Equivalent Full-Range Temperature
Coefficient . . . 30 ppm/°C
D
0.2-Ω Typical Output Impedance
D
Sink-Current Capability ...1 mA to 100 mA
D
Low Output Noise
D
Adjustable Output Voltage ...V
D
Available in a Wide Range of High-Density
ref
Packages
description
The TL431 and TL431A are three-terminal
adjustable shunt regulators with specified thermal
stability over applicable automotive, commercial,
and military temperature ranges. The output
voltage can be set to any value between V
(approximately 2.5 V) and 36 V with two external
resistors (see Figure 17). These devices have a
typical output impedance of 0.2 Ω. Active output
circuitry provides a very sharp turn-on
characteristic, making these devices excellent
replacements for Zener diodes in many
applications, such as onboard regulation,
adjustable power supplies, and switching power
supplies.
The TL431C and TL431AC are characterized for
operation from 0°C to 70°C, and the TL431I and
TL431AI are characterized for operation from
–40°C to 85°C.
to 36 V
ref
D PACKAGE
(TOP VIEW)
CATHODE
ANODE
ANODE
CATHODE
NC – No internal connection
1
2
3
4
NC
P OR PW PACKAGE
(TOP VIEW)
1
NC
2
NC
3
4
NC
PK PACKAGE
(TOP VIEW)
REF ANODE CATHODE
LP PACKAGE
(TOP VIEW)
8
7
6
5
8
7
6
5
REF
ANODE
ANODE
NC
REF
NC
ANODE
NC
CATHODE
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
ANODE
ANODE
REF
KTP PACKAGE
(TOP VIEW)
CATHODE
ANODE
REF
Copyright 1999, Texas Instruments Incorporated
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
1
TL431, TL431A
TL431Y
ADJUSTABLE PRECISION SHUNT REGULATORS
SLVS005J – JULY 1978 – REVISED JULY 1999
AVAILABLE OPTIONS
PACKAGED DEVICES
T
A
0°C to 70°C
–40°C to 85°C
The D and LP packages are available taped and reeled. The KTP and PK packages are only available taped and reeled. Add
the suffix R to device type (e.g., TL431CDR). Chip forms are tested at TA = 25°C.
SMALL
OUTLINE
(D)
TL431CD
TL431ACD
TL431ID
TL431AID
symbol
functional block diagram
PLASTIC
FLANGE
MOUNT
(KTP)
TL431CKTPR
TO-226AA
(LP)
TL431CLP
TL431ACLP
TL431ILP
TL431AILP
REF
PLASTIC
DIP
(P)
TL431CP
TL431ACP
TL431IP
TL431AIP
CATHODEANODE
SOT-89
(PK)
TL431CPKTL431CPW
TL431IPK
SHRINK
SMALL
OUTLINE
(PW)
CHIP
FORM
(Y)
equivalent schematic
CATHODE
REF
†
2.4 kΩ
3.28 kΩ
7.2 kΩ
REF
V
ref
CATHODE
ANODE
20 pF
+
_
800 Ω
4 kΩ
800 Ω
20 pF
150 Ω
10 kΩ
ANODE
†
All component values are nominal.
2
1 kΩ
800 Ω
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Operating free-air temperature range, T
°C
TL431, TL431A
ADJUSTABLE PRECISION SHUNT REGULATORS
SLVS005J – JULY 1978 – REVISED JULY 1999
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds: D, P, or PW package 260°C. . . . . . . . . . . .
Lead temperature 1,6 mm (1/16 inch) from case for 60 seconds: LP or PK package 300°C. . . . . . . . . . . . . .
Storage temperature range, T
†
Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
NOTES: 1. Voltage values are with respect to the anode terminal unless otherwise noted.
2. Maximum power dissipation is a function of TJ(max),
ambient temperature is PD = (TJ(max) – TA)/
3. The package thermal impedance is calculated in accordance with JESD 51, except for through-hole packages, which use a trace
length of zero.
