ONSEMI TL431BIPG

TL431, A, B Series,
NCV431A, B
Programmable
Precision References
The TL431, A, B integrated circuits are three−terminal
programmable shunt regulator diodes. These monolithic IC voltage
references operate as a low temperature coefficient zener which is
programmable from Vref to 36 V with two external resistors. These
devices exhibit a wide operating current range of 1.0 mA to 100 mA
with a typical dynamic impedance of 0.22 W. The characteristics of
these references make them excellent replacements for zener diodes in
many applications such as digital voltmeters, power supplies, and op
amp circuitry. The 2.5 V reference makes it convenient to obtain a
stable reference from 5.0 V logic supplies, and since the TL431, A, B
operates as a shunt regulator, it can be used as either a positive or
negative voltage reference.
Features
•
•
•
•
•
•
•
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TO−92 (TO−226)
LP SUFFIX
CASE 29
1
2
Pin 1. Reference
2. Anode
3. Cathode
3
PDIP−8
P SUFFIX
CASE 626
8
Programmable Output Voltage to 36 V
Voltage Reference Tolerance: ±0.4%, Typ @ 25°C (TL431B)
Low Dynamic Output Impedance, 0.22 W Typical
Sink Current Capability of 1.0 mA to 100 mA
Equivalent Full−Range Temperature Coefficient of 50 ppm/°C Typical
Temperature Compensated for Operation over Full Rated Operating
Temperature Range
Low Output Noise Voltage
These are Pb−Free and Halide−Free Devices
1
Micro8E
DM SUFFIX
CASE 846A
8
1
Cathode 1
8 Reference
N/C 2
7 N/C
N/C 3
6 Anode
N/C 4
5 N/C
(Top View)
SOIC−8
D SUFFIX
CASE 751
8
1
Cathode 1
8
2
7
3
6
N/C 4
5
Anode
Reference
Anode
N/C
(Top View)
This is an internally modified SOIC−8 package. Pins 2, 3, 6 and
7 are electrically common to the die attach flag. This internal
lead frame modification increases power dissipation capability
when appropriately mounted on a printed circuit board. This
modified package conforms to all external dimensions of the
standard SOIC−8 package.
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 13 of this data sheet.
DEVICE MARKING INFORMATION
See general marking information in the device marking
section on page 14 of this data sheet.
© Semiconductor Components Industries, LLC, 2012
April, 2012 − Rev. 34
1
Publication Order Number:
TL431/D
TL431, A, B Series, NCV431A, B
Symbol
Representative Schematic Diagram
Component values are nominal
Cathode
(K)
Cathode (K)
Reference
(R)
800
800
Reference
(R)
Anode
(A)
20 pF
Representative Block Diagram
Reference
(R)
4.0 k
20 pF
Cathode
(K)
+
150
3.28 k
2.4 k
10 k
7.2 k
1.0 k
2.5 Vref
800
Anode (A)
Anode (A)
This device contains 12 active transistors.
MAXIMUM RATINGS (Full operating ambient temperature range applies, unless otherwise noted.)
Symbol
Value
Unit
VKA
37
V
Cathode Current Range, Continuous
IK
−100 to +150
mA
Reference Input Current Range, Continuous
Iref
−0.05 to +10
mA
Operating Junction Temperature
TJ
150
°C
Operating Ambient Temperature Range
TL431I, TL431AI, TL431BI
TL431C, TL431AC, TL431BC
NCV431AI, NCV431B, TL431BV
TA
Storage Temperature Range
Tstg
Total Power Dissipation @ TA = 25°C
Derate above 25°C Ambient Temperature
D, LP Suffix Plastic Package
P Suffix Plastic Package
DM Suffix Plastic Package
PD
Total Power Dissipation @ TC = 25°C
Derate above 25°C Case Temperature
D, LP Suffix Plastic Package
P Suffix Plastic Package
PD
Rating
Cathode to Anode Voltage
°C
−40 to +85
0 to +70
−40 to +125
−65 to +150
°C
W
0.70
1.10
0.52
W
1.5
3.0
ESD Rating
HBM
MM
>2000
>200
V
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
RECOMMENDED OPERATING CONDITIONS
Condition
Cathode to Anode Voltage
Cathode Current
Symbol
Min
Max
Unit
VKA
Vref
36
V
IK
1.0
100
mA
THERMAL CHARACTERISTICS
Symbol
D, LP Suffix
Package
P Suffix
Package
DM Suffix
Package
Unit
Thermal Resistance, Junction−to−Ambient
RqJA
178
114
240
°C/W
Thermal Resistance, Junction−to−Case
RqJC
83
41
−
°C/W
Characteristic
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2
TL431, A, B Series, NCV431A, B
ELECTRICAL CHARACTERISTICS (TA = 25°C, unless otherwise noted.)
