S-1155 Series

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HIGH RIPPLE-REJECTION LOW DROPOUT

HIGH OUTPUT CURRENT CMOS VOLTAGE REGULATOR

© Seiko Instruments Inc., 2007-2015

Seiko Instruments Inc.

1

The S-1155 Series, developed by using CMOS technology, is a positive voltage regulator with a super low dropout voltage,

high-accuracy output voltage and low current consumption.

The S-1155 Series provides the very low dropout voltage and the large output current due to the built-in transistor with low

on-resistance. The S-1155 Series includes an overcurrent protection circuit that prevents the load current from exceeding

the current capacitance of the output transistor, a thermal shutdown circuit that prevents damage due to overheating, and

an inrush current limit circuit to limit the excessive inrush current generated at power-on.

The ON/OFF circuit ensures longer battery life. Compared with the voltage regulators using the conventional CMOS

technology, a large variety of capacitors are available, including small ceramic capacitors

The small package SOT-89-5 realizes high-density mounting.



Features

• Output voltage:

1.0 V to 5.0 V, selectable in 0.05 V step

• Input voltage:

1.5 V to 5.5 V

• Output voltage accuracy:

±1.0% (1.0 V to 1.45 V output product: ±15 mV)

• Dropout voltage:

• Current consumption:

During operation:

70

μA typ., 90 μA max. (3.0 V output product)

During power-off: 0.1

μA typ., 1.0 μA max.

• Output current:

*1

• Input and output capacitors:

A ceramic capacitor of 4.7

μF or more can be used.

• Ripple rejection:

70 dB typ. (1.0 V output product, f = 1.0 kHz)

• Built-in overcurrent protection circuit:

Limits overcurrent of output transistor.

• Built-in thermal shutdown circuit:

Prevents damage caused by heat.

• Built-in inrush current limit circuit:

Limits excessive inrush current at power-on.

• Built-in ON/OFF circuit:

Ensures long battery life.

• Operation temperature range:

Ta =

−40°C to +85°C

• Lead-free, Sn 100%, halogen-free

*2

*1. Attention should be paid to the power dissipation of the package when the output current is large.

*2. Refer to “ Product Name Structure” for details.



Applications

• Constant-voltage power supply for battery-powered device

• Constant-voltage power supply for TV, notebook PC and home electric appliance

• Constant-voltage power supply for portable equipment



Package

• SOT-89-5