TL431 / TL431A / TL431B
PRODUCTION DATA SHEET
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 1
Copyright © 1999
Rev. 1.4, 2006-09-26
WWW.Microsemi .COM
Precision programmable References
TM ®
OBSOLETE PRODUCT
NOT RECOMMENDED FOR NEW DESIGNS
DESCRIPTION
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 200mΩ.
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.
IMPORTANT: For the most current data, consult MICROSEMI’s website: http://www.microsemi.com
KEY FEATURES
INITIAL VOLTAGE REFERENCE
ACCURACY OF 0.4% (TL431B)
SINK CURRENT CAPABILITY 1mA
to 100mA
TYPICAL OUTPUT DYNAMIC
IMPEDANCE LESS THAN 200mΩ;
TYPICAL OUTPUT IMPEDANCE OF
THE TL431B LESS THAN 100mΩ
ADJUSTABLE OUTPUT VOLTAGE
FROM 2.5V TO 36V
AVAILABLE IN SURFACE-MOUNT
PACKAGES
LOW OUTPUT NOISE
TYPICAL EQUIVALENT FULL
RANGE TEMPERATURE
COEFFICIENT OF 30ppm/°C
DIRECT PIN-TO-PIN
REPLACEMENT FOR INDUSTRY
STANDARD TL431 AND TL1431
PRODUCT HIGHLIGHT
Precision Programmable References
TL431/A
& TL431B
R1
R2
VOUT
VIN
OREF
R1
V=1+ •V
R2
⎛⎞
⎜⎟
⎝⎠
PACKAGE ORDER INFO
DM Plastic SOIC
8-Pin LP Plastic TO-92
3-Pin PK Plastic TO-89
3 - Pin
TA (°C) Initial
Tolerance RoHS Compliant / Pb-free
Transition DC: 0440
RoHS Compliant / Pb-free
Transition DC: 0509
RoHS Compliant / Pb-free
Transition DC: 0518
2% TL431CDM TL431CLP TL431CPK
1% TL431ACDM TL431ACLP TL431ACPK
0 to 70
0.4% TL431BCDM TL431BCLP TL431BCPK
2% TL431IDM TL431ILP TL431IPK
1% TL431AIDM TL431AILP TL431AIPK
-40 to 85
0.4% TL431BIDM TL431BILP TL461BIPK
Note: All surface mount packages are available in Tape & Reel. Append the letters “TR” to the part number. (i.e. LTL431AIDM-TR). The
TO-92 (LP) package is available in ammo-pack.
T
TL
L4
43
31
1X
X
TL431 / TL431A / TL431B
PRODUCTION DATA SHEET
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 2
Copyright © 1999
Rev. 1.4, 2006-09-26
WWW.Microsemi .COM
Precision programmable References
TM ®
OBSOLETE PRODUCT
NOT RECOMMENDED FOR NEW DESIGNS
ABSOLUTE MAXIMUM RATINGS
Cathode to Anode Voltage (VKA)(Note 2) ....................................................... -0.3 to 37V
Reference Input Current (IREF).................................................................. -50µA to 10mA
Continuous Cathode Current (IK).......................................................... -100mA to 150mA
Operating Junction Temperature................................................................................ 150°C
Storage Temperature Range.........................................................................-65°C to 150°C
Package Peak Temp. for Solder Reflow (40 seconds maximum exposure) ... 260°C (+0 -5)
Note: Exceeding these ratings could cause damage to the device. All voltages are with respect to
Ground. Currents are positive into, negative out of specified terminal.
Note 2. Voltage values are with respect to the anode terminal unless otherwise noted.
THERMAL DATA
DM Plastic SOIC 8-Pin
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA 165°C/W
PK Plastic TO-89 3-Pin
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA 71°C/W
LP Plastic TO-92 3-Pin
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA 156°C/W
Junction Temperature Calculation: TJ = TA + (PD x θJA).
The θJA numbers are guidelines for the thermal performance of the device/pc-board system. All of the
above assume no ambient airflow.
BLOCK DIAGRAM
Cathode (K)
Anode (A)
VREF
Ref (R)
PACKAGE PIN OUT
3. Cathode
2. Anode
1. Ref
LP PACKAGE
(Top View)
1
2
3
45
6
7
8
Cathode
N.C.
Anode
N.C. N.C.
