Microsemi Inc.

Integrated Products Division

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

Page 8

Copyright

© 2000

Rev. 2.0b, 2005-10-25

LX8385x-xx

3A Low Dropout Positive Regulators

TM

®

TY PICAL APPLICATIONS

10µF

LX8385x

R1

R2

IN

ADJ

OUT

FIGURE 4

- IMPROVING RIPPLE REJECTION

V

IN

V

OUT

C1

10µF*

150µF

+

+

* C1 improves ripple rejection.

X

R1 at ripple

frequency.

(Note A)

≈

C1*

10µF

LX8385x

R1

R2

1k

IN

ADJ

OUT

FIGURE 5

- 1.2V - 8V ADJUSTABLE REGULATOR

V

IN

V

C2

100µF

+

+

* Needed if device is far from filter capacitors.

⎟

⎠

⎞

⎜

⎝

⎛

+

=

R1

R2

1

1.25V

*V

*

OUT

(Note A)

10µF

1%

LX8385x

100µF

1k

1k

1%

2N3904

IN

ADJ

OUT

FIG URE 6

- 5V REGULATOR W ITH SHUTDOW N

TTL

Output

V

IN

5V

+

+

(note A)

LX8385x

IN

ADJ

OUT

FIGURE 7

- FIXED 3.3V OUTPUT REGULATOR

V

IN

3.3V

10µF Tantalum or

100µF Alum inum

Min. 15µF Tantalum or

100µF Alum inum capacitor. May

be increased without lim it. ESR

Note A:

X)

DROPOUT(MA

OUT

IN(MIN)

V

)

V

(

V

Intended

+

=