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SI-3010LLSL
1.5 A, Ultra-Low-Dropout, 1~3.3 V Regulator
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-3010LLSL voltage regulator
offers the reduced dropout voltage and low quiescent current essential
for improved ef
fi
ciency. This device delivers a regulated output at up to
1.5 A. Integrated thermal and overcurrent protection enhance overall
system reliability.
An npn pass element provides a dropout voltage of less than 300
mV at 1 A of load current. Regulator accuracy and excellent tempera-
ture characteristics are provided by a bandgap reference. Low output
voltages eliminate the need for expensive PWM buck converters. The
low dropout voltage permits more efficient regulation before output
regulation is lost. 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. An LS-TTL/CMOS-
compatible input gives the designer complete control over power up,
standby, or power down.
This devices is supplied in a fully molded 8-lead miniature surface-
mount package (tape and reel) with enhanced power-dissipating qualities.
It is rated for continuous operation between -30°C and +100°C.
FEATURES
■
1.5 A Output Current
■
Adjustable 1 ~ 3.3 V Output Voltage
■
0.3 V Maximum Dropout Voltage at I
O
= 1 A
■
Fast Transient Response
■
1
μA
Maximum Standby Current
■
Remote Voltage Sensing
■
Foldback Current Limiting
■
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
Always order by complete part number, e.g.,
SI-3010LLSL-TL
,
where “-TL” indicates tape and reel..
Data Sheet
27468.44b
OUT
ADJ
BIAS
ENABLE
1
8
IN
IN
GND
GND
2
7
VR
3
V
S
6
4
5
Dwg. PK-012-1
ABSOLUTE MAXIMUM RATINGS
Input Voltage, V
I
. . . . . . . . . . . . . .
10 V
Output Current, I
O
. . . . . . . . . . . .
1.5 A*
Bias Voltage, V
S
. . . . . . . . . . . . . .
10 V
Enable Input Voltage, V
E
. . . . . . . . . .
V
I
Junction Temperature, T
J
. . . . .
+125°C
Storage Temperature Range,
T
S
. . . . . . . . . . . . .
-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.
Sanken Power Devices
from Allegro MicroSystems
SI-3010LLSL
1.5 A, Ultra-Low-Dropout,
1~3.3 V Regulator
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FUNCTIONAL BLOCK DIAGRAM
Allowable Package Power Dissipation
Recommended Operating Conditions
Min
DC Input Voltage
1.4
Adjustable Output Volt. Range 1.1
DC Output Current
0
DC Bias Voltage
Operating Junction Temp.
3.3
-20
Max
3.6
3.3
1.5
5.5
+100
Units
V
V
A
V
°C
For the availability of parts meeting -40°C requirements,
contact Allegro’s Sales Representative.
Leads 7 and 8 are soldered to
the PCB copper area and
provide heat sinking of the pass
transistor.
This data sheet is based on Sanken data sheet SSJ-02412.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036
Copyright © 2004, 2005 Allegro MicroSystems, Inc.
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Re Lin
gu ea
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SI-3010LLSL
1.5 A, Ultra-Low-Dropout,
1~3.3 V Regulator
otherwise noted).
ELECTRICAL CHARACTERISTICS
at T
A
= +25°C, V
I
= 1.8 V, V
O
= 1.5 V adjusted, V
S
= 3.3 V, V
E
= 2 V (unless
Limits
Characteristic
Output Volt. Temp. Coeff.
Internal Reference Voltage
Output Short-Circuit Current
Line Regulation
Load Regulation
Dropout Voltage
Ground Terminal Current
Enable Input Voltage
Enable Input Current
Ripple Rejection Ratio
Thermal Shutdown
Symbol
Test Conditions
0°C
≤
T
J
≤
100°C
I
O
= 10 mA
see note
V
I
= 1.7 ~ 2.5 V, I
O
= 10 mA
V
I
= 1.8 V, I
O
= 0 A ~ 1.0 A
I
O
= 1.0 A
I
O
= 0 mA, V
E
= 2.0 V
V
E
= 0 V
V
EH
V
EL
I
EH
I
EL
PSRR
T
J
Output ON
Output OFF
V
E
= 2.7 V
V
E
= 0 V
100 Hz
≤
f
≤
120 Hz
Min.
—
0.980
1.6
—
—
—
—
—
2.0
—
—
—
—
135
Typ.
±0.2
—
—
—
—
500
—
—
—
—
—
60
152
Max.
—
—
10
30
0.3
800
1.0
—
0.8
50
10
—
—
Units
mV/°C
V
A
mV
mV
V
μA
μA
V
V
μA
μA
dB
°C
a
VO
V
ref
I
OM
ΔV
O(ΔVI)
ΔV
O(ΔIO)
V
Imin
- V
O
I
GND
1.000 1.020
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)
.
www.allegromicro.com
3
SI-3010LLSL
1.5 A, Ultra-Low-Dropout,
1~3.3 V Regulator
r
ea tors
in la
L u
eg
R
(V
O
= 1.5 V adjusted, V
I
= 1.8 V, V
S
= 3.3 V, T
A
= 25°C)
Dropout Voltage
Low-Voltage Behavior
Overcurrent Protection
TYPICAL CHARACTERISTICS
Input Line Regulation
Bias Line Regulation
Load Regulation
ENABLE Control Voltage
4
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036
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Input Capacitor
(C
I
, 0.1 µF to 10 µF). This is necessary
either when the input line includes inductance or when the
wiring is long.
Output Capacitor
(C
O
,
≥
47 µF). This device is de-
signed for use with a very low ESR output capacitor such
as a ceramic capacitor. Output oscillation may occur with
an ESR greater than 500 mΩ.
Output Voltage Adjustable Resistors
(R1 and R2).
The output voltage can be adjusted by R1 and R2. 10 kΩ
or 11 kΩ for R2 is recommended.
R1 = (V
O
– V
ref
)/(V
ref
/R2)
Soft-Start Capacitor
(C
SS
). This capacitor between V
O
and ADJ will set up starting time.
ENABLE Input.
The ENABLE (control) input features
an internal pull-down resistor. Leaving this input open
causes the output to turn off.
Determination of DC Input Voltage.
The minimum
input voltage V
I
(min) should be higher than the sum of the
fixed output voltage and the maximum rated dropout
voltage.
Overcurrent Protection.
The SI-3000LLSL 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.
SI-3010LLSL
1.5 A, Ultra-Low-Dropout,
1~3.3 V Regulator
APPLICATIONS INFORMATION
Heat Radiation and Reliability.
The reliability of the
device is directly related to the junction temperature (T
J
) in
its operation. Accordingly, careful consideration should be
given to heat dissipation.
The inner frame on which the pass transistor is mounted is
connected to terminals 7 and 8. Therefore, it is very
effective for heat radiation to enlarge the copper area that is
connected to these terminals. The graph illustrates the
effect of the copper area on the junction-to-ambient thermal
resistance (R
θJA
).
The junction temperature (T
J
) can be determined from
either of the following equations:
T
J
= (P
D
× R
θJA
) + T
A
or
T
J
= (P
D
× R
θJL
) + T
L
where P
D
= I
O
× (V
I
– V
O
),
T
L
is the temperature of lead 8, and
R
θJL
= 36°C/W.
Parallel Operation.
Parallel operation to increase load
current is not permitted.
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