SC431 Datasheet

SC431
Adjustable Shunt Regulator
POWER MANAGEMENT
Description
Features
The SC431 is a three terminal adjustable shunt
regulator with thermal stability guaranteed over
temperature. The output voltage can be adjusted to any
value from 2.5V (V REF ) to 30V with two external
resistors. The SC431 has a typical dynamic output
impedance of 0.25Ω. Active output circuitry provides a
very sharp turn on characteristic, making the SC431 an
excellent replacement for zener diodes.
‹
‹
‹
‹
‹
‹
The SC431 shunt regulator is available with four
voltage tolerances (0.5%, 1.0% and 2.0% over TA = -40°C
to +85°C and 0.5% over TA = -40°C to +125°C) and two
package options (SOT-23-3 and SO-8). This
allows the designer the opportunity to select the
optimum combination of cost and performance for their
application.
Wide operating current range 130µA to 150mA
Low dynamic output impedance 0.25 Ω typ.
Trimmed bandgap design + 0.5%
Alternate for TL1431, TL431, LM431 & AS431
Industrial temperature range
Available in SOT-23-3 and SO-8 packages.
Also available in Lead-free, fully WEEE and RoHS
compliant.
Applications
‹
‹
‹
‹
‹
‹
Linear Regulators
Adjustable Supplies
Switching Power Supplies
Battery Operated Computers
Instrumentation
Computer Disk Drives
Typical Application Circuit(1)(2)
Notes:
1) Set VOUT according to the following equation:
R1 

VOUT = VREF 1 +
 + IREF R1
 R2 
2) Choose the value for R as follows:
• The maximum limit for R should be such that the
cathode current, I Z , is greater than the minimum
operating current (130µA) at VIN(MIN).
• The minimum limit for R should be such that IZ does
not exceed 150mA under all load conditions, and the
instantaneous turn-on value for I Z does not exceed
200mA. Both of the following conditions must be met:
Rmin ≥
R min ≥
VIN(max)
200mA
(to limit instantaneous turn-on IZ)
VIN(max) − VOUT
IOUT (min) + 150mA (to limit IZ under normal
operating conditions)
Revision: April 23, 2008
1
www.semtech.com
SC431
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
Cathode Voltage
VZ
31
V
Continous Cathode Current
IZ
150
mA
Reference Input Current
IREF
10
mA
Power Dissipation at TA = 25°C
SOT-23-3
SO-8
PD
0.37
0.78
W
Thermal Resistance
SOT-23-3
SO-8
θJ A
336
163
°C/W
Operating Ambient Temperature Range
SC431Cx-.5, SC431Cx-1, SC431Cx-2
SC431CxQ
TA
-40 to +85
-40 to +125
°C
Operating Junction Temperature Range
TJ
-40 to +150
°C
Storage Temperature Range
TSTG
-65 to +150
°C
Lead Temperature (Soldering) 10 seconds
TLEAD
300
°C
ESD Rating (Human Body Model)
V ESD
2
kV
Electrical Characteristics
Unless specified:TA = 25°C. Values in bold apply over full operating ambient temperature range.
SC431Cx-.5,
S C 431C xQ
Parameter
SC431Cx-1
Symbol
Condition
Min
Typ
Max
Min
Typ
Max
Units
Reference Voltage
VREF
VZ = VREF, IZ = 10mA(1)
2.482
2.495
2.507
2.470
2.495
2.520
V
VREF Temp Deviation
V D EV
VZ = VREF, IZ = 10mA(1)
8
17
8
25
mV
Ratio of Change in
∆VREF
∆VZ
IZ = 10mA, ∆VZ = 10V to VREF
-0.5
-2.7
-0.5
-2.7
mV/V
IZ = 10mA, ∆VZ =30V to 10V
-1.0
-2.0
-1.0
-2.0
VREF to Change in VZ
Reference Input
Current
IREF
R1 = 10kΩ, R2 = ∞,
IZ = 10mA(2)
0.5
4
0.5
4
µA
IREF Temperature
Deviation
IREF(DEV)
R1 = 10kΩ, R2 = ∞,
IZ =10mA(2)
0.4
1.2
0.4
1.2
µA
IZ (OFF)
VREF = 0V, VZ =30V(3)
0.04
0.50
0.04
0.50
µA
rZ
f < 1kHz, VZ = VREF
IZ = 130µA to 100mA(1)
0.25
0.50
0.25
0.50
Ω
IZ (MIN)
VZ = VREF(1)
130
µA
Off-State Cathode
Current
Dynamic Output
Impedance
Minimum Operating
Current
 2008 Semtech Corp.
130
2
www.semtech.com
SC431
POWER MANAGEMENT
Electrical Characteristics (Cont.)
