TS39153CZ550 Datasheet, PDF (6/12 Pages) Taiwan Semiconductor Company, Ltd – 1.5A Ultra Low Dropout Voltage Regulator with Multi-Function

TS39150/1/2/3
1.5A Ultra Low Dropout Voltage Regulator
with Multi-Function
Application Information (Continue)
Enable Input
TS39151/2/3 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
TTL/CMOS compatible thresholds for simple interfacing with logic interfacing. EN may be directly tied to V_IN and pulled
up to the maximum supply voltage.
Error Flag
TS39151 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
shutdown conditions. A pull-up resistor from error flag to either V_IN or V_OUT is required for proper operation. For
information regarding the minimum and maximum values of pull-up resistance, refer the graph as follow:
Transient Response and 3.3V to 2.5V or 2.5V to 1.8V Conversion
TS3915x 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 TS3915x 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.
Output Sense
The fixed voltage regulator versions (TS39153) is connected to the output pin of the regulator. In critical applications,
small voltage drops are caused by the resistance (Rp) of PC traces between the regulator and the load. These may
be eliminated by connecting the sense pin to the output at the load as follow:
(Kelvin Sense Connection).
Typical Application Circuit
2.5V/1.5A Regulator
2.5V/1.5A Regulator with Error Flag
6/12
Version: D07