AIC1702 Datasheet, PDF (11/15 Pages) Analog Intergrations Corporation – Load Regulation, typical - 2mV

AIC1702
 ^{APPLICATION INFORMATION}
The AIC1702 is a high performance linear regulator
that provides low-dropout voltage and low quiescent-
current. The device is available in a fixed output
voltages ranging from 0.8V to 5.0V, and the device can
supply loads up to 350mA.
condition. When the junction temperature exceeds
T_J=135ºC, the thermal-limiting circuit turns off the pass
transistor and allows the IC to cool. For continuous
load condition, maximum rating of junction temperature
must not be exceeded.
Capacitor Selection
Linear regulators require input and output capacitors to
maintain stability. Input capacitor with a 1F, output
capacitor with a 1F ceramic output capacitor is
recommended. When choosing the input and output
ceramic capacitors, X5R and X7R types are
recommended because they retain their capacitance
over wider ranges of voltage and temperature than
other types.
Current Limit
The AIC1702 includes a current limiter, which monitors
and controls the maximum output current. If the output
is overloaded or shorted to ground, this can protect the
device from being damaged.
Dropout Voltage
The minimum input-output voltage differential (dropout)
determines the lowest usable supply voltage. The
dropout voltage is a function of drain-to-source on
resistance multiplied by the load current.
Thermal Protection
The AIC1702 includes a thermal-limiting circuit, which
is designed to protect the device against overload
 ^{APPLICATION CIRCUIT}
Power Dissipation
The maximum power dissipation of AIC1702 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.
The power dissipation across the device is
P = I_OUT (V_IN-V_OUT)
The maximum power dissipation is:
PMAX

(T_J-max - T_A
Rθ _JA
)
Where T_J-max is the maximum allowable junction
temperature (135C), and T_A is the ambient
temperature suitable in application.
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.
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