TL431−Q1
ADJUSTABLE PRECISION SHUNT REGULATOR
SGLS302D MARCH 2005 REVISED MARCH 2013
1
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
DQualified for Automotive Applications
DOperation From 40°C to 125°C
DReference Voltage Tolerance at 25°C
1%...A Grade
0.5% ...B Grade
DTypical Temperature Drift
14 mV (Q Temp)
DLow Output Noise
D0.2-Ω Typical Output Impedance
DSink-Current Capability = 1 mA to 100 mA
DAdjustable Output Voltage = Vref to 36 V
description
The TL431 is a three-terminal adjustable shunt
regulator with specified thermal stability over
applicable automotive temperature ranges. The output voltage can be set to any value between Vref
(approximately 2.5 V) and 36 V, with two external resistors (see Figure 17). This device has a typical output
impedance of 0.2 Ω. Active output circuitry provides a sharp turn-on characteristic, making this device an
excellent replacement for Zener diodes in many applications, such as onboard regulation, adjustable power
supplies, and switching power supplies.
Ordering Information{
TAPACKAGEORDERABLE
PART NUMBER
TOP-SIDE
MARKING
SOT-23-5 (DBV) Reel of 3000 TL431AQDBVRQ1 TACQ
40°C to 125°CSOT-23-5 (DBV) Reel of 3000 TL431QDBVRQ1 T3QU
40 C to 125 C
SOT-23-3 (DBZ) Reel of 3000 TL431AQDBZRQ1 TAQU
For the most current package and ordering information, see the Package Option Addendum at the end of this
document, or see the TI web site at http://www.ti.com.
Package drawings, thermal data, and symbolization are available at http://www.ti.com/packaging.
symbol REF
CATHODEANODE
functional block diagram CATHODE
REF
ANODE
+
_
Vref
Copyright © 20082013, Texas Instruments Incorporated
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.
PowerFLEX is a trademark of Texas Instruments.
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.
NC No internal connection
DBV (SOT-23-5) PACKAGE
(TOP VIEW)
1
2
3
5
4
NC
NC
CATHODE
ANODE
REF
Pin 2 is connected internally to ANODE
(die substrate) and should be floating or
connected to ANODE.
TL431Q1
DBZ (SOT-23-3) PACKAGE
(TOP VIEW)
1
2
3
CATHODE
REF
ANODE
TL431−Q1
ADJUSTABLE PRECISION SHUNT REGULATOR
SGLS302D MARCH 2005 REVISED MARCH 2013
2POST OFFICE BOX 655303 DALLAS, TEXAS 75265
equivalent schematic{
ANODE
REF
CATHODE
2.4 kΩ7.2 kΩ
3.28 kΩ
20 pF
4 kΩ
1 kΩ
800 Ω
800 Ω800 Ω
20 pF
150 Ω
10 kΩ
All component values are nominal.
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Cathode voltage, VKA (see Note 1) 37 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Continuous cathode current range, IKA 100 mA to 150 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Reference input current range 50 μA to 10 mA. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating virtual junction temperature, TJ 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range, Tstg 65°C to 150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ESD protection level (see Note 2): HBM (H2) 2.5 kV. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CDM (C4) 1 kV. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MM (M2) 200 V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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.
NOTE 1: Voltage values are with respect to the ANODE terminal, unless otherwise noted.
NOTE 2: ESD Protection Level per AEC Q100 Classification
package thermal data (see Note3)
PACKAGE BOARD θJC θJA
SOT-23-5 (DBV) High K, JESD 51-7 131°C/W 206°C/W
SOT-23-3 (DBZ) High K, JESD 51-7 76°C/W 206°C/W
NOTE 3: Maximum power dissipation is a function of TJ(max), θJA, and TA. The maximum allowable power dissipation at any allowable ambient
temperature is PD = (TJ(max) TA)/θJA. Operating at the absolute maximum TJ of 150°C can affect reliability.
