SLR1085 Datasheet, PDF (6/10 Pages) Sangdest Microelectronic (Nanjing) Co., Ltd – Current Limiting and Thermal Protection

Technical Data
Data Sheet N1585, Rev. -
SLR1085
3A Low Dropout Positive Regulator
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 SLR1085 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 SLR1085 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 (V -V ).
OUT IN OUT
The maximum power dissipation is:
(T_J-max - T_A)
P_MAX =
R_ΘJA
Where T is the maximum allowable junction temperature (125°C), and T is the ambient temperature
J-max
A
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
• China - Germany - Korea - Singapore - United States •
• http://www.smc-diodes.com - sales@ smc-diodes.com •