Precision Adjustable
Shunt Reference
TL431
FEATURES
•• Trimmed 1% Bandgap Reference
•• Nomi nal Temper atur e Range Exte nded to 10 5oC
•• Temperature-Compensated: 30ppm/oC
•• Int er nal Ampl ifi er w ith 1 50mA C apabili ty
•• Low Output Noise
•• Lo w Frequenc y Dynami c Output Imp edance
DESCRIPTION
The TL431 is an adjustable shunt regulat or design ed to ac t as
an open-loop error amplifier with a 2.5V temperature
compensated reference. Its highly accurate 1% bandgap
reference is perfect for applications requiring stability and
accur acy ov er tem p er atur e and life .
Sharp turn-on characteristics and a low temperature coefficient
make the TL431 an excellent replacement for many zener
diode applications, programmable to any value greater than
2.5V and up to 36V by using two external resistors. As a
combination error amplifier and reference, it can be used to
mana ge con trol loops such as sw itching power supp lies.
ORDERING INFORMAT ION
Part Package Temperature Range
TL431LP TO-92 0 to 105oC
TL431D 8-P in Plastc SOIC 0 to 105oC
TL431S SOT-89 0 to 105oC
CORPORATION
CAL OG IC CO RPO RATION , 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
CATHODE
ANODE
REFERENCE
TO-92 (LP)
1G-33
SOIC (D)
8
7
6
5
1
2
3
4
REFERENCE
ANODE
ANODE
N/C
CATHODE
ANODE
ANODE
N/C
1G-34
1G-35
CATHODE
ANODE
REFERENCE
SOT-89 (S)
PIN CONFIGUR ATIO N (Top View)
TL431
ABSOLUTE M AXIM UM R A T INGS
SYMBOL PARAMETER RATING UNITS
VKA Cathode-Anode Reverse Breakdown 37 V
IAK Anode-Cathode Forward Current 1 A
IKA Operating Cathode Current 250 mA
IREF Re fere nce Input Current 10 mA
PDCo ntinu ou s Power at 25 oC
TO-92
8L SOIC
SOT-89
775
750
1000
mW
mW
mW
TJJunction Temperature 150 oC
TSTG Storage Temperature –65 to 150 oC
TLLead Temperature, Soldering 10 Seconds 300 oC
Stre sses g reater tha n those li sted unde r ABSOLUTE MAXIMUM RATINGS may cause pe rmane nt damag e to the device . This is a stress rating
only and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification
is n ot im plied . Expo sure to ab so lut e m a ximu m rati ng co nditi on s for ext en ded peri od s m a y a ffe ct reliab ilit y.
RECOM MENDED CONDIT IONS
SYMBOL PARAMETER RATING UNIT
VKA Cathode Voltage VREF to 20 V
IKCathode Current 10 mA
TYPICAL THERMAL RESISTANCE
PACKAGE θJA θJC TYPICAL DERATING
TO-92 160oC/W 80oC/W 6.3mW/oC
SOIC 175oC/W 45oC/W 5.7mW/oC
SOT-89 110oC/W 8oC/W 9.1mW/oC
CAL OG IC CO RPO RATION , 237 Whitney Place, Fremont, Cal ifornia 94539, Telephone: 510-656-2900, FAX: 510-651-3025
1G-36
ANODE (A)
CATHODE (K)
2.5V
REFERENCE (R) +
–
FUNCTIONAL BLOCK DIAGRAM
CORPORATION
TL431
CAL OG IC CO RPO RATION , 237 Whitney Place, Fremont, Cal ifornia 94539, Telephone: 510-656-2900, FAX: 510-651-3025
ELECTRICA L CHARACTERI STICS
Elect ri cal Ch ara cteristics are guara nt eed over full junct ion tem peratu re ran ge (0 to 105 oC). Ambient tem p era ture must be derated ba sed on
power dissipation and package thermal characteristics. The conditions are: VKA = VREF and IK = 10mA unless otherwise stated .
SYMBOL PARAMETER MIN TYP MAX UNIT TEST CIRCUIT TEST CONDITION
VREF Reference Voltage 2.470 2.495 2.520 V 1 TA = 25oC
2.449 2.541 V 1 Over Temp.
TC ∆VREF with Temp.* 0.07 0.20 mV/oC1
∆VREF
∆VKRatio of Change in VREF to
Cathode Voltage –2.7 –1.0 mV/V 2 VREF to 10V
–2 – 0. 4 0. 3 1 0V t o 36V
IREF Reference Input Current 0.7 4 µA2
∆IREF IREF Temp Deviation 0.4 1.2 µA 2 Over Temp.