recommended operating conditions
MIN MAX UNIT
VKA Cathode voltage Vref 36 V
IKA Cathode current 1 100 mA
TAOperating free-air temperature range 40 125 °C
TL431−Q1
ADJUSTABLE PRECISION SHUNT REGULATOR
SGLS302D MARCH 2005 REVISED MARCH 2013
3
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
electrical characteristics over recommended operating conditions, TA = 25°C (unless otherwise
noted)
PARAMETER
TEST
TEST CONDITIONS
TL431Q
UNIT
PARAMETER
TEST
CIRCUIT TEST CONDITIONS MIN TYP MAX UNIT
Vref Reference voltage 2 VKA = Vref, IKA = 10 mA 2440 2495 2550 mV
VI(dev)
Deviation of reference voltage
over full temperature range
(see Figure 1)
2VKA = Vref, IKA = 10 mA,
TA = 40°C to 125°C14 34 mV
DV
ref
Ratio of chan
g
e in reference volta
g
e
3
I 10 mA
ΔVKA = 10 V Vref 1.4 2.7
mV
DV
ref
DVKA
Ratio of change in reference voltage
to the change in cathode voltage 3 IKA = 10 mA ΔVKA = 36 V 10 V 12
m
V
V
Iref Reference current 3 IKA = 10 mA, R1 = 10 kΩ, R2 = 2 4 μA
II(dev)
Deviation of reference current
over full temperature range
(see Figure 1)
3IKA = 10 mA, R1 = 10 kΩ, R2 = ,
TA = 40°C to 125°C0.8 2.5 μA
Imin Minimum cathode current for
regulation 2 VKA = Vref 0.4 1 mA
Ioff Off-state cathode current 4 VKA = 36 V, Vref = 0 0.1 1 μA
|zKA|Dynamic impedance (see Figure 1) 2IKA = 1 mA to 100 mA, VKA = Vref,
f 1 kHz 0.2 0.5 Ω
electrical characteristics over recommended operating conditions, TA = 25°C (unless otherwise
noted)
PARAMETER
TEST
TEST CONDITIONS
TL431AQ
UNIT
PARAMETER
TEST
CIRCUIT TEST CONDITIONS MIN TYP MAX UNIT
Vref Reference voltage 2 VKA = Vref, IKA = 10 mA 2470 2495 2520 mV
VI(dev)
Deviation of reference voltage
over full temperature range
(see Figure 1)
2VKA = Vref, IKA = 10 mA,
TA = 40°C to 125°C14 34 mV
DV
ref
Ratio of chan
g
e in reference volta
g
e
3
I 10 mA
ΔVKA = 10 V Vref 1.4 2.7
mV
DV
ref
DVKA
Ratio of change in reference voltage
to the change in cathode voltage 3 IKA = 10 mA ΔVKA = 36 V 10 V 12
m
V
V
Iref Reference current 3 IKA = 10 mA, R1 = 10 kΩ, R2 = 2 4 μA
II(dev)
Deviation of reference current
over full temperature range
(see Figure 1)
3IKA = 10 mA, R1 = 10 kΩ, R2 = ,
TA = 40°C to 125°C0.8 2.5 μA
Imin Minimum cathode current
for regulation 2 VKA = Vref 0.4 0.7 mA
Ioff Off-state cathode current 4 VKA = 36 V, Vref = 0 0.1 0.5 μA
|zKA|Dynamic impedance (see Figure 1) 2IKA = 1 mA to 100 mA, VKA = Vref,
f 1 kHz 0.2 0.5 Ω
TL431−Q1
ADJUSTABLE PRECISION SHUNT REGULATOR
SGLS302D MARCH 2005 REVISED MARCH 2013
4POST OFFICE BOX 655303 DALLAS, TEXAS 75265
electrical characteristics over recommended operating conditions, TA = 25°C (unless otherwise
noted)
PARAMETER
TEST
TEST CONDITIONS
TL431BQ
UNIT
PARAMETER
TEST
CIRCUIT TEST CONDITIONS MIN TYP MAX UNIT
Vref Reference voltage 2 VKA = Vref, IKA = 10 mA 2483 2495 2507 mV
VI(dev)
Deviation of reference voltage
over full temperature range
(see Figure 1)
2VKA = Vref, IKA = 10 mA,
TA = 40°C to 125°C14 34 mV
DV
ref
Ratio of chan
g
e in reference volta
g
e
3
I 10 mA
ΔVKA = 10 V Vref 1.4 2.7
mV
DV
re
f
DVKA
Ratio of change in reference voltage
to the change in cathode voltage 3 IKA = 10 mA ΔVKA = 36 V 10 V 12
m
V
V
Iref Reference current 3 IKA = 10 mA, R1 = 10 kΩ, R2 = 2 4 μA
II(dev)
Deviation of reference current
over full temperature range
(see Figure 1)
3IKA = 10 mA, R1 = 10 kΩ, R2 = ,
TA = 40°C to 125°C0.8 2.5 μA
Imin Minimum cathode current
for regulation 2 VKA = Vref 0.4 0.7 mA
Ioff Off-state cathode current 4 VKA = 36 V, Vref = 0 0.1 0.5 μA
|zKA|Dynamic impedance (see Figure 1) 1IKA = 1 mA to 100 mA, VKA = Vref,
f 1 kHz 0.2 0.5 Ω
The deviation parameters, Vref(dev) and Iref(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, αVref, is defined as:
where:
ΔTA is the recommended operating free-air temperature range of the device.
