D E S C R I P T I O N
K E Y F E A T U R E S
W INITIAL VOLTAGE REFERENCE ACCURACY OF
0.4% (TL431B)
W SINK CURRENT CAPABILITY 1mA to 100mA
W TYPICAL OUTPUT DYNAMIC IMPEDANCE
LESS THAN 200m
Ω
;
TYPICAL OUTPUT IMPEDANCE OF THE
TL431B LESS THAN 100m
Ω
W ADJUSTABLE OUTPUT VOLTAGE FROM 2.5V
TO 36V
W AVAILABLE IN SURFACE-MOUNT PACKAGES
W LOW OUTPUT NOISE
W TYPICAL EQUIVALENT FULL RANGE
TEMPERATURE COEFFICIENT OF 30ppm/°C
W DIRECT PIN-TO-PIN REPLACEMENT FOR
INDUSTRY STANDARD TL431 AND TL1431
The TL431/TL431A/TL431B series
precision adjustable three terminal shunt
voltage regulators are pin-to-pin
compatible with the industry standard
TL431. The output voltage of this
reference is programmable by using two
external resistors from 2.5V to 36V.
These devices offer low output
impedance for improved load regulation.
The typical output impedance of these
devices is 200m
Ω
. These devices find
application in the feedback path of
switching power supplies, OVP
crowbar circuits, reference for A/D,
D/A, and as zener diodes with
improved turn-on characteristics.
P
R E C I S I O N
P
R O G R A M M A B L E
R
E F E R E N C E S
P R O D U C T H I G H L I G H T
P A C K A G E O R D E R I N F O R M A T I O N
T
A
(°C)
Initial
Tolerance
Plastic SOIC
8-pin
DM
Plastic TO-92
3-pin
LP
2%
TL431CDM
TL431CLP
0 to 70
1%
TL431ACDM
TL431ACLP
0.4%
TL431BCDM
TL431BCLP
2%
TL431IDM
TL431ILP
-40 to 85
1%
TL431AIDM
TL431AILP
0.4%
TL431BIDM
TL431BILP
TL431/A
& TL431B
R1
R2
V
OUT
V
IN
R1
R2
V
O
= 1 +
* V
REF
Note: All surface-mount packages are available in Tape & Reel.
Append the letter "T" to part number. (i.e. TL431CDMT)
TO-92 (LP) package also available in ammo-pack.
P
R E C I S I O N
P
R O G R A M M A B L E
R
E F E R E N C E S
P
R O D U C T I O N
D
A T A
S
H E E T
T
H E
I
N F I N I T E
P
O W E R
O F
I
N N O V A T I O N
TL431/TL431A/TL431B
Copyright © 1999
Rev. 1.3 9/99
1
11861 W
ESTERN
A
VENUE
, G
ARDEN
G
ROVE
, CA. 92841, 714-898-8121, F
AX
: 714-893-2570
L
I N
F
I N I T Y
M
I C R O E L E C T R O N I C S
I
N C
.
NOTE: For current data & package dimensions, visit our web site: http://www.linfinity.com.
P
R E C I S I O N
P
R O G R A M M A B L E
R
E F E R E N C E S
TL431/TL431A/TL431B
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
Copyright © 1999
Rev. 1.3 9/99
2
P
R O D U C T I O N
D
A T A
S
H E E T
ABSOLUTE MAXIMUM RATINGS
(Note 1)
Cathode to Anode Voltage (V
KA
) (Note 2) .................................................... -0.3V to 37V
Reference Input Current (I
REF
) ................................................................... -50µA to 10mA
Continuous Cathode Current (I
K
) ......................................................... -100mA to 150mA
Operating Junction Temperature
Plastic (DM, LP Packages) .................................................................................... 150°C
Storage Temperature Range ...................................................................... -65°C to 150°C
Lead Temperature ..................................................................................................... 300°C
PACKAGE PIN OUTS
CATHODE
N.C.
ANODE
N.C.
1
8
2
7
3
6
4
5
REF
ANODE
ANODE
N.C.
DM PACKAGE
(Top View)
LP PACKAGE
(Top View)
1. CATHODE
2. ANODE
3. REF
Note 1. Exceeding these ratings could cause damage to the device. All voltages are with respect
to Ground. Currents are positive into, negative out of the specified terminal. Pin
numbers refer to DIL packages only.
Note 2. Voltage values are with respect to the anode terminal unless otherwise noted.
