Technical Data

800mA Low Dropout Positive Regulator

Data Sheet N1576, Rev. -

• China - Germany - Korea - Singapore - United States •

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SLR1117A

Application Information

INPUT-OUTPUT CAPACITORS

Linear regulators require input and output capacitors to maintain stability. Input capacitor at 10μF with a 10μF

aluminum electrolytic output capacitor is recommended.

POWER DISSIPATION

The SLR1117A obtains thermal-limiting circuitry, which is designed to protect the device against overload

condition. For continuous load 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 SLR1117A 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:

Where T

J-max

is the maximum allowable junction temperature (125°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.

Application Examples