can be positive or negative, depending on whether minimum Vref or maximum Vref, respectively, occurs at the
lower temperature.
Example: maximum Vref = 2496 mV at 30°C, minimum Vref = 2492 mV at 0°C, Vref = 2495 mV at 25°C,
ΔTA = 70°C for TL431
Because minimum Vref occurs at the lower temperature, the coefficient is positive.
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:
Maximum Vref
Minimum Vref
ΔTA
VI(dev)
ŤaVrefŤǒppm
°CǓ+ǒVI(dev)
Vref at 25°CǓ 106
DTA
ŤaVref Ť+ǒ4mV
2495 mVǓ 106
70°C[23 ppm
°C
|zKA|+DVKA
DIKA
|zȀ|+DV
DI[|zKA|ǒ1)R1
R2Ǔ
aVref
Figure 1. Calculating Deviation Parameters and Dynamic Impedance
TL431−Q1
ADJUSTABLE PRECISION SHUNT REGULATOR
SGLS302D MARCH 2005 REVISED MARCH 2013
5
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
PARAMETER MEASUREMENT INFORMATION
Vref
Input VKA
IKA
Figure 2. Test Circuit for VKA = Vref
VKA +Vrefǒ1)R1
R2Ǔ)Iref R1
Iref
IKA
VKA
Input
Vref
R1
R2
Figure 3. Test Circuit for VKA > Vref
Ioff
VKA
Input
Figure 4. Test Circuit for Ioff
TL431−Q1
ADJUSTABLE PRECISION SHUNT REGULATOR
SGLS302D MARCH 2005 REVISED MARCH 2013
6POST OFFICE BOX 655303 DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
Table 1. Graphs
FIGURE
Reference voltage vs Free-air temperature 5
Reference current vs Free-air temperature 6
Cathode current vs Cathode voltage 7, 8
OFF-state cathode current vs Free-air temperature 9
Ratio of delta reference voltage to delta cathode voltage vs Free-air temperature 10
Equivalent input noise voltage vs Frequency 11
Equivalent input noise voltage over a 10-s period 12
Small-signal voltage amplification vs Frequency 13
Reference impedance vs Frequency 14
Pulse response 15
Stability boundary conditions 16
Table 2. Application Circuits
FIGURE
Shunt regulator 17
Single-supply comparator with temperature-compensated threshold 18
Precision high-current series regulator 19
Output control of a three-terminal fixed regulator 20
High-current shunt regulator 21
Crowbar circuit 22
Precision 5-V 1.5-A regulator 23
Efficient 5-V precision regulator 24
PWM converter with reference 25
Voltage monitor 26
Delay timer 27
Precision current limiter 28
Precision constant-current sink 29
TL431−Q1
ADJUSTABLE PRECISION SHUNT REGULATOR
SGLS302D MARCH 2005 REVISED MARCH 2013
7
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS{
Data is for devices having the indicated value of Vref at IKA = 10 mA,
TA = 25°C.
Figure 5
2500
2480
2420
2400
75 50 25 0 25 50 75
2540
2580
REFERENCE VOLTAGE
vs
FREE-AIR TEMPERATURE
2600
100 125
2460
2560
2520
2440
TA Free-Air Temperature °C
Vref = 2495 mV
Vref = 2440 mV
VKA = Vref
IKA = 10 mA
Vref = 2550 mV
Reference Voltage mV
Vref
3
2
1
0
75 25 0 50
4
REFERENCE CURRENT
vs
FREE-AIR TEMPERATURE
5
100 12550 25 75
TA Free-Air Temperature °C
R1 = 10 kΩ
R2 =
IKA = 10 mA
Reference Current ref
IAμ
Figure 6
Figure 7
25
0
50
75
100
125
25
210 1
75
50
100
CATHODE CURRENT
vs
CATHODE VOLTAGE
150
23
VKA Cathode Voltage V
VKA = Vref
TA = 25°C
Cathode Current mAIKA
Figure 8
400
200
0
200
10 1
600
CATHODE CURRENT
vs
CATHODE VOLTAGE
800
23
VKA = Vref
TA = 25°C
VKA Cathode Voltage V
Imin
Cathode Current IKA Aμ
Data at high and low temperatures is applicable only within the recommended operating free-air temperature ranges of the various devices.