BLOCK DIAGRAM
Cathode (K)
Anode (A)
V
REF
Ref (R)
DM PACKAGE:
THERMAL RESISTANCE-JUNCTION TO AMBIENT,
θθθθθ
JA
165°C/W
LP PACKAGE:
THERMAL RESISTANCE-JUNCTION TO AMBIENT,
θθθθθ
JA
156°C/W
Junction Temperature Calculation: T
J
= T
A
+ (P
D
x
θ
JA
).
The
θ
JA
numbers are guidelines for the thermal performance of the device/pc-board system.
All of the above assume no ambient airflow
THERMAL DATA
P
R E C I S I O N
P
R O G R A M M A B L E
R
E F E R E N C E S
TL431/TL431A/TL431B
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
3
Copyright © 1999
Rev. 1.3 9/99
P
R O D U C T I O N
D
A T A
S
H E E T
E L E C T R I C A L C H A R A C T E R I S T I C S
(Note 3)
(Unless otherwise specified, these specifications apply over the operating ambient temperatures for TL431C/TL431AC/TL431BC with 0°C
≤
T
A
≤
70°C,
TL431I/TL431AI/TL431BI with -40°C
≤
T
A
≤
85°C.)
Parameter
Symbol
Test Conditions
TL431/431A/431B
Units
Min. Typ. Max.
2440 2495 2550
mV
2470 2495 2520
mV
2490 2500 2510
mV
4
17
mV
5
30
mV
4
17
mV
5
30
mV
4
15
mV
5
20
mV
-1.4
-2.7
mV/V
-1.1
-2
mV/V
2
4
µA
1.5
1.9
µA
2.3
µA
0.4
1
mA
0.1
1
µA
0.1
1
µA
2
µA
0.18
0.5
µA
0.2
0.5
Ω
0.1
0.2
Ω
Note 3. These parameters are guaranteed by design.
Note 4.
Ratio of change in reference input voltage
to the change in cathode voltage.
∆
V
REF
∆
V
KA
Reference Input Voltage
TL431
V
REF
I
K
= 10mA, V
KA
= V
REF
, T
A
= 25°C
TL431A
I
K
= 10mA, V
KA
= V
REF
, T
A
= 25°C
TL431B
I
K
= 10mA, V
KA
= V
REF
, T
A
= 25°C
Reference Drift
TL431C
I
K
= 10mA, V
KA
= V
REF
TL431I
I
K
= 10mA, V
KA
= V
REF
TL431AC
∆
V
REF
I
K
= 10mA, V
KA
= V
REF
TL431AI
∆
V
KA
I
K
= 10mA, V
KA
= V
REF
TL431BC
I
K
= 10mA, V
KA
= V
REF
TL431BI
I
K
= 10mA, V
KA
= V
REF
Voltage Ratio, Ref to Cathode
TL431, TL431A
I
K
= 10mA, V
KA
= 2.5V to 36V
(Note 4)
TL431B
I
K
= 10mA, V
KA
= 2.5V to 36V
Reference Input Current
TL431,TL431A
I
REF
V
KA
= V
REF
, T
A
= 25°C
TL431B
V
KA
= V
REF
, T
A
= 25°C
V
KA
= V
REF
, T
A
= Operating Range
Minimum Operating Current
I
MIN
V
KA
= V
REF
to 36V
Off-State Cathode Current
TL431
I
OFF
V
KA
= V
REF
to 36V, T
A
= 25°C
TL431A
V
KA
= V
REF
to 36V, T
A
= 25°C
TL431B
V
KA
= V
REF
to 36V, T
A
= Operating Range
V
KA
= 36V, V
REF
= 0V, T
A
= 25°C
Dynamic Impedance
TL431
| Z
KA
|
V
KA
= V
REF
, I
K
= 1mA to 100mA, f
≤
1kHz, T
A
= 25°C
TL431B
V
KA
= V
REF
, I
K
= 1mA to 100mA, f
≤
1kHz, T
A
= 25°C
P
R E C I S I O N
P
R O G R A M M A B L E
R
E F E R E N C E S
TL431/TL431A/TL431B
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
Copyright © 1999
Rev. 1.3 9/99
4
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R O D U C T I O N
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A T A
S
H E E T
Characteristic Curves
FIGURE #
1.
REFERENCE INPUT VOLTAGE vs. FREE-AIR TEMPERATURE
2.
REFERENCE INPUT CURRENT vs. FREE-AIR TEMPERATURE
3.
CATHODE CURRENT vs. CATHODE VOLTAGE
4.
CATHODE CURRENT vs. CATHODE VOLTAGE
5.
OFF-STATE CATHODE CURRENT vs. FREE-AIR TEMPERATURE
6.
