Microsemi Inc.

Integrated Products Division

11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570

Page 1

Copyright

© 2000

Rev. 2.0b, 2005-10-25

LX8385x-xx

3A Low Dropout Positive Regulators

TM

®

DESCRIPTION

The LX8385/85A/85B Series ICs are

positive regulators designed to provide 3A

output current. These regulators yield

higher efficiency than currently available

devices with all internal circuitry designed

to operate down to a 1V input-to-output

differential. In each of these products, the

dropout voltage is fully specified as a

function of load current. Dropout is

guaranteed at a maximum of 1.3V

(8385A/B) and 1.5V (8385) at maximum

output current, decreasing at lower load

currents.

In addition, on-chip trimming adjusts the

reference voltage tolerance to 1% maximum

at room temperature and 2% maximum over

the 0 to 125°C range for the LX8385A. The

LX8385B offers 0.8% tolerance at room

temperature and 1.0% maximum over line,

load and temperature. Fixed versions are

also available and specified in the Available

Options table below.

The LX8385/85A/85B Series devices are

pin-compatible

with

earlier

3-terminal

regulators, such as the 117 series products,

but they do require input and output

capacitors. A minimum 10µF capacitor is

required on the input and a 15µF or greater

on the output of these new devices for

stability. Although, these capacitors are

generally included in most regulator designs.

The LX8385/85A/85B Series quiescent

current flows into the load, thereby

increasing efficiency. This feature contrasts

with PNP regulators where up to 10% of the

output current is wasted as quiescent

current.

The LX8385-xxI is specified over the

industrial temperature range of -25°C to

125°C, while the LX8385-xxC / 85A-xxC /

85B-xxC is specified over the commercial

range of 0°C to 125°C.

IMPORTANT:

PRODUCT H I GHLIGHT

*1500µF

6MV1500GX

Sanyo

LX8385A

1%

1%

IN

ADJ

OUT

5V

3.3V

at 3A

1500µF

2x 6MV1500GX

Sanyo

+

+

KEY FEATUR ES

Three-Terminal Adjustable Or

Fixed Output

Guaranteed 1% Voltage

Reference Accuracy Over Line,

Load, And Temperature

(LX8385B)

Guaranteed < 1.5V Headroom At

3A (LX8385)

Guaranteed < 1.3V Headroom At

3A (LX8385A/8385B)

0.015% Line Regulation

0.15% Load Regulation

APPLICATIONS

High Efficiency Linear

Regulators

Post Regulators For Switching

Power Supplies

Battery Chargers

Constant Current Regulators

Graphics & Standard Supplies

Processor I/O Supply

Low Voltage Memory & Chipset

Supplies

PART #

OUT PUT

VOLTAGE

LX8385/85A/85B-00

Adjustable

LX8385/85A/85B-33

3.3V

LX8385/85A/85B-05

5.0V

Table 1

- Available Options

PACKAGE ORDER INFO

DT

Plastic TO-252

(D-Pak) 3-Pin

P

Plastic TO-220

3-Pin

DD

Plastic TO-263

3-Pin

Max Ref

Accuracy

Max Dropout

Voltage

RoHS Compliant

Transition DC: 0532

RoHS Compliant

Transition DC: 0543

RoHS Compliant

Transition DC: 0535

2.0%

1.5V

LX8385-xxCDT

LX8385-xxCP

LX8385-xxCDD

2.0%

1.3V

LX8385A-xxCDT

LX8385A-xxCP

LX8385A-xxCDD

0 to 125

1.0%

1.3V

LX8385B-xxCDT

LX8385B-xxCP

LX8385B-xxCDD

-25 to 125

2.0%

1.5V

LX8385-xxIDT

LX8385-xxIP

LX8385-xxIDD

Note: Available in Tape & Reel. Append the letters “TR” to the part number. (i.e. LX8385-xxCP-TR)