NIKO L1581D, L1581D-3.3, L1581D-2.5 Datasheet
NIKO-SEM
Dual Input Ultra Low Dropout
Voltage Regulator (ULDO)
GENERAL DESCRIPTION
FEATURES
L1581 Series
TO-252
The L1581 is a positive and very low
dropout voltage regulator with 5A output
current capability. When supplying 2.5V or
2.8V on Motherboards or VGA Card where
both 5V and 3.3V supplies are available,
the superior dropout characteristics of the
L1581 result in reduced heat dissipation
compared to regular LDOs, thus allowing
heat sink reduction. The adjustable version
requires only two external resistors to set
the output. The L1581 features a low
dropout of less than 600mV and offers fast
transient response, remote sense, internal
limiting, thermal shutdown and safe
operating area protection of the output
device.
The L1581 is a five terminal adjustable
voltage regulator available in the popular 5
pin TO-252 packages.
TYPICAL APPLICATION
Adjustable Output Parts
Vin
(2)
L1581X
z Low dropout voltage 600mV at rated load
current
z Remote sense operation
z Fast transient response
z 0.5% voltage reference initial accuracy
z Standard 5 terminal, Low cost TO-252
packages
APPLICATIONS
z 3.3V to 2.8V or 2.5V for Motherboards or
VGA Card
z Spilt plane microprocessor supplies
z Post regulator for switching supplies
35
OUTVin
Vout
Vctrl
C1
330uF
4
CTR'L
C2
10uF
0.033uF
C3
2
SENSE
ADJ
Iadj
Vo = Vref (1+R2/R1) + Iadj x R2
1
Vref
R1
C4
330uF
R2
1
OCT-11-Y02
NIKO-SEM
Fixed Output Parts
Dual Input Ultra Low Dropout
Voltage Regulator (ULDO)
L1581X-2.5
Vin
Vctrl
C1
330uF
C2
10uF
4
CTR'L
OUTVin
SENSE
ADJ
2
L1581 Series
TO-252
35
2.5V Vout
1
C4
330uF
L1581X-3.3
Vin
Vctrl
C1
330uF
C2
10uF
4
CTR'L
2
SENSE
ADJ
35
OUTVin
1
3.3V Vout
C4
330uF
NOTES :
(1) If the same voltage is input to both INPUT and CONTROL, then the dropout voltage will become 1.3V
maximum.
(2) A small (~0.033uF) capacitor can be used to bypass the ADJUST pin to improve transient response, if needed.
(3) 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
OCT-11-Y02
Loading...