Embedded Solutions
Page 40
Construction and Reliability
PCIe Modules were conceived and engineered for rugged industrial environments. The
PcieBiSerialDb37Lm9 is constructed out of 0.062 inch thick high temperature ROHS
compliant material.
The traces are matched length from the FPGA ball to the IO pin. The analog switches
and termination resistors are located directly under the transceivers and connected with
“zero stub” routing to eliminate unwanted effects from unused options.
Surface mounted components are used. The components are available with
commercial and Industrial temperature ranges. Please order the “ET” version for more
demanding environments. Conformal coating is an option for condensing environments
or for another measure of board protection. Please order the “CC” version.
The PCIe is secured against the chassis with the connectors and front panel. If more
security against vibration is required a chassis with top side support can be used. The
PCIeBiSerialDb37 has a wider keep out than required by PCIe specification to allow use
in industrial chassis and horizontal mount situations.
The power and ground planes are implemented with relatively heavy copper to help with
heat spreading in chassis with limited air flow. The components are spaced to allow for
efficient cooling and power dispersion.
Thermal Considerations
The PcieBiSerialDb37Lm9 design consists of CMOS and similar circuits. The power
dissipation due to internal circuitry is very low. It is possible to create higher power
dissipation with the externally connected logic. If more than one Watt is required to be
dissipated due to external loading; cooling with forced air is recommended. With the one
degree differential temperature to the solder side of the board external cooling is easily
accomplished.