RATIO OF DELTA REFERENCE VOLTAGE TO DELTA CATHODE
VOLTAGE vs. FREE-AIR TEMPERATURE
7.
EQUIVALENT INPUT NOISE VOLTAGE vs. FREQUENCY
GRAPH / CURVE INDEX
FIGURE INDEX
Parameter Measurement Information
FIGURE #
8.
TEST CIRCUIT FOR V
KA
= V
REF
9.
TEST CIRCUIT FOR V
KA
> V
REF
10. TEST CIRCUIT FOR I
OFF
Typical Characteristics
FIGURE #
11. EQUIVALENT INPUT NOISE VOLTAGE OVER A 10-SECOND PERIOD
12. SMALL-SIGNAL VOLTAGE AMPLIFICATION vs. FREQUENCY
13. REFERENCE IMPEDANCE vs. FREQUENCY
14. PULSE RESPONSE
15. STABILITY BOUNDARY CONDITIONS
Application Information
FIGURE #
16. SHUNT REGULATOR
17. SINGLE-SUPPLY COMPARATOR WITH TEMPERATURE-COMPENSATED
THRESHOLD
18. HIGH CURRENT SHUNT REGULATOR
19. CROWBAR CIRCUIT
20. VOLTAGE MONITOR
21. PRECISION CONSTANT-CURRENT SINK
P
R E C I S I O N
P
R O G R A M M A B L E
R
E F E R E N C E S
TL431/TL431A/TL431B
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
5
Copyright © 1999
Rev. 1.3 9/99
P
R O D U C T I O N
D
A T A
S
H E E T
C H A R A C T E R I S T I C C U R V E S
FIGURE 2. —
REFERENCE CURRENT
vs. FREE-AIR TEMPERATURE
FIGURE 3. — CATHODE CURRENT vs. CATHODE VOLTAGE
FIGURE 4. — CATHODE CURRENT vs. CATHODE VOLTAGE
FIGURE 1. —
REFERENCE VOLTAGE
vs. FREE-AIR TEMPERATURE
1
0
(T
A
) Ambient Temperature - (°C)
5
(I
REF
) Reference Input Current - (µA)
2
-50
-25
0
25
50
75
100
125
3
I
K
= 10mA
R1 =
¥
I
K
= 10mA
4
TL431/A
TL431B
2.44
2.4
(T
A
) Ambient Temperature - (°C)
(V
REF
) Reference Input Voltage - (V)
-50
-25
0
25
50
75
100
125
V
REF
= V
KA
I
K
= 10mA
2.42
2.46
2.48
2.50
2.52
2.54
2.56
2.58
2.60
V
REF
= 2550mV
V
REF
= 2495mV
V
REF
= 2440mV
TL431B
TL431/A
TL431/A
TL431/A
0
-100
(V
KA
) Cathode Voltage - (V)
150
(I
K
) Cathode Current - (µA)
-2
-1
0
1
2
3
50
V
KA
= V
REF
T
A
= 25°C
100
-75
-50
-25
25
75
125
TL431/A
TL431B
0
-200
(V
KA
) Cathode Voltage - (V)
800
(I
K
) Cathode Current - (µA)
200
-1
0
1
2
3
400
I
MIN
600
V
KA
= V
REF
T
A
= 25°C
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R E C I S I O N
P
R O G R A M M A B L E
R
E F E R E N C E S
TL431/TL431A/TL431B
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
Copyright © 1999
Rev. 1.3 9/99
6
P
R O D U C T I O N
D
A T A
S
H E E T
C H A R A C T E R I S T I C C U R V E S
FIGURE 5. —
OFF-STATE CATHODE CURRENT
vs. FREE-AIR TEMPERATURE
0
(T
A
) Ambient Temperature - (°C)
2.5
(I
OFF
) Off-State Cathode Current - (µA)
-50
-25
0
25
50
75
100
125
V
KA
= 36V
V
REF
= 0
0.5
1
1.5
2
TL431/A
& TL431B
FIGURE 6. —
RATIO OF DELTA REFERENCE VOLTAGE TO DELTA
CATHODE VOLTAGE vs. FREE-AIR TEMPERATURE
-1.25
-1.45
(T
A
) Ambient Temperature - (°C)
-0.85
∆
V
REF
/
∆
V
KA
- (mV/V)
-1.15
-50
-25
0
25
50
75
100
125
V
KA
= 3V to 36V
-1.35
-1.05
-0.95
FIGURE 7. —
EQUIVALENT INPUT NOISE VOLTAGE
vs. FREQUENCY
120
100
