Rev. 10/30/00
SPX431L
Low Voltage Precision
Adjustable Shunt Regulator
FEATURES
APPLICATIONS
Tight Tolerance.................................................. 0.5% @ 10mA
Battery Operating Equipment
Wide Operating Range..................................... 1mA to 100mA
Adjustable Supplies
Low Extended Temperature Range ....................0C to 105C
Switching Power Supplies
Low Temperature Coefficient .................................30 ppm/C
Error Amplifiers
Offered in TO-92, SOT-89, SOT-23-3 and SO-8
Single Supply Amplifier
Improved replacement in performance of AS431 & TL431
Monitors/ VCR/ TV
Low Cost Solution
Personal Computers
PRODUCT DESCRIPTION
The SPX431L is a 3-terminal Adjustable Shunt Voltage Regulator providing a highly accurate bandgap reference. SPX431L acts as an
open-loop error amplifier with a 2.5V temperature compensation reference. The SPX431L thermal stability, wide operating current
(100mA) and temperature range (0
C to 105C) makes it suitable for all variety of applications that are looking for a low cost solution
with high performance.
The output voltage may be adjusted to any value between V
REF
and 20V with 2 external resistors. The SPX431L is operating in full
industrial temperature range of 0C to 105C. The SPX431L is available in TO-92, SOT-89, SOT-23-3 and SO-8 packages.
2.5V
+
-
REFERENCE
(R)
CATHODE (K)
ANODE (A)
Bottom View
TO-92 (N)
1
3
2
N/C
CATHODE
ANODE
REF
Top View
2
1
3
4
8
7
6
5
SPX431L
8-Pin Surface Mount (S)
CATHODE
REF
ANODE
ANODE
ANODE
ANODE
N/C
SOT-23-3 (M)
3
2
Top View
SPX431L
Top View
SPX431L
SOT-89 (M1)
1
2
3
REF
ANODE
CATHODE
ANODE
CATHODE
N/C
1
PIN CONNECTIONS
Rev. 10/30/00
SPX431L
ABSOLUTE MAXIMUM RATINGS
Parameter Symbol
Rating
Units
Cathode-Anode Reverse Breakdown
V
KA
30 V
Anode-Cathode Forward Current
I
AK
1 A
Operating Cathode Current
I
KA
150 mA
Reference Input Current
I
REF
10 mA
Continuous Power Dissipation at 25
C
TO-92
SOT-23
SOIC-8
SOT-89
P
D
775
200
750
1000
mW
mW
mW
mW
Junction Temperature
T
J
150 C
Storage Temperature
T
STG
-65 to +150
C
Lead Temperature (Soldering 10 sec.)
T
L
300 C
Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause permanent damage to the device. This is a stress rating only and functional
operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect reliability.
RECOMMENDED CONDITIONS
TYPICAL THERMAL RESISTANCE
Parameter Symbol
Rating
Unit
Package
Type
JA
JC
Typical Derating
Cathode Voltage
V
KA
V
REF
to 20
V
TO-92
160
C/W 80C/W 6.3
mW/
C
Cathode Current
I
K
10
mA
SOT-23
575
C/W 150C/W 1.7
mW/
C
SOIC-8
175
C/W 45C/W 5.7
mW/
C
SOT-89
110
C/W 8C/W 9.1
mW/
C
ELECTRICAL CHARACTERISTICS
at 25C I
K
@ 10mA V
K
=V
REF
, unless otherwise specified.
