CONFIDENTIAL
DOC-USR-0259-02
19
______________________________________________________________________________________
Z3 Technology, LLC
♦
100 N 8
th
ST, STE 250
♦
Lincoln, NE 68508-1369 USA
♦
+1.402.323.0702
5.0
THERMAL CONSIDERATIONS
The module requires that heat is removed from the CPU chip and dissipated into the environment in order to
maintain its operating temperature specification. It may be necessary to also remove heat from the memory
IC in some applications. The system designer is responsible for implementing the cooling mechanisms
necessary for any given application.
The CPU IC is the most critical component. Its’ datasheet specifies a junction temperature Tj max of 105°C,
and 3GPP-mode ambient operating temperature of -20° to +60°C.
Proper operation of the module requires that the thermal solution employed is capable of maintaining the
operation temperature within these parameters.
The FPGA on the 30-0103 board also requires careful attention from a thermal design perspective. This
component dissipates a significant amount of heat which could get “trapped” between the CPU module PCB
and the connector PCB.
The system-level designer is responsible to ensure that all components on all boards operate within their
temperature specification. The FPGA specification requires that the die temperature is maintained between
0°C and 100°C. There is a temperature sensor in the FPGA die which is displayed on the encoder’s GUI status
page.
The Z3 design uses an aluminum block to remove heat from the CPU on the module board. This is a heat
pipe
and not a heat
sink
. The heat pipe is efficient at transferring the heat out of the CPU, but it is not
efficient at dissipating the heat. Therefore, it is necessary to use an adequate heat
sink
thermally
connected to the heat
pipe
to remove the heat from the system. For example, the heat pipe could be
thermally connected to the wall of an aluminum enclosure.
The Z3 example design uses thermal pads to conduct heat from the 30-0103 board to the module board and
to the connector board. The intention is that a significant portion of the thermal energy generated at the
30-0103 board is conducted to the module board, where it will be extracted via heat pipe and heat sink.
This is just an example of a method to dissipate heat from the FPGA and should not be deemed sufficient or
adequate for any given application. The system-level application designer must engineer a proper thermal
solution that is fit for the application.
