Rev. 10/25/00
SPX3431
Micropower 2.5V Precision
Adjustable
Shunt Regulator
FEATURES APPLICATIONS
Voltage Tolerance ..................................0.5% & 1.0%
Battery Operating Equipment
Wide Operating Current .................... 1mA to 100mA
Adjustable Supplies
Extended Temperature Range .......................... 105C
Switching Power Supplies
Low Temperature Coefficient ........................30 ppm/C
Error Amplifiers
Offered in SOT-23, TO-92 & SOT 89
Single Supply Amplifier
Low Output Noise
Monitors / VCR / TV
Personal Computers
PRODUCT DESCRIPTION
The SPX3431 is a 3-terminal Adjustable Shunt Voltage Regulator providing a highly accurate 0.5% bandgap reference. SPX3431 acts
as an open-loop error amplifier with a 2.5V temperature compensation reference. The SPX3431 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. SPX3431 tolerance of 0.5% is proven to be sufficient to overcome all the other errors in the
system to virtually eliminate the need for trimming in the power supply manufactures assembly line and contribute a big Cost
Savings.
In the standard shunt configuration, the combination of low temperature coefficient (T.C.), sharp turn-on characteristics, low output
impedance and programmable output voltage make this precision reference an excellent error amplifier.
The SPX3431 is a direct replacement for the SPX431 and TL431 in low voltage, low current applications. SPX3431 is also available
in SOT-89 and TO-92.
SOT-89
Marking &
pinout for all
devices
SOT-23
Marking & pinout for
the 0.5% device
SOT-23
Marking & pinout for
the 1% device
Top View
REF
CATHODE
ANODE
Top View
REF
CATHODE
ANODE
Top View
SPX3431
1
CATHODE
2
ANODE
3
REF
REF
Top View
1
3
2
CATHODE
ANODE
TO-92 (N)
SPX3431
SPX3432
PIN CONNECTIONS
Rev. 10/25/00
SPX3431
ABSOLUTE MAXIMUM RATINGS
Parameter Symbol
Rating
Units
Cathode-Anode Reverse Breakdown
V
KA
18 V
Anode-Cathode Forward Current
I
AK
1 A
Operating Cathode Current
I
KA
100 mA
Reference Input Current
I
REF
1 mA
Continuous Power Dissipation at 25
C
SOT-23
P
D
300
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 RESISTANCES
Parameter Symbol
Rating
Unit
Package
0
JA
0
JC
Typical
Derating
Cathode Voltage
V
KA
V
REF
to 18
V
SOT-23
575
C/W 150 C/W
1.7 mW/
C
Cathode Current
1
K
10
mA
SOT-89
575
C/W 80 C/W
9.1 mW/
C
TO-92
575
C/W 80 C/W
6.3 mW/
C
2.5V
+
-
REFERENCE
(R)
CATHODE (K)
ANODE (A)
Rev. 10/25/00
SPX3431
ELECTRICAL CHARACTERISTICS
are guaranteed over full junction temperature range (0
C to 105C). Ambient
temperature must be derated based on power dissipation and package thermal characteristics. The conditions are: V
KA
= V
REF
and
I
K
= 10mA, unless otherwise specified.
SPX3431A
SPX3431
Parameter
Symbol
Test
Condition Min Typ Max Min Typ Max Unit Circuit
Reference Voltage
V
REF
T
A
= 25
C
2.490 2.503 2.515 2.475 2.500 2.525 V
1
Over
Temp. 2.480 2.530
2.450 2.550 V
1
V
REF
with Temp*
TC
0.07 0.20 0.07 0.02 mV/C
1
Ratio of Change in V
REF
V
REF
V
REF
to 10 V
-2.7
-1.01
-2.7
-1.01
to Cathode Voltage
V
K
10 V 10 18 V
-2
-0.4
0.3
-2
-0.4
0.3
Reference Input Current
I
REF
0.7 4
0.7 4 A
2
I
REF
Temp Deviation
I
REF
0.4 1.2 0.4 1.2 A
2
Min I
K
for Regulation
I
K (MIN)
V
REF
= 0V
V
KA
= 18V
0.4 1 0.4 1 mA 1
Off State Leakage
I
K (OFF)
0.04 500
0.04 500 nA
3
Dynamic Output
Impedance
Z
KA
f < 1 kHz I
K
=
1 to 100mA
0.15 0.5 0.15 0.5
1
Calculating Average Temperature Coefficient (TC)
MV/V
2
0
0.019 mV/C
V
REF
0
0
0
ppm
mV
%
-10
-5
0.2
2000
Temperature (C)
0.001 %/C
7.6 ppm/C
15
30
45
60
75
90 105
TC in mV/C =
V
REF
(mV)
T
A
TC in %/C =
V
REF
at 25C
T
A
V
REF
)
)
x 100
TC in ppm/C =
V
REF
at 25C
T
A
V
REF
)
)
x 10
6
Rev. 10/25/00
SPX3431
Test Circuits
I
K
I
REF
V
IN
V
KA
= V
REF
V
IN
V
KA
I
K
R
1
R
2
(V
REF
)
Figure 1b. Test Circuit 2
Figure 1a. Test Circuit 1
V
IN
V
KA
I
K (OFF)
Figure 1c. Test Circuit 3
Rev. 10/25/00
SPX3431
ORDERING INFORMATION
Ordering No. Precision Output Accuracy
Packages
SPX3431M
1%
2.5V
3 Lead SOT-23
SPX3431AM
0.5%
2.5V
3 Lead SOT-23
SPX3431M1
1%
2.5V
3 Lead SOT-89
SPX3431AM1
0.5%
2.5V
3 Lead SOT-89
SPX3431N
1%
2.5V
3 Lead TO-92
SPX3431AN
0.5%
2.5V
3 Lead TO-92
SIGNAL PROCESSING EXCELLENCE
Sipex Corporation
Headquarters and Main Offices:
22 Linnell Circle
Billerica, MA 01821
TEL: (978) 667-8700
FAX: (978) 670-9001
e-mail: sales@sipex.com
233 South Hillview Drive
Milpitas, CA 95035
TEL: (408) 935-7600
FAX: (408) 934-7500
Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the application or use of any product or circuit described
hereing; neither does it convey any license under its patent rights nor the rights of others.
Corporation
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