SEMTECH SC1541

SC1541
1.0A Low Dropout Voltage
Regulator with Enable
POWER MANAGEMENT
Description
Features
The SC1541 is a high performance low dropout positive
voltage regulator designed for use in applications where
power management is critical, such as battery powered
systems.
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Additionally, the SC1541 provides excellent regulation
over variations in line, load and temperature.
Outstanding features include low dropout performance
at rated current, fast transient response, internal
current limiting and thermal shutdown protection of the
output device. A very low quiescent current of 10µA in
shutdown mode reduces power dissipation.
Low dropout performance, 1.3V max
Full current rating over line and temperature
Fast transient response
+2% total output regulation over line, load
and temperature
10µA max. quiescent current in shutdown
Three fixed output voltages
Line regulation 0.2% max.
Load regulation 0.4% max.
SO-8 and TO-263 packages
Applications
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The SC1541 is available with three different voltage
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options as standard and two package options, SO-8 and
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5-lead TO-263.
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Low voltage microcontrollers
Switching power supply post-regulation
Instantly available circuits
Motherboards
Battery operated equipment
Typical Application Circuit
V IN
U1
SC1541
IN
OUT
EN
ENABLE SIGNAL
C1
10uF
Tantalum
V OUT
GND
C2
10uF min.
Tantalum
Notes:
(1) Input and output capacitors should be located close to the device.
(2) Connect all pins to PCB (SO-8 package) for optimal thermal characteristics.
(3) Increasing the output capacitor value will improve the overall transient response.
(4) The device is enabled when VEN = VIN, and shut down when EN is pulled to ground. EN should not be taken higher
than VIN. A CMOS signal referenced to VIN would be ideal for switching the SC1541 on and off.
Revision: November 25, 2009
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SC1541
POWER MANAGEMENT
Absolute Maximum Ratings
Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters
specified in the Electrical Characteristics section is not implied.
Parameter
Symbol
Maximum
Units
Maximum Input Pin Voltage
VIN, VEN
7
V
Power Dissipation
PD
Internally Limited
W
Thermal Resistance Junction to Case
SO-8
TO-263
θJ C
39
3
°C/W
Thermal Resistance Junction to Ambient
SO-8(1)
TO-263
θJ A
65
60
°C/W
Operating Junction Temperature Range
TJ
0 to 125
°C
Storage Temperature Range
TSTG
-65 to 150
°C
Lead Temperature (Soldering) 10 Sec
TLEAD
300
°C
Note:
(1) 1 inch square of 1/16” FR-4, double sided, 1 oz. minimum copper weight.
Electrical Characteristics
Unless otherwise specified: IO = 0mA to 1A, VEN = VIN, 1.8V Option: VIN = 3.2V to 7.0V, 2.5 Option: VIN = 3.9V to 7.0V,
3.3V Option: VIN = 4.7V to 7.0V. Values in bold apply over full operating temperature range.
Parameter
Output Voltage
Symbol
(1)
VOUT
VIN = 5V, IOUT = 0mA
Min
Typ
Max
Units
-1
VOUT
+1
%
-2
+2
Line Regulation(1)
REG(LINE)
IOUT = 10mA
0.035
0.2
%
Load Regulation(1)
REG(LOAD)
VIN = 5V
0.2
0.4
%
Dropout Voltage(1)(2)
VD
IOUT = 1A
1.10
1.30
V
Current Limit(1)
ICL
Quiescent Current
IQ
1.1
VIN = VEN = 5V
A
5
7
mA
10
VIN = 5V, VEN < 0.25V
6
8
µA
10
Enable Pin Control Voltage
Enable Pin Current
 2004 Semtech Corp.
V EN
IEN
Device OFF
0.25
0.45
V
Device ON
(VOUT + 0.5)
(VOUT + 0.8)
VEN = 0V, VIN = 5V (OFF)
0.1
1.0
VEN = VIN = 5V (ON)
15
25
2
µA
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SC1541
PRELIMINARY
POWER MANAGEMENT
Electrical Characteristics (Cont.)
Unless otherwise specified: IO = 0mA to 1A, VEN = VIN, 1.8V Option: VIN = 3.2V to 7.0V, 2.5 Option: VIN = 3.9V to 7.0V,
3.3V Option: VIN = 4.7V to 7.0V. Values in bold apply over full operating temperature range.
Parameter
Symbol
Min
Typ
Max
Units
Temperature Coefficient
TC
0.005
%/C
Temperature Stability
TS
0.5
%
RMS Output Noise(3)
VN
0.003
%VOUT
Ripple Rejection Ratio(4)
RA
72
dB
VIN = 5V
60
Notes:
(1) Low duty cycle pulse testing with Kelvin connections required.
(2) ∆VOUT, ∆VREF = 1%.
(3) Bandwidth of 10 Hz to 10kHz.
(4) 120Hz input ripple.
(5) This device is ESD sensitive. Use of standard ESD handling precautions is required.
