TS39103

1A Ultra Low Dropout Voltage Regulator

with Multi-Function

5/8

Version: A08

Application Information (Continue)

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

TS39103 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 TS39103 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.

Error Flag

TS39101/3 versions feature an Error Flag, which looks at the output voltage and signals an error condition when this

voltage drops 5% below its expected value. The error flag is an open-collector output that pulls low under fault

conditions. It may sink 10mA. Low output voltage signifies a number of possible problems, including an over-current

fault (the device is in current limit) or low input voltage. The flag output is inoperative during over temperature

information regarding the minimum and maximum values of pull-up resistance, refer the graph as follow:

Enable Input

TS39103 versions feature an active-high enable (EN) input that allows ON/OFF control of the regulator. Current drain

reduces to “zero” when the device is shutdown, with only micro-amperes of leakage current. The EN input has

up to the maximum supply voltage.