TS39503CZ datasheet(7/12 Pages) TSC

7 / 12 page

TS39500/1/2/3

5A Ultra Low Dropout Positive Voltage Regulator

7/12

Version: A07

Application Information (Continue)

Thermal Characteristics

TS39500/1/2/3 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, TA



Output current, IOUT



Output voltage, VOUT



Input voltage, VIN

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.

PD = (VIN – VOUT) x IOUT + VIN x IGND

The heat sink thermal resistance is determined by:

ӨSA = (TJ(MAX) – TA) / PD – (ӨJC + ӨCS)

Where

TJ(MAX) ≤ 125oC and ӨCS is between 0oC and 2oC/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/5A Regulator

2.5V/5A Regulator with Error Flag

TS39503CZ Datasheet(PDF) 7 Page - Taiwan Semiconductor Company, Ltd