TL431I
Min
Symbol
Characteristic
Reference Input Voltage (Figure 1)
VKA = Vref, IK = 10 mA
TA = 25°C
TA = Tlow to Thigh (Note 1)
TL431C
Typ
Max
Min
Typ
Max
Vref
Reference Input Voltage Deviation Over
Temperature Range (Figure 1, Notes 1, 2)
VKA= Vref, IK = 10 mA
V
2.44
2.41
2.495
−
2.55
2.58
2.44
2.423
2.495
−
2.55
2.567
−
7.0
30
−
3.0
17
DVref
Ratio of Change in Reference Input Voltage to Change
in Cathode to Anode Voltage
IK = 10 mA (Figure 2),
DVKA = 10 V to Vref
DVKA = 36 V to 10 V
DV
DV
Reference Input Current (Figure 2)
IK = 10 mA, R1 = 10 k, R2 = ∞
TA = 25°C
TA = Tlow to Thigh (Note 1)
Unit
mV
mV/V
ref
KA
−
−
−1.4
−1.0
−2.7
−2.0
−
−
−1.4
−1.0
−2.7
−2.0
Iref
mA
−
−
1.8
−
4.0
6.5
−
−
1.8
−
4.0
5.2
Reference Input Current Deviation Over
Temperature Range (Figure 2, Note 1, 4)
IK = 10 mA, R1 = 10 k, R2 = ∞
DIref
−
0.8
2.5
−
0.4
1.2
mA
Minimum Cathode Current For Regulation
VKA = Vref (Figure 1)
Imin
−
0.5
1.0
−
0.5
1.0
mA
Off−State Cathode Current (Figure 3)
VKA = 36 V, Vref = 0 V
Ioff
−
20
1000
−
20
1000
nA
|ZKA|
−
0.22
0.5
−
0.22
0.5
W
Dynamic Impedance (Figure 1, Note 3)
VKA = Vref, DIK = 1.0 mA to 100 mA
f ≤ 1.0 kHz
1. Tlow
= −40°C for TL431AIP TL431AILP, TL431IP, TL431ILP, TL431BID, TL431BIP, TL431BILP, TL431AIDM, TL431IDM, TL431BIDM;
= 0°C for TL431ACP, TL431ACLP, TL431CP, TL431CLP, TL431CD, TL431ACD, TL431BCD, TL431BCP, TL431BCLP, TL431CDM,
TL431ACDM, TL431BCDM
Thigh = +85°C for TL431AIP, TL431AILP, TL431IP, TL431ILP, TL431BID, TL431BIP, TL431BILP, TL431IDM, TL431AIDM, TL431BIDM
= +70°C for TL431ACP, TL431ACLP, TL431CP, TL431ACD, TL431BCD, TL431BCP, TL431BCLP, TL431CDM, TL431ACDM,
TL431BCDM
2. The deviation parameter DVref is defined as the difference between the maximum and minimum values obtained over the full operating
ambient temperature range that applies.