IK(MIN) Min IK for Regulation 0.4 1 mA 1
IK(OFF) Off State Leakage 0.04 250 nA 3 VREF = 0V, VKA = 36V
ZKA Dynam ic Output Impedance 0.1 5 0.5 Ω1f ≤ 1kHz, IK = 1 to 150mA
015 30 45 60 75 90 105
TEMPERATURE (˚C)
0.07 mV/˚C
0.003 %/˚C
27 ppm/˚C
0.55000
000
mV
%
ppm
–10
∆V
REF
∆T
1G-37
• TC in mV/oC = ∆VREF (mV)
∆TA
• TC in %/oC =
∆VREF
VREF at 25oC
x 100
∆TA
• TC in ppm/ oC =
∆VREF
VREF at 25oC
x 10 6
∆TA
*CALCULATING AVERAGE TEMPERATURE COEF FICIENT (TC)
TEST CIRCUIT S
IN
V
KA
V
K
I
1G-38
REF
I
REF
= V
REF
I
IN
V
KA
V
2
R
1
R
REF
(V )
K
I
1G-39
IN
V
KA
V
K(OFF)
I
1G-40
TEST CIRCUIT 1 TEST CIRCUIT 2 TEST CIRCUI T 3
CORPORATION
TL431
TYPICAL PERFO RM ANCE CU RV ES
CAL OG IC CO RPO RATION , 237 Whitney Place, Fremont, Cal ifornia 94539, Telephone: 510-656-2900, FAX: 510-651-3025
100
0.01
–60
1G-43
OFF STATE LEAKAGE
–30 0 306090120
10
1
0.1
CURRENT (nA)
VKA = 36V
VREF = 0V
– AMBIENT TEMPERATURE (˚C)TA
– OFF STATE CATHODEIZoff
150
–100
–2 3
1G-42
HIGH CURRENT OPERATING
CHARACTERISTICS
75
50
25
0
–25
–50
–75
125
100
210–1
– CATHODE VOLTAGE (V)VKA
TEMPERATURE RANGE: –55 to 125˚C
VKA = VREF
– CATHODE CURRENT (mA)
IK
2.54
2.46
–60
1G-44
TEMPERAT URE COEFFICIENT AS
A FUNCTION OF TRIM VALUE
–30
2.47
2.48
2.49
2.50
2.51
2.52
2.53
0
30 60 90 120
V
REF
– REFERENCE VOLTAGE (V)
– AMBIENT TEMPERATURET
A
V
KA
= V
REF
I
K
= 10mA
V
REF
= 2.503V AT 25˚C
VKA – CATHODE VOLTAGE (V)
– CATHODE CURRENT (µA)
IK
900
–200
–1.0 3.0
1G-41
LOW CURRENT OPERATING
CHARACTERISTICS
1.00 2.0
–100
800
700
600
500
400
300
200
100
0
125˚C
–55˚C
25˚C
V= V
REFKA
TEMPERATURE RANGE: –55 to 125˚C
0
–50030
1G-46
REFERENCE VOLTAGE
LINE REGULATION
3 6 9 12 15 18 21 24 27
–10
–20
–30
–40
VOLTAGE (mV)
– CHANGE IN REFERENCEVREF
– CATHODE VOLTAGE (V)VKA
IK= 10mA
TEMPERATURE RANGE: –55 to 125˚C
–55˚C
0˚C
25˚C
75˚C
125˚C
3.0
0
–60
1G-45
REFERENCE
INPUT CURRENT
–30 0 306090120
2.5
2.0
1.5
1.0
0.5
CURRENT (µA)
– REFERENCE INPUTIREF
TA– AMBIENT TEMPERATURE (˚C)
R1 = 10kΩ
R2 = ∞
IK= 10mA
CORPORATION
TL431
CAL OG IC CO RPO RATION , 237 Whitney Place, Fremont, Cal ifornia 94539, Telephone: 510-656-2900, FAX: 510-651-3025
TYPICAL PERFO RM ANCE CU RVES (continued)
70
010
1G-47
NOISE VOLTAGE
100k
f – FREQUENCY (Hz)
60
50
40
30
20
10
10k1k100
NOISE VOLTAGE nV/ Hz
VKA = VREF
= 10mA
TA= 25˚C
IK
0.150
0.0
–60
1G-48
LOW FREQUENCY DYNAMIC
OUTPUT IMPEDANCE
–30 0 306090120
0.125
0.100
0.075
0.050
0.025
– DYNAMIC IMPEDANCE (Ω)
ZKA
VKA = VREF
= 1 TO 100mA
f ≤ 1kHz
IKA
– FREE AIR TEMPERATURETA
100
0.011k
1G-49
DYNAMIC OUTPUT
IMPEDANCE
10M
f – FREQUENCY (Hz)
1M100k10k
10
1.0
0.1
– DYNAMIC IMPEDANCE (Ω)
ZKA
TA= 25˚C
= 1 TO 100mAIK
70
01k
1G-50
SMALL SIGNAL G AIN
vs FREQUENCY
10M
f – FREQUENCY (Hz)
60
50
40
30
20
10
1M
100k10k
I
K
= 10mA
GAIN (dB)
– SMALL SIGNAL VOLTAGE
A
V
T
A
= 25˚C
1H-01
K
I230Ω
GND
OUT
15k
8.25k
9µF
CORPORATION
TL431
100
010 10
1H-04
7
STABILITY BOUNDARY
CONDITIONS
90
80
70
60
50
40
30
20
10
101010101010 6543210
TA= 25˚C
A
C
D
– CATHODE CURRENT (mA)
IK
B
A: V
KA
= V
REF
B: VKA = 5V AT I
K
= 10mA
C: VKA = 10V AT IK= 10mA
D: VKA = 15V AT IK= 10mA
STABILITY
REGION
– LOAD CAPACITANCE (pF)CL
6
–10
1H-02
PULSE RESPONSE
t – TIME (µs)
INPUT AND OUTPUT VOLTAGES (V)
121234567891011
4
3
2
1
0
5INPUT
OUTPUT
1H-03
GND
OUT
220
Ω
INPUT
MONITOR
50Ω
f
P
= 100 kH z
1H-05
K
I
L
C
150Ω
10k
TYPICAL PERFO RM ANCE CU RVES (continued)
CAL OG IC CO RPO RATION , 237 Whitney Place, Fremont, Cal ifornia 94539, Telephone: 510-656-2900, FAX: 510-651-3025
CORPORATION