, and TA. The maximum allowable power dissipation at any allowable
θ
JA
JA
. Operating at the absolute maximum TJ of 150°C can impact reliability.
recommended operating conditions
MINMAXUNIT
Cathode voltage, V
Cathode current, I
p
KA
KA
p
A
TL431C, TL431AC070
TL431I, TL431AI–4085
V
ref
36V
1100mA
°
†
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
3
TL431, TL431A
PARAMETER
TEST CONDITIONS
UNIT
ref
gg
3
I
mA
mV
ADJUSTABLE PRECISION SHUNT REGULATORS
SLVS005J – JULY 1978 – REVISED JULY 1999
electrical characteristics over recommended operating conditions, TA = 25°C (unless otherwise
noted)
TL431C
MINTYPMAX
425mV
–1.4–2.7
V
0.41.2µA
0.41mA
0.20.5Ω
V
ref
V
I(dev)
D
V
D
V
I
ref
I
I(dev)
I
min
I
off
|zKA|Dynamic impedance (see Figure 1)1
†
Full range is 0°C to 70°C for the TL431C.
Reference voltage2VKA = V
Deviation of reference voltage
over full temperature range
(see Figure 1)
Ratio of change in reference voltage
to the change in cathode voltage
KA
Reference current3IKA = 10 mA, R1 = 10 kΩ, R2 = ∞24µA
Deviation of reference current
over full temperature range
(see Figure 1)
Minimum cathode current
for regulation
Off-state cathode current4VKA = 36 V,V
TEST
CIRCUIT
2
3
2VKA = V
,IKA = 10 mA244024952550mV
ref
VKA = V
TA = full range
= 10
KA
IKA = 10 mA, R1 = 10 kΩ, R2 = ∞,
TA = full range
IKA = 1 mA to 100 mA, VKA = V
f ≤ 1 kHz
ref, IKA
ref
= 10 mA,
†
∆VKA = 10 V – V
∆VKA = 36 V – 10 V–1–2
†
= 00.11µA
ref
ref
ref
,
The deviation parameters V
ref(dev)
and I
ref(dev)
are defined as the differences between the maximum and minimum
values obtained over the recommended temperature range. The average full-range temperature coefficient of the
reference voltage, α
Ť
a
Vref
ppm
Ť
ǒ
°C
, is defined as:
Vref
ǒ
V
Ǔ
+
V
ref
)
I(dev
at 25°C
D
T
A
10
6
Minimum V
Ǔ
Maximum V
ref
ref
∆T
V
I(dev)
A
where:
∆TA is the recommended operating free-air temperature range of the device.
α
can be positive or negative, depending on whether minimum V
Vref
or maximum V
ref
, respectively , occurs at the
ref
lower temperature.
Example: maximum V
= 2496 mV at 30°C, minimum V
ref
= 2492 mV at 0°C, V
ref
= 2495 mV at 25°C,
ref
∆TA = 70°C for TL431C
4mV
ǒ
Ť
+
2495 mV
Ť
a
Vref
Because minimum V
Ǔ
70°C
occurs at the lower temperature, the coefficient is positive.
ref
Calculating Dynamic Impedance
The dynamic impedance is defined as:
10
6
[
23 ppmń°C
Ť
Ť
z
+
KA
D
V
KA
D
I
KA
When the device is operating with two external resistors (see Figure 3), the total dynamic impedance of the circuit
is given by:
D
|
z
Ȁ|+
V
[Ťz
D
I
KA
Ť
R1
ǒ
1
)
R2
Ǔ
4
Figure 1. Calculating Deviation Parameters and Dynamic Impedance
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
PARAMETER
TEST CONDITIONS
UNIT
ref
gg
3
I
mA
mV
PARAMETER
TEST CONDITIONS
UNIT
ref
gg
3
I
mA
mV
TL431, TL431A
ADJUSTABLE PRECISION SHUNT REGULATORS
SLVS005J – JULY 1978 – REVISED JULY 1999
electrical characteristics over recommended operating conditions, TA = 25°C (unless otherwise
noted)
TL431I
MINTYPMAX
550mV
–1.4–2.7
V
0.82.5µA
0.41mA
0.20.5Ω
V
ref
V
I(dev)
D
V
D
V
I
ref
I
I(dev)
I
min
I
off
|zKA|Dynamic impedance (see Figure 1)2
†
Full range is –40°C to 85°C for the TL431I.
