WT431LT1
PROGRAMMABLE PRECISION REFERENCE
P b
Lead(Pb)-Free
Features:
* Programmagle output voltage to 36V.
* Low dynamic output impedance 0.2Ω.
* Sink current capability of 1 to 100mA.
* Equivalent full-range temperature coefficient of 50ppm/°C
typical for operation over full rated operating temperature range.
1
2
3
SOT-23
Description:
* The WT431 is a three-terminal adjustable regulator
with a guaranteed thermal stability over applicable
temperature ranges. The output voltage may be set to any
value between Vref(approximately 2.5) and 36V with two
external resistors. It provides very wide applications,
including shunt regulator, series regulator, switching
regulator, voltage reference and others.
SOT-23 Outline Dimensions
A
Unit:mm
TOP VIEW
B
C
E
G
H
D
K
J
L
M
Dim
A
B
C
D
E
G
H
J
K
L
M
Min
0.35
1.19
2.10
0.85
0.46
1.70
2.70
0.01
0.89
0.30
0.076
Max
0.51
1.40
3.00
1.05
1.00
2.10
3.10
0.13
1.10
0.61
0.25
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WT431LT1
BLOCK DIAGRAM
CATHODE
REF
+
-
V
REF
ANODE
PIN ASSIGNMENT
WT431R
3
WT431L
3
1
2
1
2
P
IN
1 = REF
P
IN
2 = Cathode
P
IN
3 = Anode
P
IN
1 = Cathode
P
IN
2 = REF
P
IN
3 = Anode
Ordering information
Ordering Number
WT431RA
WT431RB
WT431LA
WT431LB
Rank
0.5%
1%
0.5%
1%
Shipping
3000 Units / Tape & Reel
3000 Units / Tape & Reel
3000 Units / Tape & Reel
3000 Units / Tape & Reel
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WT431LT1
ABSOLUTE MAXIMUM RATINGS
(Operating temperature range applies unless otherwise specified)
PARAMETER
Cathode Voltage
Cathode Current Range(Continuous)
Reference Input Current Range
Operating Junction Temperature
Operating Ambient Temperature
Storage Temperature
SYMBOL
V
KA
VALUE
36
-100 ~ +150
-0.05 ~ +10
150
0~70
-65 ~ +150
UNIT
V
I
KA
I
ref
T
j
T
opr
T
stg
mA
mA
°C
°C
°C
RECOMMENDED OPERATING CONDITIONS
PARAMETER
Cathode Voltage
Cathode Current
SYMBOL
V
KA
I
KA
Min
V
REF
1
Typ
-
-
Max
36
100
UNIT
V
mA
ELECTRICAL CHARACTERISTICS
(T
A
=25˚C unless otherwise specified)
PARAMETER
Reference Input Voltage
Deviation of reference Input Voltage
Over temperature
SYMBOL
V
ref
ΔV
ref
/ΔT
TEST CONDITIONS
V
KA
=V
REF
, I
KA
=10mA
V
KA
=V
REF
, I
KA
=10mA
T
MIN
<=T
A
<=T
MAX
Min
-
-
-
-
-
-
-
-
Typ
2.50
4.5
-1.0
-0.5
1.5
0.4
0.45
0.05
0.15
Max
-
17
-2.7
-2.0
4
1.2
1.0
1.0
0.5
UNIT
V
mV
mV/V
µA
µA
mA
µA
Ω
Ratio of Change in Reference Input
ΔV
KA
=10V~V
REF
ΔV
ref
/ΔV
KA
I
KA
=10mA
Voltage to the change in Cathode Voltage
ΔV
KA
=36V~10V
Reference Input Current
Deviation of reference Input Current
Over Full temperature range
Minimum Cathode current for Regulation
Off-State Cathode current
Dynamic Impedance
I
ref
ΔI
ref
/ΔT
I
KA(min)
I
KA(OFF)
Z
KA
I
KA
=10mA, R1=10kΩ
I
KA
=10mA, R1=10kΩ
T
A
=full temperature
V
KA
=V
REF
V
KA
=36V, V
REF
=0
V
KA
=V
REF
=0, I
KA
=1 to 100mA
<=
∞
∞
CLASSIFICATION OF V
ref
AND & MARKING
PARAMETER
WT431RA
WT431RB
WT431LA
WT431LB
Rank
0.5%
1%
0.5%
1%
Range(V)
2.487~2.512
2.475~2.525
2.487~2.512
2.475~2.525
Marking
RA
RB
LA
LB
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WT431LT1
TYPICAL PERFORMANCE CHARACTERISTICS
1
1
T
A
C
RE
T
A
C
RE
A
A
C
4
C
1
1
1
3
1
1
3
C
C
C
I
A
C
Fig 1 Cathode Current Vs Cathode Voltage
C
C
C
T
C
IN
I
1
1
T
A
1
C
A
4
3
I
C
3
3
4
R
I
1
1
1
3
3
4
1
3
4
C
T
3C
C
R
I
4
R
1
T
I
A
1
1
C
A
1
A
4
3
T
I
A
1
C
A
I
1
1
1
1
A
3
4
1
1
1
1
1
1
1
3
1
4
1
1
1
D
I
A
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WT431LT1
WT431 LINEAR INTEGRATED CIRCUIT
TE T CIRCUIT
IN UT
I
A
A
IN UT
I
R1
I
RE
R
RE
A
A
IN UT
I
A
A
WT431
WT431
WT431
RE
A
RE
1 R1 R
I
RE
R1
7T
C
A
RE
8T
C
A
RE
9T
C
I
A
A
LICATI N CIRCUIT
IN
UT
R1
R1
WT7805
R1
C
N
RE
RE
RE
R
WT431
WT431
R
R
WT431
1 R1 R
RE
1 R1 R
RE
1 R1 R
RE
1
R
11
T
C
R
T
1
R
I
I
R
RCL
R
WT431
WT431
I
RE
R
I
RE
RCL
13 C
14 C
L
C
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