Unless specified:TA = 25°C. Values in bold apply over full operating ambient temperature range.
SC431Cx-2
Parameter
Symbol
Condition
Min
Typ
Max
Units
Reference Voltage
VREF
VZ = VREF, IZ = 10mA(1)
2.445
2.495
2.545
V
VREF Temp Deviation
V D EV
VZ = VREF, IZ = 10mA(1)
15
30
mV
∆VREF
∆VZ
IZ = 10mA, ∆VZ = 10V to VREF
-0.5
-2.7
mV/V
IZ = 10mA, ∆VZ =30V to 10V
-1.0
-2.0
IREF
R1 = 10kΩ, R2 = ∞, IZ = 10mA(2)
0.5
4
µA
IREF Temperature Deviation
IREF(DEV)
R1 = 10kΩ, R2 = ∞, IZ =10mA(2)
0.4
1.2
µA
Off-State Cathode Current
IZ (OFF)
VREF = 0V, VZ =30V(3)
0.04
0.50
µA
Dynamic Output Impedance
rZ
f < 1kHz, VZ = VREF, IZ = 130µA to 100mA(1)
0.25
0.50
Ω
Minimum Operating Current
IZ (MIN)
VZ = VREF(1)
130
µA
Ratio of Change in VREF to
Change in VZ
Reference Input Current
Notes:
(1) See Test Circuit 1 below.
(2) See Test Circuit 2 below.
(3) See Test Circuit 3 below.
Test Circuits
Test Circuit 2
VZ > VREF
Test Circuit 1
VZ = VREF
Test Circuit 3
Off-State
Recommended Operating Conditions
Cathode Voltage, VZ
Cathode Current, IZ
 2008 Semtech Corp.
Min
Max
Symbol
VREF
30
V
0.130
150
mA
3
www.semtech.com
SC431
POWER MANAGEMENT
Pin Configurations
SO-8 (Top View)
SOT-23-3 (Top View)
Block Diagram
Symbol
Ordering Information
Tolerance
0.5%
0.5%
1.0%
2.0%
-40°C to +85°C
-40°C to +125°C
-40°C to +85°C
-40°C to +85°C
SOT-23-3(1)
SC431CSK-.5 TR
SC431CSKQTR
SC431CSK-1.TR
SC431CSK-2.TR
SOT-23-3(1),(3)
SC431CSK-.5TRT
SC431CSKQTRT
SC431CSK-1TRT
SC431CSK-2TRT
SC431CS-.5 TR
SC431CSQTR
SC431CS-1.TR
SC431CS-2.TR
SC431CS-.5 TRT
SC431CSQTRT
SC431CS-1.TRT
SC431CS-2.TRT
Ambient Temperature Range
SO-8(2)
SO-8(2)(3)
Notes:
(1) Only available in tape and reel packaging. A reel contains 3000 devices.
(2) Only available in tape and reel packaging. A reel contains 2500 devices.
(3) “T” at end of part number indicates “lead free”. This product is fully WEEE and RoHS compliant.
 2008 Semtech Corp.
4
www.semtech.com
SC431
POWER MANAGEMENT
Marking Information
SOT-23-3 (Top View)
SO-8 (Top View)
SC
431CS
yyww
431
431
SO-8 (Bottom View)
xxxxx
yyww = Datecode (Example: 0008)
xxxxx = Semtech Lot # (Example: 00101)
 2008 Semtech Corp.
5
www.semtech.com
SC431
POWER MANAGEMENT
Typical Characteristics
300
Cathode Current vs.
Cathode Current vs.
Cathode Voltage
Cathode Voltage
150
VZ = VREF
VZ = VREF
o
o
TA = 25 C
200
50
IZ (mA)
100
IZ ( A)
TA = 25 C
100
0
0
-100
-50
-200
-100
-300
-150
-2
-1
0
1
2
3
-2
-1
0
VZ (V)
2.515
2
Reference Voltage vs.
