Semiconductor
A431x
Programmable Voltage Reference
Description
The A431 series are 3-terminal precision shunt regulators that are programmable over a wide voltage range of
2.495V to 16V with ±0.5%, ±1.0% tolerance. The A431 series have a low dynamic impedance of 0.15Ω. These
features make the A431 series an excellent replacement for zener diodes in numerous applications circuits that
require a precision reference voltage.
Features
•
Programmable output voltage from 2.495V to 16V
•
Voltage reference tolerance : ±0.5%, ±1.0%
•
Cathode current capability of 1mA to 100mA
Ordering Information
Type NO.
A431x
Marking
A431□
□
: Grade => A:±1% , B:±0.5%
Package Code
TO-92
Outline Dimensions
( Unit : mm )
4.40~4.80
4.40~4.80
Symbol
0.50 Max.
13.50~14.50
Functional block diagram
Cathode(K)
Reference(R)
+
1.27 Typ.
1.27 Typ.
-
V
REF
=2.495V
1
3.40~3.60
2
3
Anode(A)
PIN Connections
1. Reference
2. Anode
3. Cathode
0.45 Max.
KSD-I0A003-000
1
A431x
Absolute maximum ratings
Characteristic
Cathode to Anode voltage
Cathode current
Reference input current
Power Dissipation
Junction Temperature
Operating temperature range
Storage temperature range
[Ta=25℃]
Symbol
V
KA
I
K
I
ref
P
D
T
J
T
opr
T
stg
Rating
18
150
10
625
150
-40 ~ +85
-55 ~ +150
Unit
V
mA
mA
mW
℃
℃
℃
Recommended operating conditions
Characteristic
Cathode to Anode voltage
Cathode current
Symbol
V
KA
I
K
Rating
Min.
V
ref
1
Max.
16
100
Unit
V
mA
Electrical Characteristics
(Ta=25
℃
, unless otherwise noted.)
Characteristic
Reference voltage (Fig.1)
Reference input voltage
deviation over temperature
(Fig.1, Note1,2)
Ratio of delta reference input
voltage to delta cathode
voltage (Fig.2)
Reference current (Fig.2)
Reference input current
deviation over temperature
(Fig.2, Note 1,2)
Minimum cathode current
for regulation
Off-state cathode current
(Fig.3)
Dynamic impedance
(Fig.1, Note3)
Symbol
V
ref
∆V
ref
∆V
ref
∆V
KA
I
ref
∆I
ref
I
K(MIN)
I
K(off)
Condition
V
KA
=V
ref
, I
K
=10mA
V
KA
=V
ref
, I
K
=10mA
@ 0˚C
≤
Ta
≤
70˚C
I
K
=10mA
V
ref
≤
V
KA
≤
16V
I
K
=10mA
R1=10KΩ, R2=∞
I
K
=10mA
R1=10KΩ, R2=∞
@ 0˚C
≤
Ta
≤
70˚C
V
KA
=V
ref
V
KA
=16V, V
ref
=0V
V
KA
=V
ref
, f
≤
1.0KHz
1.0mA
≤
I
K
≤
100mA
△V
ref
=V
ref(16V)
-V
ref
△V
KA
=V
KA(16V)
-V
ref
Min. Typ. Max.
A431B
A431A
2.482
2.470
-
-
-
-
-
-
2.495
2.508
2.520
30
-2.7
4.0
2.5
1.0
1000
Unit
V
7
-1.0
1.8
0.4
0.35
2.7
mV
mV/V
µΑ
µΑ
mΑ
nA
Z
KA
-
0.15
0.5
Ω
KSD-I0A003-000
2
A431x
Fig. 1 Test circuit for V
KA
=V
ref
Fig. 2 Test circuit for V
KA
>V
ref
Fig. 3 Test circuit for I
K(off)
Input
I
K
V
KA
Input
R1
R2
V
ref
I
K
I
ref
V
KA
Input
V
KA
I
K(off)
V
KA
= V
ref
× (1 +
R
1
) + I
ref
× R
1
R
2
Note.
1. Ambient temperature range: T
LOW
= 0℃, T
High
= 70℃
2. The deviation parameters
△V
ref
and
△I
ref
are defined as the difference between the maximum value and minimum value
obtained over the full operating ambient temperature range that applied.
