TS39100/1/2/3/4/5

1A Ultra Low Dropout Voltage Regulator

with Multi-Function

7/13

Version: B07

Application Information (Continue)

Transient Response and 3.3V to 2.5V or 2.5V to 1.8V Conversion

TS39100/1/2/3/4/5 has excellent transient response to variations in input voltage and load current. The device have

been designed to respond quickly to load current variations and input voltage variations. Large output capacitors are

not required to obtain this performance. A standard 10uF output capacitor, preferably tantalum, is all that is required.

Larger values help to improve performance even further. By virtue of its low dropout voltage, this device does not

saturate into dropout as readily as similar NPN base designs. When converting from 3.3V to 2.5V or 2.5V to 1.8V, the

NPN based regulators are already operating in dropout, with typical dropout requirements of 1.2V or greater,. To

convert down to 2.5V or 1.8V without operating in dropout, NPN based regulators require an input voltage of 3.7V at

the very least. The TS3910x regulator will provide excellent performance with an input as low as 3.0V or 2.5V

respectively. This gives the PNP based regulators a distinct advantage over older, NPN based linear regulators.

Power Dissipation

From under curves, the minimum area of copper necessary for the par to operate safely can be determined. The

maximum allowable temperature rise must be calculated to determine operation along which curve.

Copper area lay out information

Determine the power dissipation requirements for the design along with the maximum ambient temperature at which

the device will be operated. Refer to power dissipation with copper area curve, which shows safe operating curves for

three different ambient temperatures with 25

be determined by knowing the maximum power dissipation required.

If we used a 5.0V output device and a 6V input at an output current of 350mA, then the power dissipation is as follows:

If the maximum ambient temperature is 85

the required area of copper is 80mm