AIC1733_15 Datasheet, PDF (10/13 Pages) Analog Intergrations Corporation – 500mA, Low Dropout Linear Regulator with Shutdown

AIC1733
CURRENT LIMIT (I_IL)
AIC1733 includes a current limiting, which
monitors and controls the maximum output
current if the output is shorted to ground. This
can protect the device from being damaged.
THERMAL PROTECTION
Thermal sensor protects device when the
junction temperature exceeds T_J= +155ºC. It
APPLICATION INFORMATION
INPUT-OUTPUT CAPACITORS
Linear regulators require input and output
capacitors to maintain stability. Input capacitor at
1µF with a 4.7uF aluminum electrolytic output
capacitor is recommended.
NOISE BYPASS CAPACITOR
0.1µF bypass capacitor at BP pin reduces output
voltage noise. And the BP pin has to connect a
capacitor to GND.
POWER DISSIPATION
The maximum power dissipation of AIC1733
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 conductivity is used,
the junction temperature will be low even when
large power dissipation applies.
signals shutdown logic, turning off pass transistor
and allowing IC to cool down. After the IC’s
junction temperature cools by 15ºC, the thermal
sensor will turn the pass transistor back on.
Thermal protection is designed to protect the
device in the event of fault conditions. For a
continuous operation, do not exceed the absolute
maximum junction-temperature rating of T_J=
150ºC, or damage may occur to the device.
The power dissipation across the device is
P = I_OUT (V_IN-V_OUT).
The maximum power dissipation is:
PMAX = ^{(TJ − TA)}
(RθJB + RθBA)
Where T_J-T_A is the temperature difference
between the die junction and the surrounding air,
Rθ_JB is the thermal resistance of the package,
and Rθ_BA is the thermal resistance through the
PCB, copper traces, and other materials to the
surrounding air.
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 of 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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