TL431−Q1
ADJUSTABLE PRECISION SHUNT REGULATOR
SGLS302D MARCH 2005 REVISED MARCH 2013
8POST OFFICE BOX 655303 DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS{
Figure 9
1.5
1
0.5
0
75 25 0 50
Off-State Cathode Current
2
OFF-STATE CATHODE CURRENT
vs
FREE-AIR TEMPERATURE
2.5
100 12550 25 75
Ioff Aμ
TA Free-Air Temperature °C
VKA = 36 V
Vref = 0
Figure 10
1.15
1.25
1.35
1.45
1.05
0.95
RATIO OF DELTA REFERENCE VOLTAGE TO
DELTA CATHODE VOLTAGE
vs
FREE-AIR TEMPERATURE
0.85
TA Free-Air Temperature °C
75 25 0 50 100 12550 25 75
VKA = 3 V to 36 V
mV/V
ΔVref ΔVKA
/
180
140
120
100
10 100 1 k
220
240
f Frequency Hz
EQUIVALENT INPUT NOISE VOLTAGE
vs
FREQUENCY
260
10 k 100 k
200
160
Equivalent Input Noise Voltage nV/ HzVn
IO = 10 mA
TA = 25°C
Figure 11
Data at high and low temperatures is applicable only within the recommended operating free-air temperature ranges of the various devices.
TL431−Q1
ADJUSTABLE PRECISION SHUNT REGULATOR
SGLS302D MARCH 2005 REVISED MARCH 2013
9
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
19.1 V
VCC
TLE2027
TLE2027
AV = 10 V/mV
VEE
0.1 μF
160 kΩ
820 Ω
(DUT)
TL431
16 Ω
910 Ω
2000 μF
1 kΩ
VEE
VCC
1 μF
16 kΩ16 kΩ
1 μF33 kΩ
33 kΩ
AV = 2 V/V
22 μF
500 μF
To
Oscilloscope
1
2
4
5
6
3
3
0123456
1
0
2
EQUIVALENT INPUT NOISE VOLTAGE
OVER A 10-S PERIOD
4
78910
5
6
t Time s
f = 0.1 to 10 Hz
IKA = 10 mA
TA = 25°C
Equivalent Input Noise Voltage μV
Vn
+
+
Figure 12. Test Circuit for Equivalent Input Noise Voltage
TL431−Q1
ADJUSTABLE PRECISION SHUNT REGULATOR
SGLS302D MARCH 2005 REVISED MARCH 2013
10 POST OFFICE BOX 655303 DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
1 k 10 k 100 k 1 M 10 M
0
10
20
30
50
60
40
SMALL-SIGNAL VOLTAGE AMPLIFICATION
vs
FREQUENCY
9 μF
GND
Output
232 Ω
8.25 kΩ
IKA
15 kΩ
f Frequency Hz
TEST CIRCUIT FOR VOLTAGE AMPLIFICATION
IKA = 10 mA
TA = 25°C
Small-Signal Voltage Amplification dBAV
+
IKA = 10 mA
TA = 25°C
Figure 13
1 kΩ
50 Ω
GND
Output
IKA
0.1
1 k 10 k 100 k 1 M 10 M
1
f Frequency Hz
REFERENCE IMPEDANCE
vs
FREQUENCY
10
100
IKA = 10 mA
TA = 25°C
TEST CIRCUIT FOR REFERENCE IMPEDANCE
Reference Impedance
KA
|z | Ω
+
Figure 14
TL431−Q1
ADJUSTABLE PRECISION SHUNT REGULATOR
SGLS302D MARCH 2005 REVISED MARCH 2013
11
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
3
2
1
0
10 1 2 3 4
Input and Output Voltage V
4
5
PULSE RESPONSE
6
567
Input
Output
TA = 25°C
220 Ω
50 Ω
GND
Output
Pulse
Generator
f = 100 kHz
TEST CIRCUIT FOR PULSE RESPONSE
t Time μs
Figure 15
TL431−Q1
ADJUSTABLE PRECISION SHUNT REGULATOR
SGLS302D MARCH 2005 REVISED MARCH 2013
12 POST OFFICE BOX 655303 DALLAS, TEXAS 75265
TYPICAL CHARACTERISTICS
50
40
10
0