Reference voltage2VKA = V
Deviation of reference voltage
over full temperature range
(see Figure 1)
Ratio of change in reference voltage
to the change in cathode voltage
KA
Reference current3IKA = 10 mA, R1 = 10 kΩ, R2 = ∞24µA
Deviation of reference current
over full temperature range
(see Figure 1)
Minimum cathode current for
regulation
Off-state cathode current4VKA = 36 V,V
TEST
CIRCUIT
2
3
2VKA = V
,IKA = 10 mA244024952550mV
ref
VKA = V
TA = full range
= 10
KA
IKA = 10 mA, R1 = 10 kΩ, R2 = ∞,
TA = full range
IKA = 1 mA to 100 mA, VKA = V
f ≤ 1 kHz
ref, IKA
ref
= 10 mA,
†
∆VKA = 10 V – V
∆VKA = 36 V – 10 V–1–2
†
= 00.11µA
ref
ref
ref
,
electrical characteristics over recommended operating conditions, TA = 25°C (unless otherwise
noted)
TL431AC
MINTYPMAX
425mV
–1.4–2.7
V
0.81.2µA
0.40.6mA
0.20.5Ω
V
ref
V
I(dev)
D
V
D
V
I
ref
I
I(dev)
I
min
I
off
|zKA|Dynamic impedance (see Figure 1)1
‡
Full range is 0°C to 70°C for the TL431AC.
Reference voltage2VKA = V
Deviation of reference voltage
over full temperature range
(see Figure 1)
Ratio of change in reference voltage
to the change in cathode voltage
KA
Reference current3IKA = 10 mA, R1 = 10 kΩ, R2 = ∞24µA
Deviation of reference current
over full temperature range
(see Figure 1)
Minimum cathode current
for regulation
Off-state cathode current4VKA = 36 V,V
TEST
CIRCUIT
2
3
2VKA = V
,IKA = 10 mA247024952520mV
ref
VKA = V
TA = full range
= 10
KA
IKA = 10 mA, R1 = 10 kΩ, R2 = ∞,
TA = full range
IKA = 1 mA to 100 mA, VKA = V
f ≤ 1 kHz
ref, IKA
ref
= 10 mA,
†
∆VKA = 10 V – V
∆VKA = 36 V – 10 V–1–2
‡
= 00.10.5µA
ref
ref
ref
,
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
5
TL431, TL431A
PARAMETER
TEST CONDITIONS
UNIT
ref
gg
3
I
mA
mV
PARAMETER
TEST CONDITIONS
UNIT
ref
gg
3
I
mA
mV
ADJUSTABLE PRECISION SHUNT REGULATORS
SLVS005J – JULY 1978 – REVISED JULY 1999
electrical characteristics over recommended operating conditions, TA = 25°C (unless otherwise
noted)
TL431AI
MINTYPMAX
550mV
–1.4–2.7
V
0.82.5µA
0.40.7mA
0.20.5Ω
V
ref
V
I(dev)
D
V
D
V
I
ref
I
I(dev)
I
min
I
off
|zKA|Dynamic impedance (see Figure 1)2
†
Full range is –40°C to 85°C for the TL431AI.
Reference voltage2VKA = V
Deviation of reference voltage
over full temperature range
(see Figure 1)
Ratio of change in reference voltage
to the change in cathode voltage
KA
Reference current3IKA = 10 mA, R1 = 10 kΩ, R2 = ∞24µA
Deviation of reference current
over full temperature range
(see Figure 1)
Minimum cathode current
for regulation
Off-state cathode current4VKA = 36 V,V
TEST
CIRCUIT
2
3
2VKA = V
,IKA = 10 mA247024952520mV
ref
VKA = V
TA = full range
= 10
KA
IKA = 10 mA, R1 = 10 kΩ, R2 = ∞,
TA = full range
IKA = 1 mA to 100 mA, VKA = V
f ≤ 1 kHz
ref, IKA
ref
= 10 mA,
†
∆VKA = 10 V – V
∆VKA = 36 V – 10 V–1–2
†
= 00.10.5µA
ref
ref
ref
,
electrical characteristics over recommended operating conditions, TA = 25°C (unless otherwise
noted)
TEST
CIRCUIT
V
ref
D
V
D
V
I
ref
I
min
I
off
|zKA|Dynamic impedance
‡
Calculating dynamic impedance:
The dynamic impedance is defined as:
When the device is operating with two external resistors (see Figure 3), the total dynamic impedance of the circuit is given by:
|zȀ|
Reference voltage2VKA = V
Ratio of change in reference voltage