Reference Input Current vs.
Junction Temperature
Junction Temperature
100
VZ = VREF
IZ = 10mA
2.510
1
3
VZ (V)
IZ = 10mA
R1 = 10kΩ
R2 = ∞
80
IREF (nA)
VREF (V)
2.505
2.500
60
40
2.495
20
2.490
2.485
0
-50
-25
0
25
50
75
100
125
150
-50
-25
0
25
TJ (°C)
50
75
100
Ratio of Delta Reference Voltage to Delta Cathode
Off-State Cathode Current
Voltage vs. Junction Temperature
vs. Junction Temperature
150
100
IZ = 10mA
∆VZ = 3V to 30V
0.4
10
0.3
1
125
150
VZ = 30V
VREF = 0V
IZ(off)
VREF/ VZ (-mV/V)
0.5
125
TJ (°C)
0.2
0.1
0.1
0.01
0.001
0
-50
-25
0
25
50
75
100
125
-50
150
 2008 Semtech Corp.
-25
0
25
50
75
100
TJ (°C)
TJ (°C)
6
www.semtech.com
SC431
POWER MANAGEMENT
Typical Characteristics (Cont.)
Test Circuit - Small-Signal Gain and Phase
Small-Signal Gain and Phase Shift
vs. Frequency
IZ = 10mA
TA = 25°C
AV (dB)
70
-180
-225
60
-270
50
-315
40
-360
30
-405
20
-450
10
-495
0
-540
-10
-585
-20
Phase Shift (deg)
80
-630
1.0E+02
1.0E+03
1.0E+04
1.0E+05
1.0E+06
f (Hz)
Reference Impedance
vs. Frequency
100
IZ = 10mA
TA = 25°C
rZ ( )
10
1
0.1
0.01
1.0E+03
1.0E+04
1.0E+05
1.0E+06
1.0E+07
f (Hz)
Stability Boundary Condition For Shunt Regulation
Test Circuit - Stability
vs. Cathode Current and Load Capacitance
 2008 Semtech Corp.
7
www.semtech.com
SC431
POWER MANAGEMENT
Outline Drawing - SOT-23-3
D
A
DIM
e1
3
A
A1
A2
b
c
D
E
E1
e
e1
L
L1
N
0
aaa
bbb
B
E
E1
1
2
bxN
bbb
e
.035
.000
.035
.012
.003
.110
.082
.047
.015
0°
-
1.12
0.89
0.01
0.10
0.88 0.95 1.02
0.30
0.51
0.08
0.18
2.80 2.90 3.04
2.10 2.37 2.64
1.20 1.30 1.40
1.90 BSC
0.95 BSC
0.40 0.50 0.60
(0.55)
3
0°
8°
0.10
0.20
.044
.004
.040
.020
.007
.120
.104
.055
.037
.114
.093
.051
.075
.037
.020
.022
3
-
.024
8°
.004
.008
C A B
A2
A
DIMENSIONS
INCHES
MILLIMETERS
MIN NOM MAX MIN NOM MAX
aaa C
3X
SEATING PLANE
A1
C
H
GAUGE
PLANE
SEATING
PLANE
C
0
0.25
L
L1
SEE DETAIL A
SIDE VIEW
c
DETAIL A
NOTES:
1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).
2. DATUMS -A- AND -B- TO BE DETERMINED AT DATUM PLANE
-H-
3. DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS
OR GATE BURRS.
Land Pattern - SOT-23-3
X
Y
DIM
Z
G
C
Y
C
E
E1
G
X
Y
Z
DIMENSIONS
INCHES
MILLIMETERS
(.087)
.037
.075
.031
.039
.055
.141
(2.20)
0.95
1.90
0.80
1.00
1.40
3.60
E
E1
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.
 2008 Semtech Corp.
8
www.semtech.com
SC431
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
INCHES
MILLIMETERS
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
A
DETAIL
SIDE VIEW
01
NOTES:
1.
CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).
2.
DATUMS -A- AND -B- TO BE DETERMINED AT DATUM PLANE -H-
3.
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
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.
Contact Information
Semtech Corporation
Power Management Products Division
200 Flynn Road, Camarillo, CA 93012
Phone: (805)498-2111 FAX (805)498-3804
 2008 Semtech Corp.
9
www.semtech.com