0.001 0.01 0.1 1
70
90
STABILITY BOUNDARY CONDITIONS
FOR ALL TL431 AND TL431A DEVICES
(EXCEPT FOR SOT23-3, SC-70, AND Q-TEMP DEVICES)
100
10
30
80
60
20
TA = 25°C
B
Stable
Stable
A VKA = Vref
B VKA = 5 V
C VKA = 10 V
D VKA = 15 Vf
CL Load Capacitance μF
A
C
D
150 Ω
IKA
R1 = 10 kΩ
R2
CL
VBATT
IKA
CLVBATT
150 Ω
TEST CIRCUIT FOR CURVE A
TEST CIRCUIT FOR CURVES B, C, AND D
Cathode Current mA
IKA
+
+
50
40
10
0
0.001 0.01 0.1 1
70
90
STABILITY BOUNDARY CONDITIONS
FOR ALL TL431B, TL432, SOT-23, SC-70, AND Q-TEMP DEVICES
100
10
30
80
60
20
Stable
A VKA = Vref
B VKA = 5 V
C VKA = 10 V
D VKA = 15 Vf
CL Load Capacitance μF
A
C
D
150 Ω
IKA
R1 = 10 kΩ
R2
CL
VBATT
IKA
CLVBATT
150 Ω
TEST CIRCUIT FOR CURVE A
TEST CIRCUIT FOR CURVES B, C, AND D
Cathode Current mA
IKA
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 IKA conditions with CL = 0. VBATT and
CL then were adjusted to determine the ranges of stability.
+
+
B
A
TA = 25°C
Stable
B
Figure 16
TL431−Q1
ADJUSTABLE PRECISION SHUNT REGULATOR
SGLS302D MARCH 2005 REVISED MARCH 2013
13
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
APPLICATION INFORMATION
R1
0.1%
R2
0.1%
R
(see Note A)
Vref
VO
TL431
VI(BATT)
RETURN
NOTE A: R should provide cathode current 1 mA to the TL431 at minimum VI(BATT).
VO+ǒ1)R1
R2ǓVref
Figure 17. Shunt Regulator
VO
TL431
VI(BATT)
VIT 2.5 V
GND
Input Von 2 V
Voff VI(BATT)
Figure 18. Single-Supply Comparator With Temperature-Compensated Threshold
R
(see Note A)
VO
TL431
VI(BATT)
2N222
2N222
4.7 kΩ
R1
0.1%
R2
0.1%
0.01 μF
30 Ω
VO+ǒ1)R1
R2ǓVref
NOTE A: R should provide cathode current 1 mA to the TL431 at minimum VI(BATT).
Figure 19. Precision High-Current Series Regulator
TL431−Q1
ADJUSTABLE PRECISION SHUNT REGULATOR
SGLS302D MARCH 2005 REVISED MARCH 2013
14 POST OFFICE BOX 655303 DALLAS, TEXAS 75265
APPLICATION INFORMATION
VO
TL431
VI(BATT)
uA7805
IN
OUT
Common R1
R2
VO+ǒ1)R1
R2ǓVref
Minimum VO+Vref )5V
Figure 20. Output Control of a Three-Terminal Fixed Regulator
VO
TL431
VI(BATT)
R1
R2
VO+ǒ1)R1
R2ǓVref
Figure 21. High-Current Shunt Regulator
VO
TL431
VI(BATT)
R1
R2
NOTE A: See the stability boundary conditions in Figure 16 to determine allowable values for C.
C
(see Note A)
Figure 22. Crowbar Circuit
TL431−Q1
ADJUSTABLE PRECISION SHUNT REGULATOR
SGLS302D MARCH 2005 REVISED MARCH 2013
15
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
APPLICATION INFORMATION
VO 5 V, 1.5 A
TL431
VI(BATT) LM317
IN OUT
Adjust
243 Ω
0.1%
243 Ω
0.1%
8.2 kΩ
Figure 23. Precision 5-V 1.5-A Regulator
VO 5 V
TL431
VI(BATT)
27.4 kΩ
0.1%
Rb
(see Note A)
27.4 kΩ
0.1%
NOTE A: Rb should provide cathode current 1 mA to the TL431.
