MAC-SA5X User’s Guide
DS50002938A-page 16
2019 Microchip Technology Inc.
Solder
The MAC is a lead-free device. See the data sheet for RoHS compliance. Use SAC305
solder Sn96.5/Ag3.0/Cu0.5 or similar for hand-soldering to a PCB.
Heat Sink and Thermal Management
To allow the highest ambient operating temperature for the SA5X, it is recommended
that the bottom (baseplate) of the SA5X have good thermal contact with the mounting
surface (no air gap between baseplate and external PCB/heat sink etc). To ensure
good thermal contact, Microchip recommends that the SA5X is secured using (4) 2-56
screws. The location of the four screw holes is shown in
If the baseplate temperature rises above +75°C, the physics package heater shuts
down as control point temperatures are exceeded and the unit temperature coefficients
increase. The unit eventually loses lock above +75°C.
When practical, it is recommended to monitor the baseplate temperature with a ther-
mocouple to ensure it remains below +75°C. Alternatively, one may query the telemetry
parameter
Temperature
to get a rough estimate of the external baseplate tempera-
ture. The
Temperature
parameter is measured internally on the PCB and is generally
~10°C to 15°C warmer than the actual baseplate temperature.
It is also important to maintain a uniform temperature into the baseplate of the SA5X
through its mounting points. A thermal pad or thermal grease may improve thermal
conductivity between a heat sink and the MAC's outer case.
mechanical drawing for a thermal pad.
FIGURE 2-2:
ICD 172-00054-000 Thermal Pad.
CAUTION
To avoid damage to the SA5X, the mounting screws must not penetrate the unit by
more than 0.11 in. (2.79 mm).
WARNING
To avoid the possibility of a burn, mount the SA5X to a heat-dissipating surface. The
SA5X operates at a temperature that is hot to the touch and may cause handling dis-
tress.
Содержание SA5 Series
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