Anode
Anode
Ref
DM PACKAGE
(Top View)
1
2
3
Ref
Anode
Cathode
PK PACKAGE
(Top View)
RoHS / Pb-free 100% Matte Tin Lead Finish
P
PA
AC
CK
KA
AG
GE
E
D
DA
AT
TA
A
TL431 / TL431A / TL431B
PRODUCTION DATA SHEET
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 3
Copyright © 1999
Rev. 1.4, 2006-09-26
WWW.Microsemi .COM
Precision programmable References
TM ®
OBSOLETE PRODUCT
NOT RECOMMENDED FOR NEW DESIGNS
ELECTRICAL CHARACTERISTICS
Unless otherwise specified, these specifications apply over the operating ambient temperature for the TL431C/TL431AC/TL431BC with
0°C < TA < 70°C, and TL431I/TL431AI/TL431BI with -40°C < TA < 85°C
TL431/A/B
Parameter Symbol Test Conditions Min Typ Max
Units
TL431 IK = 10mA, VKA = VREF, TA = 25°C 2440 2495 2550
TL431A IK = 10mA, VKA = VREF, TA = 25°C 2470 2495 2520
Reference Input
Voltage TL431B
VREF
IK = 10mA, VKA = VREF, TA = 25°C 2490 2500 2510
mV
TL431C IK = 10mA, VKA = VREF 4 17
TL431I IK = 10mA, VKA = VREF 5 30
TL431AC IK = 10mA, VKA = VREF 4 17
TL431AI IK = 10mA, VKA = VREF 5 30
TL431BC IK = 10mA, VKA = VREF 4 15
Reference Drift
TL431BI
KA
REF
ΔV
ΔV
IK = 10mA, VKA = VREF 5 20
mV
TL431,
TL431A IK = 10mA, VKA = 2.5V to 36V -1.4 -2.7
Voltage Ratio, Ref to
Cathode (Note 4) TL431B
IK = 10mA, VKA = 2.5V to 36V -1.1 -2.0
mV/V
TL431,
TL431A VKA = VREF, TA = 25°C 2 4
Reference Input
Current TL431B
IREF
VKA = VREF, TA = 25°C 1.5 1.9
µA
Minimum Operating Current IMIN VKA = VREF to 36V 0.4 1 mA
TL431 VKA = VREF to 36V, TA= 25°C 0.1 1
TL431A VKA = VREF to 36V, TA= 25°C 0.1 1
VKA = VREF to 36V, TA= Operating Range 2
Off-State Cathode
Current TL431B
IOFF
VKA = 36V, VREF = 0V, TA= 25°C 0.18 0.5
µA
TL431 I ZKA I VKA = VREF, IK = 1mA to 100mA, f < 1kHz,
TA = 25°C 0.2 0.5
Dynamic Impedance
TL431B VKA = VREF, IK = 1mA to 100mA, f < 1kHz,
TA = 25°C 0.1 0.2
Ω
Note 3: These parameters are guaranteed by design.
Note 4:
KA
REF
ΔV
ΔV
Ratio of change in reference input voltage to the change in cathode voltage.
E
EL
LE
EC
CT
TR
RI
IC
CA
AL
LS
S
TL431 / TL431A / TL431B
PRODUCTION DATA SHEET
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 4
Copyright © 1999
Rev. 1.4, 2006-09-26
WWW.Microsemi .COM
Precision programmable References
TM ®
OBSOLETE PRODUCT
NOT RECOMMENDED FOR NEW DESIGNS
GRAPH / CURVE INDEX
FIGURE INDEX
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
Parameter Measurement Information
Figure #
8. Test Circuit For VKA = VREF
9. Test Circuit For VKA > VREF
10. Test Circuit for IOFF
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
C
CH
HA
AR
RT
TS
S
TL431 / TL431A / TL431B
PRODUCTION DATA SHEET
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 5
Copyright © 1999
Rev. 1.4, 2006-09-26
WWW.Microsemi .COM
Precision programmable References
TM ®
OBSOLETE PRODUCT
NOT RECOMMENDED FOR NEW DESIGNS
CHARACTERISTIC CURVES
2.44
2.4
(TA) Ambient Temperature - (°C)
-50 -25 0 25 50 75 100 125
VREF
= V KA
IK = 10mA
2.42
2.46
2.48
2.50
2.52
2.54
2.56
2.58
2.60
VREF
= 2550mV
VREF
= 2495mV
VREF
= 2440mV
TL431B
TL431/A
TL431/A
TL431/A
(VREF) Reference Input Voltage - (V)
