TLE42664_15 Datasheet, PDF (12/15 Pages) Infineon Technologies AG – Low Dropout Fixed Voltage Regulator

TLE42664
Application Information
R_thJA,max = (T_j,max – T_a) / P_D
= (150 °C – 105 °C) / 0.479 W
= 93.9 K/W
As a result, the PCB design must ensure a thermal resistance R_thJA lower than 93.9 K/W. By considering
TLE42664G (PG-SOT223-4 package) and according to “Thermal Resistance” on Page 6, at least 300 mm²
heatsink area is needed on the FR4 1s0p PCB, or the FR4 2s2p board can be used.
6.4
Reverse Polarity Protection
TLE42664 is self protected against reverse polarity faults and allows negative supply voltage. External reverse
polarity diode is not needed. However, the absolute maximum ratings of the device as specified in “Absolute
Maximum Ratings” on Page 5 must be kept.
The reverse voltage causes several small currents to flow into the IC hence increasing its junction temperature.
As the thermal shut down circuitry does not work in the reverse polarity condition, designers have to consider this
in their thermal design.
Data Sheet
12
Rev. 1.1, 2014-07-03