User's Manual l TQMa335xL UM 0101 l © 2019, TQ-Systems GmbH
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5.4
Protection against external effects
As an embedded module the TQMa335xL is not protected against dust, external impact and contact (IP00).
Adequate protection has to be guaranteed by the surrounding system.
5.5
Thermal management
To cool the TQMa335xL, a maximum of 2 W have to be dissipated.
The power dissipation originates primarily in the AM335x and the DDR3L SDRAM.
The power dissipation mainly depends on the software used and can vary according to the application.
It is the customer’s responsibility to define a suitable cooling method for his use case.
In most cases passive cooling should be sufficient.
For further information see Texas Instruments Application Notes (4), (5).
Attention: Destruction or malfunction, TQMa335xL cooling
The AM335x belongs to a performance category in which a cooling system is essential.
It is the user’s sole responsibility to define a suitable heat sink (weight and mounting position)
depending on the specific mode of operation (e.g., dependence on clock frequency, stack height,
airflow, and software).
Particularly the tolerance chain (PCB thickness, board warpage, BGA balls, BGA package, thermal pad,
heatsink) as well as the maximum pressure on the AM335x must be taken into consideration when
connecting the heat sink, see (5). The AM335x is not necessarily the highest component.
Inadequate cooling connections can lead to overheating of the TQMa335xL and thus malfunction,
deterioration or destruction.
5.6
Structural requirements
The TQMa335xL has to be soldered on the carrier board. Please contact
for soldering instructions (10).
6.
SAFETY REQUIREMENTS AND PROTECTIVE REGULATIONS
6.1
EMC
The TQMa335xL was developed according to the requirements of electromagnetic compatibility (EMC). Depending on the target
system, anti-interference measures may still be necessary to guarantee the adherence to the limits for the overall system.
Following measures are recommended:
•
Robust ground planes (adequate ground planes) on the printed circuit board
•
A sufficient number of blocking capacitors in all supply voltages
•
Fast or permanent clocked lines (e.g., clock) should be kept short; avoid interference of other signals by distance and/or
shielding besides, take note of not only the frequency, but also the signal rise times
•
Filtering of all signals, which can be connected externally (also "slow signals" and DC can radiate RF indirectly)
6.2
ESD
In order to avoid interspersion on the signal path from the input to the protection circuit in the system, the protection against
electrostatic discharge should be arranged directly at the inputs of a system.
As these measures always have to be implemented on the carrier board, no special preventive measures were planned on the
TQMa335xL.
Following measures are recommended for a carrier board:
•
Generally applicable:
Shielding of the inputs (shielding connected well to ground / housing on both ends)
•
Supply voltages:
Protection by suppressor diode(s)
•
Slow signal lines:
RC filtering, Zener diode(s)
•
Fast signal lines:
Integrated protective devices (e.g., suppressor diode arrays)
6.3
Operational safety and personal security
Due to the occurring voltages (
≤
3.3 V DC), tests with respect to the operational and personal safety haven’t been carried out.