(f) Frequency - (Hz)
260
(V
N
) Noise Voltage - (nV/ Hz)
140
10
100
1k
10k
100k
200
220
160
180
240
I
O
= 10mA
T
A
= 25°C
P
R E C I S I O N
P
R O G R A M M A B L E
R
E F E R E N C E S
TL431/TL431A/TL431B
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
7
Copyright © 1999
Rev. 1.3 9/99
P
R O D U C T I O N
D
A T A
S
H E E T
P A R A M E T E R M E A S U R E M E N T I N F O R M A T I O N
FIGURE 8 — TEST CIRCUIT FOR V
KA
= V
REF
V
KA
Input
V
REF
I
K
FIGURE 9 — TEST CIRCUIT FOR V
KA
> V
REF
V
KA
Input
V
REF
I
K
R
1
R
2
I
REF
FIGURE 10 — TEST CIRCUIT FOR I
OFF
V
KA
Input
I
OFF
P
R E C I S I O N
P
R O G R A M M A B L E
R
E F E R E N C E S
TL431/TL431A/TL431B
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
Copyright © 1999
Rev. 1.3 9/99
8
P
R O D U C T I O N
D
A T A
S
H E E T
T Y P I C A L C H A R A C T E R I S T I C S
-5
-6
(t) Time - (s)
5
(V
N
) Input Noise Voltage - (µV)
-3
0
2
4
6
8
1
2
-2
-1
3
f = 0.1 to 10Hz
I
K
= 10mA
T
A
= 25°C
-4
0
4
10
6
FIGURE 11. — EQUIVALENT INPUT NOISE VOLTAGE OVER A 10-SECOND PERIOD
19.1V
1k
W
910
W
2000µF
TL431/A
& TL431B (DUT)
2000µF
820
W
16
W
500µF
0.1µF
160k
W
16k
W
16k
W
1µF
V
CC
V
EE
TLE2027
A
V
= 10V/mV
1µF
33k
W
33k
W
V
EE
V
CC
TLE2027
2.2µF
CRO
1M
W
A
V
= 2V/V
Test Circuit for 0.1Hz to 10Hz Equivalent Input Noise Voltage
P
R E C I S I O N
P
R O G R A M M A B L E
R
E F E R E N C E S
TL431/TL431A/TL431B
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
9
Copyright © 1999
Rev. 1.3 9/99
P
R O D U C T I O N
D
A T A
S
H E E T
T Y P I C A L C H A R A C T E R I S T I C S
FIGURE 12. —
SMALL-SIGNAL VOLTAGE AMPLIFICATION
vs. FREQUENCY
9µF
15k
W
8.25k
W
230
W
Output
GND
I
K
Test Circuit for Voltage Amplification
1k
100k
10M
-10
20
(f) Frequency - (Hz)
(A
V
) Voltage Amplification - (dB)
0
50
10k
1M
30
40
60
70
10
I
K
= 10mA
T
A
= 25°C
FIGURE 13. — REFERENCE IMPEDANCE vs. FREQUENCY
1k
100k
0.1
10
(f) Frequency - (Hz)
(|z
KA
|) Reference Impedance - (
W
)
1
100
10k
1M
10M
I
K
= 1mA to 100mA
T
A
= 25°C
50
W
1k
W
I
K
Output
GND
Test Circuit for Reference Impedance
P
R E C I S I O N
P
R O G R A M M A B L E
R
E F E R E N C E S
TL431/TL431A/TL431B
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
Copyright © 1999
Rev. 1.3 9/99
10
P
R O D U C T I O N
D
A T A
S
H E E T
T Y P I C A L C H A R A C T E R I S T I C S
FIGURE 14. — PULSE RESPONSE
0
5
0
(t) Time - (µs)
6
V
IN
- (V)
2
1
2
2
1
3
4
4
1
(V
KA
)
Output Voltage - (V)
0
3
3
5
6
GND
Output
220
W
50
W
Pulse
Generator
f = 100kHz
Test Circuit for Pulse Response
FIGURE 15. — STABILITY BOUNDARY CONDITIONS
C
L
150
W
I
K
V
BATT
R1=10k
W
R2
0
40
(C
L
) Load Capacitance - (µF)
(I
K
) Cathode Current - mA
20
50
10
60
70
30
0.001
0.01
0.1
1
10
80
I
K
= 10mA
T
A
= 25°C
90
100
A V
KA
= V
REF
B V
KA
= 5V
C V
KA
= 10V
D V
KA