NIKO L1581T, L1581S-3.3, L1581S-2.5, L1581S, L1581-3.3 Datasheet
...
1
Dual Input Ultra Low Dropout
Voltage Regulator (ULDO)
L1581 Series
TO-220,TO-263
JAN-08-Y02
NIKO-SEM
GENERAL DESCRIPTION
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-220 and TO-263 packages.
FEATURES
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-220
and TO-263 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
TYPICAL APPLICATION
Adjustable Output Parts
(2)
Vin
C3
0.033uF
Vout
Iadj
Vo = Vref (1+R2/R1) + Iadj x R2
330uF
C4
L1581X
35
4
2
1
OUTVin
CTR'L
ADJ
SENSE
R2
C2
10uF
R1
C1
330uF
Vctrl
Vref
2
Dual Input Ultra Low Dropout
Voltage Regulator (ULDO)
L1581 Series
TO-220,TO-263
JAN-08-Y02
NIKO-SEM
Fixed Output Parts
330uF
C4
Vctrl
L1581X-2.5
35
4
2
1
OUTVin
CTR'L
ADJ
SENSE
2.5V Vout
C1
330uF
C2
10uF
Vin
330uF
C4
Vctrl
L1581X-3.3
35
4
2
1
OUTVin
CTR'L
ADJ
SENSE
C2
10uF
C1
330uF
Vin
3.3V Vout
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.
3
Dual Input Ultra Low Dropout
Voltage Regulator (ULDO)
L1581 Series
TO-220,TO-263
JAN-08-Y02
NIKO-SEM
ABSOLUTE MAXIMUM RATINGS
z Input Supply Voltage, V
IN
Control Input Voltage, V
CTRL
7V
13.2V
z Operating Junction
Temperature Range, TJ
0 to 125 °C
z Power Dissipation, PD
Internally
Limited
z Storage Temperature
Range, T
STG
-40 to 150 °C
z Thermal Resistance
Junction to Case, θJC
3 °C/W
z Lead Temperature, T
LEAD
(Soldering, 10 Seconds)
260 °C
z Thermal Resistance
Junction to Ambient, θJA
60 °C/W
ELECTRICAL CHARACTERISTICS (
Unless otherwise specified, TJ = 25 °C)
Parameter Symbol Test Conditions Typical Limits
V
CTRL
=4.5V, VIN=2.05V, I
OUT
=10mA 1.237V~1.263V
Reference Voltage
(1)
(Adj. Voltage
Versions)
V
REF
V
CTRL
= 4.5V, 10mA < I
OUT
< 5A,
VIN = 2.05V
1.25V
1.231V~1.269V
Dropout Voltage
(1) (2)
Minimum VIN
VI - VO
V
CTRL
= 4.75V, I
OUT
= 5A
0.54V 0.62V (Max)
V
CTRL
= 5V, V
IN
= V
OUT
＋ 0.8V,
I
OUT
=10mA
± 1%
Output Voltage
(1)
(Fixed Voltage
Versions)
V
OUT
V
CTRL
= 5V, 10mA < I
OUT
< 5A,
V
IN
= V
OUT
＋ 0.8V
V
OUT
± 1.5%
Line Regulation
(1)
REG
(LINE)
V
CTRL
= 4.5V to 12V, VIN = (V
OUT
＋
0.8V) to 5.5V, I
OUT
= 10mA
1.0mV 3.0mV
Load Regulation REG
(LOAD)
V
CTRL
= 4.5V, VIN = (V
OUT
＋0.8V) ,
I
OUT
= 10mA ~ 5A
1.0mV 5.0mV
Thermal Regulation
(6)
REG
(Thermal)
0.002
% / W
0.02% / W
Minimum Load
Current
(4)
IO
V
CTRL
= 5V, VIN = V
OUT
＋0.8V
5mA 10mA
Adjust Pin Current I
ADJ
V
CTRL
= 4.5V, VIN = V
OUT
＋0.8V,
I
OUT
= 10mA
50µA 120µA
Control Pin Current
(3)
I
CTRL
V
CTRL
= 4.5V, VIN = V
OUT
＋0.8V,
I
OUT
= 5A
33mA 120mA
Current Limit ICL
V
CTRL
= 4.5V, VIN = V
OUT
＋0.8V
Δ
V
OUT
= 100mV
5.1A (Min)
Ripple Rejection
Ratio
(5)
RA
V
CTRL
= VIN = 5V, I
OUT
= 5A
80dB 60dB (Min)
Loading...