Designed to meet the high-current requirements in industrial and
consumer applications; embedded core, memory, or logic supplies; TVs,
VCRs, and office equipment, the SI-3012KM voltage regulator offers
the reduced dropout voltage and low quiescent current essential for
improved efficiency. This device delivers a regulated output at up to
1 A. Integrated thermal and overcurrent protection enhance overall
system reliability. Devices with fixed output voltages are also available.
Quiescent current does not increase significantly as the dropout
voltage is approached, an ideal feature in standby/resume power systems
where data integrity is crucial. Regulator accuracy and excellent
temperature characteristics are provided by a bandgap reference. An
LS-TTL/CMOS-compatible input gives the designer complete control
over power up, standby, or power down. A pnp pass element provides a
dropout voltage of less than 600 mV at 1 A of load current. Low output
voltages eliminate the need for expensive PWM buck converters. The
low dropout voltage permits more efficient regulation before output
regulation is lost.
This device is supplied in a 5-lead TO-252 style surface-mount
plastic package with ground tab to provide a low-resistance path for
maximum heat dissipation.
FEATURES
1 A Output Current
0.6 V Maximum Dropout Voltage at I
O
= 1 A
Fast Transient Response
1 A Maximum Standby Current
Adjustable 1.28 ~ 15 V Output Voltage
Remote Voltage Sensing
Foldback Current Limiting
Ground Tab for Superior Heat Dissipation
Thermal Protection
APPLICATIONS
TVs, VCRs, Electronic Games
Embedded Core, Memory, or Logic Supplies
Printers and Other Office Equipment
Industrial Machinery
Secondary-Side Stabilization of Multi-Output SMPS
1 A, Low-Dropout, 1.28~15 V Regulator
Data Sheet
27468.43
Always order by complete part number, e.g., SI-3012KM-TL ,
where "-TL" indicates tape and reel.
ABSOLUTE MAXIMUM RATINGS
Input Voltage, V
I
. . . . . . . . . . . . . 17 V
Output Current, I
O
. . . . . . . . . . . . . 1 A*
Enable Input Voltage, V
E
. . . . . . . . . V
I
Junction Temperature, T
J
. . . . +125C
Storage Temperature Range,
T
S
. . . . . . . . . . . . -30C to +125C
* Output current rating is limited by input
voltage, duty cycle, and ambient tempera-
ture. Under any set of conditions, do not
exceed a junction temperature of +125C.
SI-3012KM
Sanken Power Devices
from Allegro MicroSystems
Linear
Regulators
SI-3012KM
1 A, Low-Dropout,
1.28~15 V Regulator
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036
Linear
Regulators
2
FUNCTIONAL BLOCK DIAGRAM
Copyright 2004 Allegro MicroSystems, Inc.
Recommended Operating Conditions
Min
Max
Units
DC Input Voltage
2.4
--
V
DC Output Current
0
1
A
Adjustable Voltage Range
1.28
15
V
Operating Ambient Temp.
-30
+100
C
Operating Junction Temp.
-20
+100
C
Allowable Package Power Dissipation
This data sheet is based on Sanken data sheet SSJ-02017
SI-3012KM
1 A, Low-Dropout,
1.28~15 V Regulator
www.allegromicro.com
Linear
Regulators
3
ELECTRICAL CHARACTERISTICS
at T
A
= +25C, V
O
= 2.5 V adjusted, V
E
= 2 V (unless otherwise noted).
Limits
Characteristic
Symbol
Test Conditions
Min.
Typ.
Max.
Units
Output Voltage
V
O
V
I
= V
O(nom)
+ 1 V, I
O
= 10 mA
--
V
O(nom)
--
V
V
O(off)
V
E
= 0 V
--
--
0.5
V
Output Volt. Temp. Coeff.
a
VO
0C
T
J
100C
--
0.3
--
mV/C
Internal Reference Voltage
V
ref
V
I
= 3.3 V, I
O
= 10 mA
1.24
1.28
1.32
V
Output Short-Circuit Current
I
OM
V
I
= 3.3 V, See note
1.1
--
--
A
Line Regulation
V
O(
VI)
V
I
= 3.3 V ~ 8 V, I
O
= 10 mA
--
--
15
mV
Load Regulation
V
O(
IO)
V
I
= 3.3 V, I
O
= 0 A ~ 1.0 A
--
--
40
mV
Dropout Voltage
V
Imin
- V
O
I
O
= 0.5 A
--
--
0.4
V
I
O
= 1.0 A
--
--
0.6
V
Ground Terminal Current
I
GND
V
I
= 3.3 V, I
O
= 0 mA, V
E
= 2.0 V
--
--
350
A
V
I
= 3.3 V, V
E
= 0 V
--
--
1.0
A
Enable Input Voltage
V
EH
Output ON
2.0
--
--
V
V
EL
Output OFF
--
--
0.8
V
Enable Input Current
I
EH
V
E
= 2.0 V
--
--
40
A
I
EL
V
E
= 0 V
--
0
-5.0
A
Ripple Rejection Ratio
PSRR
V
I
= 3.3 V, 100 Hz
f
120 Hz, I
O
= 100 mA
--
55
--
dB
Thermal Shutdown
T
J
I
O
= 10 mA
135
150
--
C
Typical values are given for circuit design information only.
Note: Output short-circuit current is at point where output voltage has decreased 5% below V
O(nom)
.
SI-3012KM
1 A, Low-Dropout,
1.28~15 V Regulator
www.allegromicro.com
Linear
Regulators
5
APPLICATIONS INFORMATION
Input Capacitor
(C
I
,
22 F). This is necessary either
when the input line includes inductance or when the wiring
is long.
Output Capacitor
(C
O
,
22 F). This device is designed
for use with a very low ESR output capacitor such as a
ceramic capacitor. Output oscillation may occur with an
aluminum capacitor at low temperatures.
ENABLE Input
. The ENABLE (control) input features
an internal pull-down resistor. Leaving this input open
causes the output to turn off.
Parallel Operation.
Parallel operation to increase load
current is not permitted.
TYPICAL CHARACTERISTICS (cont.)
(V
I
= 3.3 V, V
O
= 2.5 V adjusted, T
A
= 25C)
GND Pin Current
Output Voltage Adjustable Resistors
(R1 and R2).
The output voltage can be adjusted by R1 and R2. 24 k
for R2 is recommended.
R1 = (V
O
V
ref
)/(V
ref
/R2)
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