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SC1541
POWER MANAGEMENT
Pin Configurations
Ordering Information
Device(1)(2)
SC1541CM-X.X.TR
SC1541CM-X.X.TRT(3)
SC1541CS-X.X.TR
SC1541CS-X.X.TRT(3)
TO-263-5
FUNCTION
1
EN
2
GND
3/TAB
OUT
4
IN
5
NC
TO-263-5
SO-8
Notes:
(1) Where X.X denotes voltage options. Available
voltages are: 1.8V, 2.5V and 3.3V. Contact factory for
additional voltage options.
(2) Only available in tape and reel packaging. A reel
contains 800 (TO-263-5) or 2500 (SO-8) devices.
(3) Halogen Free, and RoHS/WEEE compliant.
SO-8
PIN
P ackag e
Block Diagram
Pin Descriptions
Pin Name
SO-8 Pin #
TO-263-5 Pin #
EN
1
1
Active high enable for the regulator output. Connect to VIN if not being used.
GND
2
2
Ground pin. Bottom end of the internal feedback resistor chain.
NC
4
5
No connection.
IN
3
4
This is the input supply pin for the device.
OUT
5, 6, 7, 8
3/TAB
 2004 Semtech Corp.
Pin Function
This is the power output of the device. This pin is electrically connected to
the tab of the TO-263-5 package.
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SC1541
POWER MANAGEMENT
Outline Drawing - SO-8
A
D
e
N
DIM
E1 E
1
2
ccc C
2X N/2 TIPS
.053
.069
.004
.010
.049
.065
.012
.020
.007
.010
.189 .193 .197
.150 .154 .157
.236 BSC
.050 BSC
.010
.020
.016 .028 .041
(.041)
8
0°
8°
.004
.010
.008
A
A1
A2
b
c
D
E1
E
e
h
L
L1
N
01
aaa
bbb
ccc
2X E/2
e/2
B
D
DIMENSIONS
MILLIMETERS
INCHES
MIN NOM MAX MIN NOM MAX
aaa C
SEATING
PLANE
h
A2 A
C
A1
bxN
bbb
1.35
1.75
0.10
0.25
1.25
1.65
0.31
0.51
0.17
0.25
4.80 4.90 5.00
3.80 3.90 4.00
6.00 BSC
1.27 BSC
0.25
0.50
0.40 0.72 1.04
(1.04)
8
0°
8°
0.10
0.25
0.20
h
H
C A-B D
c
GAGE
PLANE
0.25
SEE DETAIL
L
(L1)
A
DETAIL
SIDE VIEW
01
A
NOTES:
1.
CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).
2. DATUMS -A- AND -B- TO BE DETERMINED AT DATUM PLANE -H3. DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS
OR GATE BURRS.
4. REFERENCE JEDEC STD MS-012, VARIATION AA.
Land Pattern - SO-8(1)
X
DIM
(C)
G
C
G
P
X
Y
Z
Z
Y
DIMENSIONS
INCHES
MILLIMETERS
(.205)
.118
.050
.024
.087
.291
(5.20)
3.00
1.27
0.60
2.20
7.40
P
NOTES:
1.
THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY.
CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR
COMPANY'S MANUFACTURING GUIDELINES ARE MET.
2. REFERENCE IPC-SM-782A, RLP NO. 300A.
Note:
(1) More copper area should be used to lower RTH(J-A) as needed.
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SC1541
POWER MANAGEMENT
Outline Drawing - TO-263-5
A
E
E/2
DIM
0
A
A1
b
c
c1
D
D1
E
E1
H
e
L
L1
N
0
01
aaa
L1
D
H
1 2 3 4 5
e
bXN
aaa
B A
DIMENSIONS
INCHES
MILLIMETERS
MIN NOM MAX MIN NOM MAX
.190
.010
.039
.029
.065
.380
.420
.625
.067 BSC
.070
.110
.066
5
15°
0°
8°
.010
.160
.000
.020
.015
.045
.326
.270
.380
.245
.575
4.06
4.83
0.00
0.25
0.51
0.99
0.38
0.74
1.14
1.65
8.28
9.65
6.86
9.65
10.67
6.22
14.61
15.88
1.70 BSC
1.78
2.79
1.68
5
15°
0°
8°
0.25
A
SEATING
PLANE
A1
B
c1
SIDE VIEW
SEE DETAIL
PLATED COPPER
HEAT SPREADER
A
D1
(L1)
c
E1
L
DETAIL
NOTES:
1.
A
01
CONTROLLING DIMENSIONS ARE IN INCHES (ANGLES IN DEGREES).
2. DIMENSIONS "D" AND "E" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS
OR GATE BURRS.
Land Pattern - TO-263-5(1)
H
DIM
K
Z
DIMENSIONS
INCHES
MILLIMETERS
G
H
K
P
X
Y
Z
.125
.420
.360
.067
.042
.140
.625
3.18
10.67
9.14
1.70
1.07
3.56
15.88
G
Y
P
X
NOTES:
1. CONTROLLING DIMENSIONS ARE IN INCHES (ANGLES IN DEGREES).
2. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY
CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR
COMPANY'S MANUFACTURING GUIDELINES ARE MET.
Note:
(1) More copper area should be used to lower RTH(J-A) as needed.
Contact Information
Semtech Corporation
Power Management Products Division
200 Flynn Road, Camarillo, CA 93012
Phone: (805)498-2111 FAX (805)498-3804
 2004 Semtech Corp.
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