Parameter
Symbol
Test Conditions
SPX431LA
SPX431L
SPX431LC
Unit
Min Typ Max Min Typ Max Min Typ Max
Reference
Voltage
V
REF
T
A
= 25
C TC = 1 2.490 2.503 2.515 2.470 2.495 2.520 2.445 2.495 2.545 V
Ratio of Change
in V
REF
to
Cathode Voltage
V
REF
V
K
V
REF
to 10V
10V to 20V TC =
2
-2.7
-2
-1.0
-0.4
0.3
-2.7
-2
-1.0
-0.4
0.3
-2.7
-2
-1.0
-0.4
0.3
mV/V
Reference Input
Current
I
REF
TC = 2
0.7
4
0.7
4
0.7
4
A
I
REF
Temp
Deviation
I
REF
Over Temp. TC =
2
0.4
1.2 0.4
1.2 0.4
1.2
A
Min I
K
for
Regulation
I
K(MIN)
TC = 1
0.4
1
0.4
1
0.4
1
mA
Off State Leakage
I
K(OFF)
V
REF
= 0V,
V
KA
= 20V TC =
3
0.04 1 0.04 1 0.04
1 A
Dynamic Output
Impedance
Z
KA
TC
=
1
0.15
0.5 0.15
0.5 0.15
0.5
TC = Test Circuit
Rev. 10/30/00
SPX431L
*CALCULATING AVERAGE TEMPERATURE COEFFICEINT (TC)
TEST CIRCUITS
I
K
I
REF
V
IN
V
KA
= V
REF
V
IN
V
KA
I
K
R
1
R
2
(V
REF
)
TEST CIRCUIT 2
TEST CIRCUIT 1
V
IN
V
KA
I
K (OFF)
TEST CIRCUIT 3
I
REF
1G-38
1G-39
1G-40
T
V
REF
0
15
30
45
60
75
90
105
-10
0.5
5000
0
0
ppm
%
mV
0
0.07 mV/C
0.003 %/C
27 ppm/C
TC in mV/C =
TC in mV/C =
V
REF
(mV)
T
A
T
A
V
REF
at 25C
V
REF
x 100
(
)
TC in ppm/C =
T
A
V
REF
at 25C
V
REF
x 10
6
(
)
Rev. 10/30/00
SPX431L
TYPICAL PERFORMANCE CURVES
Low Current Operating Characteristics
900
800
700
600
500
400
300
200
100
0
-100
-200
1.0
-1.0
2.0
0
3.0
V
KA
- Cathode Voltage (V)
I
K
- Cathode Current (
A)
V
KA
= V
REF
Temperature Range: - 0C to 105 C
105 C
25 C
-0 C
Figure 2
V
KA
- Cathode Voltage (V)
-2
-1
0
1
2
3
-100
-75
-50
-25
0
25
50
75
100
125
150
High Current Operating Characteristics
Figure 3
I
K
- Cathode Current (mA)
V
KA
= V
REF
Temperature Range: - 0C to 105 C
Off State Leakage
-60
-30
0
30
60
90
120
0.01
0.1
1
10
100
Figure 4
T
A
- Ambient Temperature ( C)
I
Z
off - Off State Cathode Current (nA)
V
KA
= 36V
V
REF
= 0V
T
A
- Ambient Temperature ( C)
Figure 5
Reference Voltage vs. Ambient Temperature
V
R
EF
- Reference Voltage (V)
-60
-30
0
30
60
90
120
2.45
2.46
2.47
2.48
2.49
2.50
2.51
2.52
2.53
V
KA
= V
REF
I
K
= 10 mA
V
REF
= 2.500 V at 25 C
Rev. 10/30/00
SPX431L
TYPICAL PERFORMANCE CURVES
T
A
- Ambient Temperature ( C)
Figure 6
Reference Input Current
I
R
EF
- Reference Input Current (
A)
-60
-30
0
30
60
90
120
0
R1 = 10 k
R2 =
I
K
= 10 mA
0.5
1.0
1.5
2.0
2.5
3.0
Figure 7
Reference Voltage Line Regulation
V
KA
- Cathode Voltage (V)
V
KA
- Cathode Voltage (V)
0
-10
-20
-30
-40
-50
0
3
6
9
12
15
18
21
24
27
105 C
75 C
30
25 C
0 C
Noise Voltage
Figure 8
f - Frequency (Hz)
Noise Voltage nV/
Hz
70
20
30
40
10
50
60
10
100
1 k
10 k
100 k
0
T
A
- Free Air Temperature
Figure 9
Low Frequency Dynamic Output Impedance
Z
K
A
- Dynamic Impedance (
)
-60
-30
0
30
60
90
120
0.0
V
KA
= V
REF
I
KA
= 1 to 100 mA
f < 1 kHz
0.025
0.050
0.075
0.100
0.125
0.150
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