TL431A Adjustable Precision Shunt Regulator
1
FEATURES
Programmable Output Voltage to 36V
Low Dynamic Output Impedance 0.2
Sink Current Capability of 0.1 mA to 100 mA
Equivalent Full-Range Temperature Coefficient of 50 ppm/
o
C
Temperature Compensated for Operation over Full Rated
Operating Temperature Range
Low Output Noise Voltage
Fast Turn on Response
DESCRIPTION
The
TL431A is a three-terminal adjustable regulator series with a guaranteed thermal stability over applicable temperature ranges.
The output voltage may be set to any value between Vref (approximately 2.5 volts) and 36 volts with two external resistors. These
devices have a typical dynamic output impedance of 0.2
. Active output circuitry provides a very sharp turn-on characteristic,
making these devices excellent replacement for zener diodes in many applications.
The
TL431A is characterized for operation from -0
o
C to +70
o
C.
SYMBOL FUNCTIONAL BLOCK DIAGRAM
SCHEMATIC DIAGRAM
Wing Shing Computer Components Co., (H.K.)Ltd.
Tel:(852)2341 9276 Fax:(852)2797 8153
Homepage:
http://www.wingshing.com
E-mail: wsccltd@hkstar.com
TO-92
REF
ANODE
CATHODE
SOT-89
REF ANODE CATHODE
TL431CLP
TL431CPK
TL431A Adjustable Precision Shunt Regulator
2
ABSOLUTE MAXIMUM RATINGS
(Operating temperature range applies unless otherwise specified)
Characteristic
Symbol
Value
Unit
Cathode Voltage
V
KA
37
V
Cathode Current Range (Continuous)
I
K
-100 ~ +150
mA
Reference Input Current Range
I
REF
0.05 ~ +10
mA
Operating Temperature Range
T
A
0 ~ +70
o
C
Storage Temperature Range
T
stg
-65 ~ +150
o
C
RECOMMENDED OPERATING CONDITIONS
Characteristic
Symbol
Test Condition
Min
Typ
Max
Unit
Cathode Voltage
V
KA
V
REF
36
V
Cathode Current
I
K
1.0
100
mA
ELECTRICAL CHARACTERISTICS
(T
A
= 25
o
C, unless otherwise specified)
Characteristic
Symbol
Test Condition
Min
Typ
Max
Unit
Reference Input Voltage
V
REF
V
KA
=
V
REF
, I
K
= 10mA
2.475
2.495
2.515
V
Deviation of Reference Input Voltage
Over-Temperature (Note 1)
V
REF(dev)
V
KA
=
V
REF
, I
K
= 10mA
T
min
T
A
T
max
3
17
mV
Ratio of Change in Reference Input
Voltage to the Change in
V
V
R EF
K A
I
K
= 10mA
V
KA
=
10V-V
REF
-1.4
-2.7
mV/V
Cathode Voltage
K
KA
=
36V- 10V
-1.0
-2.0
Reference Input Current
I
REF
I
K
= 10mA, R
1
= 10K
, R
2
=
1,8
4
A
Deviation of Reference Input Current
Over Full Temperature Range
I
REF(dev)
I
K
= 10mA, R
1
= 10K
, R
2
=
Ta = Full Range
0.4
1.2
A
Minimum Cathode Current for
Regulation
I
K(min)
V
KA
=
V
REF
0.5
1.0
mA
Off-State Cathode Current
I
K(off)
V
KA
=
36V,
V
REF
= 0
0.26
1.0
A
Dynamic Impedance (Note2)
Z
KA
V
KA
=
V
REF
, I
K
= 10mA to 100mA
f
1.0KHz
0.22
0.4
Note: 1. The deviation parameters V
REF(dev)
and I
REF(dev)
are defined as the differences between the maximum and minimum values obtained over the rated
temperature range.
V
REF(dev)
= V
REF
(max) - V
REF
(min)
The equivalent full-range temperature coefficient of the reference
input voltage,
V
REF
is defined as:
V
REF
(
)
ppm
C
=
(
)
V
V
@
C
T a
R EF(dev)
R EF
10
6
Where
T
A
is the rated operating free-air temperature range of
the device.
V
REF
can be positive or negative depending on whether minimum V
REF
or
maximum V
REF
respectively, occurs at the
lower temperature.
2. The dynamic impedance is defined as:
Z
K A
=
V
I
K A
K
Wing Shing Computer Components Co., (H.K.)Ltd.
Tel:(852)2341 9276 Fax:(852)2797 8153
Homepage:
http://www.wingshing.com
E-mail: wsccltd@hkstar.com
A
A
A
TL431A Adjustable Precision Shunt Regulator
3
When the device is operated with two external resistors (see Figure 2), the total dynamic impedance of the circuit is given by:
Z
' =
V
I
=
Z
K A
(1+
R
R
1
2
)
TEST CIRCUITS
Fig.1. Test Circuit for V
KA
= V
REF
Fig.2. Test Circuit for V
KA
V
REF
Fig.3. Test Circuit for I
off
PAD LAYOUT
B T 431 P A D D IA G R A M
C h ip size: 1345 x 990
P ad size :
U n it :
m
(0,0)
2
3
4
1
Wing Shing Computer Components Co., (H.K.)Ltd.
Tel:(852)2341 9276 Fax:(852)2797 8153
Homepage:
http://www.wingshing.com
E-mail: wsccltd@hkstar.com
TL431A Adjustable Precision Shunt Regulator
4
PAD LOCATION
Unit:
m
Pad No.
Pad Name
Description
X
Y
1
R
Reference
235
400
2
K
Cathode
-505
343.5
3
K
Cathode
-497.5
-346
4
A
Anode
-177.5
-341.5
Physical Characteristics
Wafes
4
4 Wafes 460
40
m
Size
1.35
0.99 mm
Scribe width
90
m
Wafe's Backside
Ti Ni Ag: Ti - 0.1
0.02
m
Ni - 0.5
0.1
m
Ag - 0.6
0.1
m
Passivation
PSG
Wing Shing Computer Components Co., (H.K.)Ltd.
Tel:(852)2341 9276 Fax:(852)2797 8153
Homepage:
http://www.wingshing.com
E-mail: wsccltd@hkstar.com
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