express bus via an isolated DC/DC
convert. The isolation between the CAN-controller and the CAN-driver has a delay of
maximum 40 ns in each direction. This will reduce the possible cable length with 20 meter
compared to having no isolation.
Due to human safety, the voltage should never at any part of the PCIEcan board be more
than +/- 50 Volt from the PC-computer chassis ground. Note that the PCIEcan will not secure
this condition itself. If any DSUB pin has an external voltage in the range below +/-500 Volt
from chassis ground this will also be the true voltage at this pin.
Each CAN-driver circuit is protected from short time over voltage like ESD and accidental
short cuts to high voltage. An over voltage /-500 Volt, on any used DSUB pin, will
cause a rapid shortcut to ground. If the applied over voltage do have a high energy source
some PCB wires may burn away in that case.
5.2 CAN Bus Termination
There are no terminating resistors onboard the standard PCIEcan board. However, there is
room available to mount terminating resistors onboard all product versions. These terminating
resistors can also serve as a load between the CAN bus wires; this is needed for the ISO
11898-2 compliant bus drivers to work properly. Please contact our Support Team for detailed
instructions.
