TS39300 TSC [Taiwan Semiconductor Company, Ltd], TS39300 Datasheet - Page 4

• Manufacturer Part Number: TS39300
• Description: 3A Ultra Low Dropout Positive Voltage Regulator
• Manufacturer: TSC [Taiwan Semiconductor Company, Ltd]

TS39300
Application Information
The TS39300 is a high performance low dropout voltage
regulator suitable for moderate to high-current voltage
regulator applications. Its 500mV dropout voltage at full
load makes it especially valuable in battery-powered
systems
post-regulator applications. Unlike older NPN-pass
transistor designs, where the minimum dropout voltage
is limited by the base-to-emitter voltage drop and
collector-to-emitter
performance of PNP output of these devices is limited
only by the low V
A trade-off for the low dropout voltage is a varying base
drive requirement.
Application Information
The TS39300 regulator is fully protected from damage
due to fault conditions. Current limiting is provided. This
limiting is linear, output current during overload
conditions is constant. Thermal shutdown disables the
device when the die temperature exceeds the mzximum
safe operating temperature. Transient proection allows
device (and load) survival even when the input voltage
spikes above and below nominal. The output structure
of these regulators allows voltages in excess of the
desired output voltage to be applied without reverse
current flow.
Output Capacitor Requirement
The TS39300 requires an output capacitor to maintain
stability
capacitor selection is important to ensure proper
operation. The TS39300 output capacitor selection is
dependent upon the ESR (equivalent series resistance)
of the output capacitor to maintain stability. When the
output capacitor is 47uF or greater, the output capacitor
should have less than 1Ω of ESR. This will improve
transient response as well as promote instability. The
very low ESR levels may cause an oscillation and/or
underdamped transient response. A low-ESR solid
tantalum capacitor works extremely well
and
and
improve
CE
a
saturation voltage.
high-efficiency
saturation
transient
voltage,
reponse.
noise
filter
4-6
dropout
Proper
in
The TS39300 has excellent transient response to
variationis in input voltage and load current. The device
has 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 47uF 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-based
designs. When converting from 3.3V to 2.5V or 2.5V to
1.8V, the NPN-base regulators are already operating in
dropout, with typical dropout requirements of 1.2V or
greater. To convert down to 2.5V without operating in
dropout, NPN-based regulators require an input voltage
of 3.7V at the very least.
The
performance with an input as low as 3.0V or 2.5V. This
gives the PNP-based regulators a distinct advantage
over older, NPN-base linear regulators.
and provides good transient response and stability over
temperature. Aluminum electrolytics can also be used,
as long as the ESR of the capacitor is ≤1Ω.
The value of the output capacitor can be increased
without limit. Higher capacitance values help to
improve transient response and ripple rejection and
reduce output noise.
Input Capacitor Requirement
An input capacitor of 1uF or greater is recommended
when the device is more than 4 inches away from the
bulk as supply capacitance, or when the supply is a
battery. Small, surface-mount, ceramic chip capacitors
can be is used for the bypassing. Larger values will
help to improve ripple rejection by bypassing the input
to the regulator, further improving the integrity of the
output voltage..
Minimum Load Current
The TS39300 regulator is specified between finite
loads. If the output current is too small, leakage
dominate and the output voltage rises. A 10mA
minimum load current is necessary for proper
regulator.
Transient Response and 3.3V to 2.5V
or 2.5V to 1.8V Conversion
TS39300
regulator
2005/12 rev. A
will
provide
excellent