Figure 24. Efficient 5-V Precision Regulator
TL431
12 V
VCC
5 V
6.8 kΩ
10 kΩ
10 kΩ
0.1%
10 kΩ
0.1%
X
Not
Used
Feedback
TL598
+
Figure 25. PWM Converter With Reference
TL431−Q1
ADJUSTABLE PRECISION SHUNT REGULATOR
SGLS302D MARCH 2005 REVISED MARCH 2013
16 POST OFFICE BOX 655303 DALLAS, TEXAS 75265
APPLICATION INFORMATION
TL431
VI(BATT)
R3
(see Note A)
R1A R4
(see Note A)
R2BR2A
NOTE A: R3 and R4 are selected to provide the desired LED intensity and cathode current 1 mA to the TL431 at the available VI(BATT).
R1B
Low Limit +ǒ1)R1B
R2BǓVref
High Limit +ǒ1)R1A
R2AǓVref
LED on When Low Limit < VI(BATT) < High Limit
Figure 26. Voltage Monitor
TL431
650 Ω
2 kΩ
C
On
Off
R
12 V
Delay +R C Inǒ12 V
12 V *VrefǓ
Figure 27. Delay Timer
TL431
IO
RCL
0.1%
R1
VI(BATT) Iout +Vref
RCL )IKA
R1 +VI(BATT)
IO
hFE )IKA
Figure 28. Precision Current Limiter
TL431−Q1
ADJUSTABLE PRECISION SHUNT REGULATOR
SGLS302D MARCH 2005 REVISED MARCH 2013
17
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
APPLICATION INFORMATION
TL431
RS
0.1%
IO
VI(BATT)
IO+Vref
RS
Figure 29. Precision Constant-Current Sink
PACKAGE OPTION ADDENDUM
www.ti.com 11-Apr-2013
Addendum-Page 1
PACKAGING INFORMATION
Orderable Device Status
(1)
Package Type Package
Drawing Pins Package
Qty Eco Plan
(2)
Lead/Ball Finish MSL Peak Temp
(3)
Op Temp (°C) Top-Side Markings
(4)
Samples
TL431AQDBVRQ1 ACTIVE SOT-23 DBV 5 3000 Green (RoHS
& no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 TACQ
TL431AQDBZRQ1 ACTIVE SOT-23 DBZ 3 3000 Green (RoHS
& no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 TAQU
TL431BQDBZRQ1 ACTIVE SOT-23 DBZ 3 3000 Green (RoHS
& no Sb/Br) CU NIPDAU Level-1-260C-UNLIM -40 to 125 T3FU
(1) The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability
information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that
lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight
in homogeneous material)
(3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4) Multiple Top-Side Markings will be inside parentheses. Only one Top-Side Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a
continuation of the previous line and the two combined represent the entire Top-Side Marking for that device.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
PACKAGE OPTION ADDENDUM
www.ti.com 11-Apr-2013
Addendum-Page 2
OTHER QUALIFIED VERSIONS OF TL431A-Q1, TL431B-Q1 :
Catalog: TL431A, TL431B
NOTE: Qualified Version Definitions:
Catalog - TI's standard catalog product
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device Package
Type Package
Drawing Pins SPQ Reel
Diameter
(mm)
Reel
Width
W1 (mm)
A0
(mm) B0
(mm) K0
(mm) P1
(mm) W
(mm) Pin1
Quadrant
TL431AQDBVRQ1 SOT-23 DBV 5 3000 179.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3
TL431AQDBZRQ1 SOT-23 DBZ 3 3000 179.0 8.4 3.15 2.95 1.22 4.0 8.0 Q3
TL431BQDBZRQ1 SOT-23 DBZ 3 3000 179.0 8.4 3.15 2.95 1.22 4.0 8.0 Q3
PACKAGE MATERIALS INFORMATION
www.ti.com 14-Mar-2013
Pack Materials-Page 1
*All dimensions are nominal
Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)
TL431AQDBVRQ1 SOT-23 DBV 5 3000 203.0 203.0 35.0
TL431AQDBZRQ1 SOT-23 DBZ 3 3000 203.0 203.0 35.0
TL431BQDBZRQ1 SOT-23 DBZ 3 3000 203.0 203.0 35.0
PACKAGE MATERIALS INFORMATION
www.ti.com 14-Mar-2013
Pack Materials-Page 2