TS39303CZ518 Datasheet, PDF (7/12 Pages) Taiwan Semiconductor Company, Ltd – 3A Ultra Low Dropout Voltage Regulator with Multi-Function

TS39300/1/2/3
3A Ultra Low Dropout Voltage Regulator
with Multi-Function
Application Information (Continue)
Thermal Characteristics
TS39300/1/2/3 linear regulators are simple to use, the most complicated design parameters to consider are thermal
characteristics, thermal design requires the following application specification parameters:
 Maximum ambient temperature, T_A
 Output current, I_OUT
 Output voltage, V_OUT
 Input voltage, V_IN
Calculate the power dissipation of the regulator from these numbers and the device parameters from this datasheet,
where the ground current is taken from data sheet.
P_D = (V_IN – V_OUT) x I_OUT + V_IN x I_GND
The heat sink thermal resistance is determined by:
Ө_SA = (T_J(MAX) – T_A) / P_D – (Ө_JC + Ө_CS)
Where T_J(MAX) ≤ 125^oC and Ө_CS is between 0^oC and 2^oC/W. The heat sink may by significantly reduced in
applications where the minimum input voltage is know and is large compared with the dropout voltage and distribute
the heat between this resistor and the regulator. The low dropout properties of vertical PNP regulators allow
significant reductions in regulator power dissipation and the associated heat sink without compromising performance.
When this technique is employed, a capacitor of at least 1uF is needed directly between the input and regulator
ground.
Typical Application Circuit
2.5V/3A Regulator
2.5V/3A Regulator with Error Flag
7/12
Version: B07