TS39154 Datasheet, PDF (3/7 Pages) Taiwan Semiconductor Company, Ltd – 1.5A Ultra Low LDO with Enable

TS39154
1.5A Ultra Low LDO with Enable
Pin Description
Pin Configuration
Enable
Input
Ground
Output
Feed Back (adjustable)
Pin Description
TTL/COMS compatible input. Logic high is enable; logic low or open is shutdown
Unregulated input: +16V maximum supply
Ground: Ground pin and TAB / heat sink are internally connected.
Regulator output
Adjustment input: Feedback input. Connect to resistive voltage-divider network.
Functional Diagram
Application Information
The TS39154 is high performance with low dropout voltage regulator suitable for moderate to high current and voltage
regulator application. Its 700mV dropout voltage at full load and over temperature makes it especially valuable in
battery power systems and as high efficiency noise filters in post regulator applications. Unlike normal NPN transistor
design, where the base to emitter voltage drop and collector to emitter saturation voltage limit the minimum dropout
voltage, dropout performance of the PNP output of these devices is limited only by low V_CE saturation voltage.
The TS39154 is fully protected from damage due to fault conditions. Linear current limiting is provided. Output current
during overload conditions is constant. Thermal shutdown the device when the die temperature exceeds the maximum
safe operating temperature. Transient protection allows device 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 TS39154 is requires an output capacitor to maintain stability and improve transient response is necessary. The
value of this capacitor is dependent upon the output current, lower currents allow smaller capacitors. TS39154 output
capacitor selection is dependent upon the ESR of the output capacitor to maintain stability. When the output capacitor
is 10uF or greater, the output capacitor should have an ESR less than 2Ω. This will improve transient response as well
as promote stability. Ultra low ESR capacitors (<100mΩ), such as ceramic chip capacitors, may promote instability.
These very low ESR levels may cause an oscillation and/or under damped transient response. A low ESR solid
tantalum capacitor works extremely well and provides good transient response and stability over temperature
aluminum electrolytes can also be used, as long as the ESR of the capacitor is <2Ω. 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.
3/7
Version: D08