Vref max
DVref = Vref max
-Vref min
DTA = T2 - T1
Vref min
T1
Ambient Temperature
T2
The average temperature coefficient of the reference input voltage, aVref is defined as:
ppm
V
+
ref _C
ǒ
Ǔ
DV
V
ref
ref
@ 25_C
DT
A
X 106
+
D V x 10 6
ref
D T (V @ 25_C)
A ref
aVref can be positive or negative depending on whether Vref Min or Vref Max occurs at the lower ambient temperature. (Refer to Figure 6.)
Example : DV
V
ref
+ 8.0 mV and slope is positive,
@ 25_C + 2.495 V, DT + 70_C
ref
A
aV
ref
+
0.008 x 106
+ 45.8 ppmń_C
70 (2.495)
DV
KA
3. The dynamic impedance ZKA is defined as: |Z KA| +
. When the device is programmed with two external resistors, R1 and R2,
DI
K
ǒ
(refer to Figure 2) the total dynamic impedance of the circuit is defined as: |Z KAȀ| [ |Z KA| 1 ) R1
R2
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3
Ǔ
TL431, A, B Series, NCV431A, B
ELECTRICAL CHARACTERISTICS (TA = 25°C, unless otherwise noted.)
TL431AI / NCV431AI
Characteristic
Symbol
Reference Input Voltage (Figure 1)
VKA = Vref, IK = 10 mA
TA = 25°C
TA = Tlow to Thigh
Min
Typ
Max
TL431BC / TL431BI /
TL431BV /
NCV431BV
TL431AC
Min
Typ
Max
Min
Typ
Max
Unit
Vref
Reference Input Voltage Deviation Over
Temperature Range (Figure 1, Notes 4, 5)
VKA= Vref, IK = 10 mA
DVref
Ratio of Change in Reference Input Voltage to
Change in Cathode to Anode Voltage
IK = 10 mA (Figure 2),
DVKA = 10 V to Vref
DVKA = 36 V to 10 V
DV
DV
Reference Input Current (Figure 2)
IK = 10 mA, R1 = 10 k, R2 = ∞
TA = 25°C
TA = Tlow to Thigh (Note 4)
V
2.47
2.44
2.495
−
2.52
2.55
2.47
2.453
2.495
−
2.52
2.537
2.485
2.475
2.495
2.495
2.505
2.515
−
7.0
30
−
3.0
17
−
3.0
17
mV/V
ref
KA
mV
−
−
−1.4
−1.0
−2.7
−2.0
−
−
−1.4
−1.0
−2.7
−2.0
−
−
−1.4
−1.0
−2.7
−2.0
Iref
mA
−
−
1.8
−
4.0
6.5
−
−
1.8
−
4.0
5.2
−
−
1.1
−
2.0
4.0
Reference Input Current Deviation Over
Temperature Range (Figure 2, Note 4)
IK = 10 mA, R1 = 10 k, R2 = ∞
DIref
−
0.8
2.5
−
0.4
1.2
−
0.8
2.5
mA
Minimum Cathode Current For Regulation
VKA = Vref (Figure 1)
Imin
−
0.5
1.0
−
0.5
1.0
−
0.5
1.0
mA
Off−State Cathode Current (Figure 3)
VKA = 36 V, Vref = 0 V
Ioff
−
20
1000
−
20
1000
−
0.23
500
nA
|ZKA|
−
0.22
0.5
−
0.22
0.5
−
0.14
0.3
W
Dynamic Impedance (Figure 1, Note 6)
VKA = Vref, DIK = 1.0 mA to 100 mA
f ≤ 1.0 kHz
4. Tlow
= −40°C for TL431AIP TL431AILP, TL431IP, TL431ILP, TL431BID, TL431BIP, TL431BILP, TL431BV, TL431AIDM, TL431IDM,
TL431BIDM, NCV431AIDMR2G, NCV431AIDR2G, NCV431BVDR2G
= 0°C for TL431ACP, TL431ACLP, TL431CP, TL431CLP, TL431CD, TL431ACD, TL431BCD, TL431BCP, TL431BCLP, TL431CDM,
TL431ACDM, TL431BCDM
Thigh = +85°C for TL431AIP, TL431AILP, TL431IP, TL431ILP, TL431BID, TL431BIP, TL431BILP, TL431IDM, TL431AIDM, TL431BIDM
= +70°C for TL431ACP, TL431ACLP, TL431CP, TL431ACD, TL431BCD, TL431BCP, TL431BCLP, TL431CDM, TL431ACDM,
TL431BCDM
= +125°C TL431BV, NCV431AIDMR2G, NCV431AIDR2G, NCV431BVDMR2G, NCV431BVDR2G
5. The deviation parameter DVref is defined as the difference between the maximum and minimum values obtained over the full operating
ambient temperature range that applies.
