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http://www.union-ic.com Rev.04 Feb.2014

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UM153xx/UM154xx

Typical Application Circuit

GND

VOUT

VIN

1

μF(Ceramic)

1

μF(Ceramic)

UM153xx

GND

VOUT

VIN

1

μF(Ceramic)

1

μF(Ceramic)

UM154xx

EN

off

on

Applications Information

Output Capacitance and Transient Response

The UM153xx/UM154xx series regulators are designed to be stable with a wide range of output

capacitors. The ESR of the output capacitor affects stability, most notably with small capacitors. A

minimum output capacitor of 1μF with an ESR of 0.3Ω or less is recommended to ensure stability.

The device’s output transient response will be a function of output capacitance. Larger values of

output capacitance decrease the peak deviations and provide improved transient response for

larger load current changes. Extra consideration must be given to the use of ceramic capacitors.

The X5R and X7R dielectrics result in more stable characteristics and are more suitable for use as

the output capacitor. The X7R type has better stability across temperature, while the X5R is less

expensive and is available in higher values.

Thermal Protection

Thermal protection disables the output when the junction temperature rises to approximately

+160°C allowing the device to cool. When the junction temperature cools to approximately

+140°C the output circuit is again enabled.