Figure 1 – Reference Voltage vs. Free-Air Temperature
1
0
(TA) Ambient Temperature - (°C)
5
2
-50 -25 0 25 50 75 100 125
3
IK = 10mA
R1 =
IK = 10mA
4
TL431/A
TL431B
(IREF) Reference Input Cur rent - (µA)
Figure 2 – Reference Current vs. Free-Air Temperature
0
-100
(VKA ) Cathode Voltage - (V)
150
-2 -1 0 123
50
VKA = VREF
T
A = 25 °C
100
-75
-50
-25
25
75
125
TL431/A
TL431B
(IK) Cathode Current - (µA)
Figure 3 – Cathode Current vs. Cathode Voltage
0
-200
(VKA) Cathode Voltage - (V)
800
200
-1 0 123
400
IMIN
600
VKA = VREF
T
A = 25°C
(IK) Cathode Current - (µA)
Figure 4 – Cathode Current vs. Cathode Voltage
C
CH
HA
AR
RT
TS
S
TL431 / TL431A / TL431B
PRODUCTION DATA SHEET
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 6
Copyright © 1999
Rev. 1.4, 2006-09-26
WWW.Microsemi .COM
Precision programmable References
TM ®
OBSOLETE PRODUCT
NOT RECOMMENDED FOR NEW DESIGNS
CHARACTERISTIC CURVES
0
(TA) Ambi ent Temperature - (°C)
2.5
-50 -25 0 25 50 75 100 125
VKA = 36V
VREF
= 0
0.5
1
1.5
2
TL431/A
& TL431B
(IOFF) Off-State Cathode Current - (µA)
Figure 5 – Off-State Cathode Current vs Free-Air Temperature
-1.25
-1.45
(TA) Ambient Temperature - (°C)
-0.85
-1.15
-50 -25 0 25 50 75 100 125
VKA = 3V to 36V
-1.35
-1.05
-0.95
VREF / VKA - (mV/V)
Figure 6 – Ratio of Delta Reference Voltage to Delta Cathode
Voltage vs. Free-Air Temperature
120
100
(f) Frequency - (Hz)
260
140
10 100 1k 10k 100k
200
220
160
180
240 IO = 10mA
T
A = 25 °C
(VN) Noise Voltage - (nV/ Hz)
Figure 7 – Equivalent Input Noise Voltage vs. Frequency
C
CH
HA
AR
RT
TS
S
TL431 / TL431A / TL431B
PRODUCTION DATA SHEET
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 7
Copyright © 1999
Rev. 1.4, 2006-09-26
WWW.Microsemi .COM
Precision programmable References
TM ®
OBSOLETE PRODUCT
NOT RECOMMENDED FOR NEW DESIGNS
PARAMETER MEASUREMENT INFORMATION
VKA
Input
VREF
IK
Figure 8 – Test Circuit for VKA = VREF
VKA
Input
VREF
IK
R1
R2
IREF
Figure 9 – Test Circuit for VKA > VREF
VKA
Input
IOFF
Figure 10 – Test Circuit for IOFF
A
AP
PP
PL
LI
IC
CA
AT
TI
IO
ON
NS
S
TL431 / TL431A / TL431B
PRODUCTION DATA SHEET
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 8
Copyright © 1999
Rev. 1.4, 2006-09-26
WWW.Microsemi .COM
Precision programmable References
TM ®
OBSOLETE PRODUCT
NOT RECOMMENDED FOR NEW DESIGNS
TYPICAL CHARACTERISTICS
-5
-6
(t) Time - (s)
5
-3
02468
1
2
-2
-1
3
f = 0.1 to 10Hz
IK = 10mA
T
A = 25 °C
-4
0
4
10
6
(VN) Input Noise Voltage - (µV)
Figure 11 – Equivalent Input Noise Voltage over a 10 – Second Period
19.1V
1k
910
2000µF
TL431/A
& TL431B (DUT)
2000µF
820
16
500µF
0.1µF
160K
16k 16k
1µF
VCC
VEE
TLE2027
AV = 10V/mV
1µF 33k
33k
VEE
VCC
TLE2027 2.2µF
CRO
1M
AV = 2V/V
Test Circuit for 0.1Hz to 10Hz Equivalent Input Noise Voltage
A
AP
PP
PL
LI
IC
CA
AT
TI
IO
ON
NS
S
TL431 / TL431A / TL431B
PRODUCTION DATA SHEET
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 9
Copyright © 1999
Rev. 1.4, 2006-09-26
WWW.Microsemi .COM
Precision programmable References
TM ®
OBSOLETE PRODUCT
NOT RECOMMENDED FOR NEW DESIGNS