∆V
ref
= V
ref
Max – V
ref
Min
∆Ta
= T
2
– T
1
Ambient Temperature
The average temperature coefficient of the reference input voltage,
α
V
ref
is defined as:
∆
V
ref
× 10
6
)
ppm
V
ref
(T
a
= 25
℃
)
α
V
ref
(
)=
℃
∆
T
a
(
α
V
ref
can be positive or negative depending on whether V
ref
Min or V
ref
Max occurs at the lower ambient temperature, refer to
Fig. 8
Example :
△V
ref
= 30mV and the slope is positive,
△V
ref
@ 25℃ = 2.495V
△Ta
= 70℃
0.03
) × 10
6
ppm
2.495
α
V
ref
(
)=
= 171ppm /
℃
℃
70
(
3. The dynamic impedance Z
KA
is defined as:
Ζ
KA
=
∆
V
KA
∆
I
K
When the device is operating with two external resistors, R1 and R2, (refer to Fig.2) the total dynamic impedance of the circuit
is given by:
Ζ
KA '
=
Ζ
KA
× (1 +
R
1
)
R
2
KSD-I0A003-000
3
A431x
Electrical Characteristics Curves
(Continue)
Fig.4 I
K
vs V
KA
(1)
150
ㅊ
Fig.5 I
K
vs V
KA
(2)
4.0
125
100
75
50
25
0
-25
-50
-75
Cathode current I
K
[mA]
Cathode current I
K
[mA]
V
KA
=V
ref
Ta=25˚C
V
KA
=V
ref,
Ta=25˚C
3.0
2.0
1.0
0.0
-0.2
-1
-
100
-2
-1
0
1
2
3
0
1
2
3
Cathode Voltage V
KA
[V]
Fig.6 I
K(off)
vs V
KA
Ratio of delta reference input voltage to delta
Cathode Voltage V
KA
[V]
Fig.7
ΔV
ref
/ΔV
KA
vs T
a
cathode voltag
ΔV
ref
/ΔV
KA
[mV/V]
0.0
-0.1
Off-state cathode current I
K(off)
[µA]
2.0
V
ref
=0V, Ta=25°C
1.5
-0.2
1.0
-0.3
I
0.5
0.0
0
4
8
12
16
20
-0.4
-0.5
-15
V
ref
≤
V
KA
≤
16V
I
K
=10mA
0
15
30
45
60
75
Cathode Voltage V
KA
[V]
Fig.8 V
ref
vs T
a
2.545
1000
Ambient Temperature T
a
[˚C]
Fig.9 P
D
vs T
a
Reference input voltage V
ref
[V]
V
KA
=V
ref ,
I
ref
=10mA
2.525
Power dissipation P
D
[mW]
V
ref(max)
V
ref(typ)
800
2.505
600
2.485
V
ref(min)
400
2.465
200
0
2.445
-15
0
15
30
45
60
75
0
25
50
75
100
125
150
Ambient Temperature T
a
[˚C]
Ambient Temperature T
a
[˚C]
KSD-I0A003-000
4
A431x
Electrical Characteristics Curves
Fig.10 Pulse Response
7
Input and output voltage – V
6
5
4
3
2
1
0
-1
0
2
4
Ta=25˚C
Input
B
220Ω
Output
A
Output
f=10KHz
50Ω
GND
Fig.11 Test circuit for Fig. 10
6
8
10
t – Time [μs ]
Fig.12 Pulse Response (Magnify A of Fig.10)
7
Fig.13 Pulse Response (Magnify B of Fig.10)
7
Input and output voltage – V
6
5
4
3
2
1
0
-1
0
Input and output voltage – V
Ta=25˚C
Input
6
5
4
3
2
1
0
-1
0
Ta=25˚C
Input
Output
Output
1
2
3
4
5
1
2
3
4
5
t – Time [μs ]
Fig.14 Stability Boundary Conditions
t – Time [μs ]
Output
R1
㎃
I
K
CL
R2
GND
0
Unstable
Regions
A
B
V
KA
V
ref
10V
R
1
[KΩ]
0
10
R
2
[KΩ]
∞
3.325
Fig.15 Test circuit for Fig. 14
㎌
KSD-I0A003-000
5