© 1999 SEMTECH CORP.

652 MITCHELL ROAD NEWBURY PARK CA 91320

DUAL INPUT

LOW DROPOUT REGULATOR

EZ1580/EZ1581

EZ1582/EZ1583

February 26, 1999

4

TYPICAL APPLICATIONS

(1)(2)

GROUND

GROUND

3.3V POWER IN

2.5V OUT

5V CONTROL IN

C2

10uF

U1

EZ158XCX-2.5

4

3

2

1

5

CONTROL

OUTPUT

GND

SENSE

POWER

C3

68uF

C1

33uF

GROUND

1.5V OUT

3.3V CONTROL IN

2.5V POWER IN

GROUND

C2

10uF

C3

100uF

C1

47uF

U1

EZ158XCX-1.5

4

3

2

1

5

CONTROL

OUTPUT

GND

SENSE

POWER

2.5V OUT

3.3V POWER IN

5V CONTROL IN

GROUND

GROUND

C2

10uF

C1

33uF

C3

68uF

R1

124

R2

124

U1

EZ158XCX

4

3

2

1

5

CONTROL

OUTPUT

ADJ

SENSE

POWER

VREF

2

R

I

1

R

2

R

1

V

V

ADJ

REF

OUT

•

+

ö

ç

è

æ +

=

Adjustable Output Parts

(3)

Fixed Output Parts

NOTES:

(1) Capacitor values are for reference only. Good quality, low ESR tantalum or aluminum electrolytic capacitors

should be used. Increasing the value of the output capacitor will improve the overall transient response.

(2) If the same voltage is input to both POWER and CONTROL, then the dropout voltage will become 1.3V maxi-

mum.

(3) A small (~0.033µF) capacitor can be used to bypass the ADJUST pin to improve transient response, if needed.