AIC1747
APPLICATION INFORMATION
ꢀ
conductivity is used, the junction temperature
will be low even when large power dissipation
applies.
INPUT-OUTPUT CAPACITORS
Linear regulators require input and output
capacitors to maintain stability. Input capacitor at
1µF with 1uF output capacitor is recommended.
The power dissipation across the device is
P = IOUT (VIN-VOUT).
POWER DISSIPATION
The maximum power dissipation is:
The AIC1747 obtains thermal-limiting circuitry,
which is designed to protect the device against
overload condition. For continuous load
(TJ-max - TA )
PMAX =
RθJA
Where TJ-max is the maximum allowable junction
temperature (150°C), and TA is the ambient
temperature suitable in application.
condition,
maximum
rating
of
junction
temperature must not be exceeded. It is
important to pay more attention in thermal
resistance. It includes junction to case, junction
to ambient. The maximum power dissipation of
AIC1747 depends on the thermal resistance of
its case and circuit board, the temperature
difference between the die junction and ambient
air, and the rate of airflow. The rate of
temperature rise is greatly affected by the
mounting pad configuration on the PCB, the
board material, and the ambient temperature.
When the IC mounting with good thermal
As a general rule, the lower temperature is, the
better reliability of the device is. So the PCB
mounting pad should provide maximum thermal
conductivity to maintain low device temperature.
GND pin performs a dual function for providing
an electrical connection to ground and
channeling heat away. Therefore, connecting
the GND pin to ground with a large pad or
ground plane would increase the power
dissipation and reduce the device temperature.
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AIC [ ANALOG INTERGRATIONS CORPORATION ]