TYPICAL CHARACTERISTICS
1k 100k 10M
-10
20
(f) Frequency - (Hz)
0
50
10k 1M
30
40
60
70
10
IK = 10mA
T
A = 25 °C
(AY) Voltage Amplification - (dB)
Figure 12 – Reference Impedance vs. Frequency
9µF
15k
8.25k
230
Output
GND
IK
Test Circuit for Voltage Amplification
1k 100k
0.1
10
(f) Frequency - ( Hz)
1
100
10k 1M 10M
IK = 1mA to 100mA
T
A = 25 °C
(IzKAI) Reference Impedan ce
Figure 13 – Reference Impedance vs. Frequency
50
1k
IK
Output
GND
Test Circuit for Reference Impedance
C
CH
HA
AR
RT
TS
S
TL431 / TL431A / TL431B
PRODUCTION DATA SHEET
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 10
Copyright © 1999
Rev. 1.4, 2006-09-26
WWW.Microsemi .COM
Precision programmable References
TM ®
OBSOLETE PRODUCT
NOT RECOMMENDED FOR NEW DESIGNS
TYPICAL CHARACTERISTICS
05
0
(t) Time - (µs)
6
2
1
2
213 4
4
1
0
3
3
5
6
VIN - (V)
(VKA)
Output Voltage - (V)
Figure 14 – Pulse Response
GND
Output
220
50
Pulse
Generator
f = 100kHz
Test Circuit for Pulse Response
0
40
(CL) Load Capacitance - (µF)
20
50
10
60
70
30
0.001 0.01 0.1 1 10
80
IK = 10mA
T
A = 25 °C
90
100
A V KA = VREF
B V KA = 5V
C V KA = 10V
D V KA = 15V
Stable
C*
D*
A*
B*
Stable
(IK) Cathode Cu r rent - mA
Figure 15 – Stability Boundary Conditions
*The areas under the curves represent conditions that may cause the device
to oscillate. For curves B, C, and D, R2 and V+ were adjusted to establish the
initial VKA and IK conditions with CL = 0. VBATT and CL were then adjusted to
determine the ranges of stability.
CL
150
IK
VBATT
R1=10k
R2
Test Circuit for Curve A
CL
IK
VBATT
150
Test Circuit for Curve B, C, D
C
CH
HA
AR
RT
TS
S
TL431 / TL431A / TL431B
PRODUCTION DATA SHEET
Microsemi
Integrated Products Division
11861 Western Avenue, Garden Grove, CA. 92841, 714-898-8121, Fax: 714-893-2570
Page 11
Copyright © 1999
Rev. 1.4, 2006-09-26
WWW.Microsemi .COM
Precision programmable References
TM ®
OBSOLETE PRODUCT
NOT RECOMMENDED FOR NEW DESIGNS
APPLICATION INFORMATION
IK
R1 0.1%
R2 0.1%
VREFTL431/A
& TL431B
VBATT VO
R (see Note)
REFO V
R2
R1
1V •+= ⎟
⎠
⎞
⎜
⎝
⎛
Figure 16 – Shunt Regulator
Note: R should provide > 1mA cathode current to the TL431/A & TL1431 at
minimum VBATT
Input VON 2V
VOFF VBATT
GND
VBATT
VO
TL431/A
& TL431B
Figure 17 – Single-Supply Comparator with Temperature-
Compensated Threshold
R1
R2
VBATT VO
TL431/A
& TL431B
REFO V
R2
R1
1V •+= ⎟
⎠
⎞
⎜
⎝
⎛
Figure 18 – High Current Shunt Regulator
R1
R2
VBATT VO
C
(see Note)
TL431/A
& TL431B
Figure 19 – Crowbar Circuit
Note: Refer to the stability boundary conditions in Figure 15 to determine
allowable values for C.
R1A
R2A
12V
(Note)
R2B
R3 (see Note)
R4
TL431/A
& TL431B
REF
REF
V
R2B
R1B
1LimitHigh
V
R2B
R1B
1Limit Low
•+=
•+=
⎟
⎠
⎞
⎜
⎝
⎛
⎟
⎠
⎞
⎜
⎝
⎛
LED on when Low Limit < VBATT < High Limit
Figure 20 – Voltage Monitor
Note: R3 and R4 are selected to provide the desired LED intensity and > 1mA
cathode current to the TL431/A & TL431B at the available V+
RS
0.1%
VBATT
IO
TL431/A
& TL431B
Figure 21 – Precision Contact – Current Sink
A
AP
PP
PL
LI
IC
CA
AT
TI
IO
ON
NS
S
