TS5218

800mA Ultra Low Dropout

Voltage Regulator with Enable

3/7

Version: A09

Functional Diagram

Application Information

The TS5218 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

The TS5218 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 TS5218 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. TS5218 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.