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 IO = 1 A
Fast Transient Response
1 µA 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, VI. . . . . . . . . . . . . 17 V
Output Current, IO. . . . . . . . . . . . . 1 A*
Enable Input Voltage, VE. . . . . . . . . VI
Junction Temperature, TJ. . . . +125°C
Storage Temperature Range,
TS. . . . . . . . . . . . -30°C to +125°C
* 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 +125°C.
SI-3012
KM
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, 2005 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
For the availability of parts meeting -40°C requirements,
contact Allegro’s Sales Representative.
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 TA = +25°C, VO = 2.5 V adjusted, VE = 2 V (unless otherwise noted).
Limits
Characteristic Symbol Test Conditions Min. Typ. Max. Units
Output Voltage VOVI = VO(nom) + 1 V, IO = 10 mA VO(nom) —V
VO(off) VE = 0 V 0.5 V
Output Volt. Temp. Coeff. aVO 0°C TJ 100°C ±0.3 mV/°C
Internal Reference Voltage Vref VI = 3.3 V, IO = 10 mA 1.24 1.28 1.32 V
Output Short-Circuit Current IOM VI = 3.3 V, See note 1.1 A
Line Regulation VO(VI) VI = 3.3 V ~ 8 V, IO = 10 mA 15 m V
Load Regulation VO(IO) VI = 3.3 V, IO = 0 A ~ 1.0 A 40 m V
Dropout Voltage
V
Imin
- V
O
IO = 0.5 A 0.4 V
IO = 1.0 A 0.6 V
Ground Terminal Current IGND VI = 3.3 V, IO = 0 mA, VE = 2.0 V 350 µ A
VI = 3.3 V, VE = 0 V 1.0 µA
Enable Input Voltage VEH Output ON 2.0 V
VEL Output OFF 0.8 V
Enable Input Current IEH VE = 2.0 V 40 µA
IEL VE = 0 V 0 -5.0 µA
Ripple Rejection Ratio PSRR
V
I
= 3.3 V, 100 Hz f 120 Hz, I
O
= 100 mA
—55 dB
Thermal Shutdown TJIO = 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 VO(nom).
SI-3012KM
1 A, Low-Dropout,
1.28~15 V Regulator
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036
Linear
Regulators
4
TYPICAL CHARACTERISTICS
(VI = 3.3 V, VO = 2.5 V adjusted, TA = 25°C)
Dropout Voltage Low-Voltage Behavior GND Pin Current
Line Regulation Load Regulation
ENABLE Control Voltage
Overcurrent Protection
ENABLE Control Current Thermal Protection
SI-3012KM
1 A, Low-Dropout,
1.28~15 V Regulator
www.allegromicro.com
Linear
Regulators
5
APPLICATIONS INFORMATION
Input Capacitor (CI, 22 µF). This is necessary either
when the input line includes inductance or when the wiring
is long.
Output Capacitor (CO, 22 µF). 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.)
(VI = 3.3 V, VO = 2.5 V adjusted, TA = 25°C)
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 = (VO – Vref)/(Vref/R2)
SI-3012KM
1 A, Low-Dropout,
1.28~15 V Regulator
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036
Linear
Regulators
6
APPLICATIONS INFORMATION (cont.)
Determination of DC Input Voltage. The minimum
input voltage VI(min) should be higher than the sum of the
fixed output voltage and the maximum rated dropout
voltage.
Overcurrent Protection. The SI-3000KM series has a
built-in fold-back type overcurrent protection circuit, which
limits the output current at a start-up mode. It thus cannot
be used in applications that require current at the start-up
mode such as:
(1) constant-current load,
(2) power supply with positive and negative outputs to
common load (a center-tap type power supply), or
(3) raising the output voltage by putting a diode or a
resistor between the device ground and system ground.
Thermal Protection. Circuitry turns off the pass
transistor when the junction temperature rises above 135°C.
It is intended only to protect the device from failures due to
excessive junction temperatures and should not imply that
output short circuits or continuous overloads are permitted.
Heat Radiation and Reliability. The reliability of the
IC is directly related to the junction temperature (TJ) in its
operation. Accordingly, careful consideration should be
given to heat dissipation.
The inner frame on which the integrated circuit is mounted
is connected to the GND terminal (pin 3). Therefore, it is
very effective for heat radiation to enlarge the copper area
that is connected to the GND terminal. The graph illus-
trates the effect of the copper area on the junction-to-
ambient thermal resistance (RθJA).
The junction temperature (TJ) can be determined from
either of the following equations:
TJ = (PD × RθJA) + TA
or TJ = (PD × RθJT) + TT
where PD = IO × (VI – VO) and
RθJT = 6°C/W.
SI-3012KM
1 A, Low-Dropout,
1.28~15 V Regulator
www.allegromicro.com
Linear
Regulators
7
Dimensions in Millimeters
Recommended Land Pattern
Terminal Finish: Pure Sn, 2nd level interconnect category (e3)
Product Weight: Approx. 0.33 g
3000 pieces per reel.
Tab Temperature
(TT) Measured Here
SI-3012KM
1 A, Low-Dropout,
1.28~15 V Regulator
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036
Linear
Regulators
8
Tape and Reel Dimensions in Millimeters
W1: 16.4 +2/-0 mm
W2: 22.4 mm Max.
W3: 16.4 +3/-0.5 mm
SI-3012KM
1 A, Low-Dropout,
1.28~15 V Regulator
www.allegromicro.com
Linear
Regulators
9
The products described herein are manufactured in Japan by Sanken
Electric Co., Ltd. for sale by Allegro MicroSystems, Inc.
Sanken and Allegro reserve the right to make, from time to time, such
departures from the detail specifications as may be required to permit
improvements in the performance, reliability, or manufacturability of its
products. Therefore, the user is cautioned to verify that the information
in this publication is current before placing any order.
When using the pr oducts described her ein, the applicability and
suitability of such pr oducts for the intended purpose shall be r eviewed at
the users responsibility .
Although Sanken undertakes to enhance the quality and r eliability of
its pr oducts, the occurr ence of failur e and defect of semiconductor
pr oducts at a certain rate is inevitable.
Users of Sanken pr oducts ar e r equested to take, at their own risk,
pr eventative measur es including safety design of the equipment or
systems against any possible injury , death, fir es or damages to society
due to device failure or malfunction.
Sanken pr oducts listed in this publication are designed and intended
for use as components in general-purpose electr onic equipment or
apparatus (home appliances, office equipment, telecommunication
equipment, measuring equipment, etc.). Their use in any application
r equiring radiation har dness assurance (e.g., aerospace equipment) is
not supported.
When considering the use of Sanken pr oducts in applications wher e
higher r eliability is r equired (transportation equipment and its contr ol
systems or equipment, fir e- or burglar-alarm systems, various safety
devices, etc.), contact a company sales r epresentative to discuss and
obtain written confirmation of your specifications.
The use of Sanken pr oducts without the written consent of Sanken in
applications wher e extremely high r eliability is requir ed (aer ospace
equipment, nuclear power-contr ol stations, life-support systems, etc.) is
strictly pr ohibited.
The information included herein is believed to be accurate and
reliable. Application and operation examples described in this publica-
tion are given for reference only and Sanken and Allegro assume no
responsibility for any infringement of industrial property rights,
intellectual property rights, or any other rights of Sanken or Allegro or
any third party that may result from its use.
EI16EI