Alpha Semiconductor Inc. 1031 Serpentine Lane. Pleasanton, CA 94568 Tel: (925) 417-1391 Fax: (925) 417-1390

Rev. 9/14/99

ALPHA

SEMICONDUCTOR

Excellence in Analog Power Products

α

AS1117

800mA Low Dropout Regulator

SCSI-II Active Terminator

FEATURES

APPLICATIONS

• Guaranteed 800mA Output

• SCSI-II Active Terminator

• Three Terminal Adjustable Or Fixed 1.5V, 2.5V, 2.85V, 3V, 3.3V & 5V

• Portable/ Palm Top / Notebook Computers

• Very Low Quiescent Current

• Battery Chargers

• Low Dropout Voltage Of 1.2 Volts At Full Load

• Disk Drives

• Extremely Tight Load And Line Regulation

• Portable Consumer Equipment

• Very Low Temperature Coefficient

• Portable Instrumentation

• Fixed 2.85V Device For SCSI-II Active Terminator

• SMPS Post-Regulator

• Logic-Controlled Electronic Shutdown

• Internal Overcurrent Limiting & Thermal Overload Protection

• Surface Mount Package SOT-223, TO-252, TO-220, SOT-89, TO-263, & SO-8

PRODUCT DESCRIPTION

The ALPHA Semiconductor AS1117 is a low power positive-voltage regulator designed to meet 800mA output current and comply

with SCSI-II specifications with a fixed output voltage of 2.85V. This device is an excellent choice for use in battery-powered

applications, as active terminators for the SCSI bus, and portable computers. The AS1117 features very low quiescent current and

very low dropout voltage of 1.2V at a full load and lower as output current decreases. AS1117 is available as an adjustable or fixed

2.85V, 3V, 3.3V, and 5V output voltages.

The AS1117 is offered in a 3-pin surface mount package SOT-223, TO-252, TO-220, SOT-89 & TO-263. The output capacitor of

10

µF or larger is needed for output stability of AS1117 as required by most of the other regulator circuits. Use of ALPHA

Semiconductor’s design, processing and testing techniques make our AS1117 superior over similar products.

ORDERING INFORMATION

TO-220

3-PIN

TO-263

3-PIN

SOT-223

3-PIN

PLASTIC

SOIC 8 PIN

SOT-89

3-PIN

TO-252

DPAK

Oper. Temp.

Range

AS1117U

AS1117T

AS1117M3

AS1117S

AS1117M1

AS1117R

-40

°C to +85°C

AS1117U-X

AS1117T-X

AS1117M3-X

AS1117S-X

AS1117M1-X

AS1117R-X

-40

°C to +85°C

X= Output Voltage (X = 1.5V, 2.5V, 2.85V, 3.0V, 3.3V, 5.0, or Blank for Adjustable)

PIN CONNECTIONS

Top View

2

1

3

4

8

7

6

5

ALPHA

AS1117

8-Pin Surface Mount (S)

ALPHA

AS1117

SOT-89 (M1)

1

2

3

ALPHA

AS1117

1

3

2

SOT-223 (M3)

Top View

TO-263-3 (T)

1

ALPHA

AS1117

2

3

Front View

TO-220-3 (U)

ALPHA

AS1117

1

2

3

Front View

TO-252 (R)

ADJ/GND

V

OUT

1

2

3

V

IN

ALPHA

AS1117

ADJ/GND

V

OUT

V

IN

ADJ/GND

V

OUT

V

IN

ADJ/GND

V

OUT

V

IN

GND

N/C

V

OUT

V

OUT

N/C

V

IN

V

IN

V

IN

ADJ/GND

V

OUT

V

IN

Top View

Top View