DUAL INPUT
LOW DROPOUT REGULATOR
EZ1580/EZ1581
EZ1582/EZ1583
February 26, 1999
TYPICAL APPLICATIONS(1)(2)
Adjustable Output Parts(3)
U1
EZ158XCX
OUTPUT
1
VREF
SENSE
5
4
3.3V POWER IN
5V CONTROL IN
POWER
3
2.5V OUT
CONTROL
ADJ
R1
124
C1
33uF
C2
10uF
C3
68uF
2
R2
124
GROUND
GROUND
R2
æ
ö
VOUT = V
1+
+ IADJ • R2
REF ç
R1
è
Fixed Output Parts
U1
EZ158XCX-2.5
1
SENSE
5
3.3V POWER IN
POWER
3
2.5V OUT
OUTPUT
4
5V CONTROL IN
CONTROL
GND
2
C1
33uF
C2
10uF
C3
68uF
GROUND
GROUND
U1
EZ158XCX-1.5
1
SENSE
5
4
2.5V POWER IN
POWER
3
1.5V OUT
OUTPUT
3.3V CONTROL IN
CONTROL
GND
2
C1
47uF
C2
10uF
C3
100uF
GROUND
GROUND
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.
4
© 1999 SEMTECH CORP.
652 MITCHELL ROAD NEWBURY PARK CA 91320
SEMTECH [ SEMTECH CORPORATION ]