Vref max
DVref = Vref max
-Vref min
DTA = T2 - T1
Vref min
T1
Ambient Temperature
T2
The average temperature coefficient of the reference input voltage, aVref is defined as:
ppm
V
+
ref _C
ǒ
Ǔ
DV
V
ref
ref
@ 25_C
DT
A
X 106
+
x 10 6
ref
D T (V @ 25_C)
A ref
DV
aVref can be positive or negative depending on whether Vref Min or Vref Max occurs at the lower ambient temperature. (Refer to Figure 6.)
Example : DV
V
ref
+ 8.0 mV and slope is positive,
@ 25_C + 2.495 V, DT + 70_C
ref
A
aV
ref
+
0.008 x 106
+ 45.8 ppmń_C
70 (2.495)
DV
KA
6. The dynamic impedance ZKA is defined as |Z KA| +
When the device is programmed with two external resistors, R1 and R2, (refer
DI
K
ǒ
Ǔ
to Figure 2) the total dynamic impedance of the circuit is defined as: |Z KAȀ| [ |Z KA| 1 ) R1
R2
7. NCV431AIDMR2G, NCV431AIDR2G, NCV431BVDMR2G, NCV431BVDR2G Tlow = −40°C, Thigh = +125°C. Guaranteed by design.
NCV prefix is for automotive and other applications requiring unique site and control change requirements.
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TL431, A, B Series, NCV431A, B
Input
Input
VKA
IK
VKA
Iref
R1
Vref
Input
Ioff
IK
R2
V
KA
+V
ǒ
VKA
Ǔ
1 ) R1 ) I SR1
ref
R2
ref
Vref
Figure 1. Test Circuit for VKA = Vref
Figure 2. Test Circuit for VKA > Vref
800
VKA = Vref
TA = 25°C
100
Input
IK
IK , CATHODE CURRENT ( μA)
IK , CATHODE CURRENT (mA)
150
Figure 3. Test Circuit for Ioff
VKA
50
0
-50
-100
-2.0
-1.0
0
1.0
2.0
VKA = Vref
TA = 25°C
600 Input
400
200
0
-200
-1.0
3.0
0
Vref , REFERENCE INPUT VOLTAGE (mV)
VKA
IK VKA = Vref
IK = 10 mA
Input
2560
Vref
Vref Max = 2550 mV
2540
2520
Vref Typ = 2495 mV
2500
2480
2460
2440
Vref Min = 2440 mV
2420
2400
-55
-25
0
25
50
2.0
3.0
Figure 5. Cathode Current versus
Cathode Voltage
Iref , REFERENCE INPUT CURRENT ( μA)
Figure 4. Cathode Current versus
Cathode Voltage
2580
1.0
VKA, CATHODE VOLTAGE (V)
VKA, CATHODE VOLTAGE (V)
2600
IMin
VKA
IK
75
100
125
3.0
2.5
2.0
1.5
IK = 10 mA
1.0
VKA
Input
10k Iref
IK
0.5
0
-55
-25
0
25
50
75
100
TA, AMBIENT TEMPERATURE (°C)
TA, AMBIENT TEMPERATURE (°C)
Figure 6. Reference Input Voltage versus
Ambient Temperature
Figure 7. Reference Input Current versus
Ambient Temperature
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5
125
0
IK = 10 mA
TA = 25°C
-8.0
-16
Input
VKA
IK
R1
-24
-32
R2
Vref
0
10
30
20
1.0 k
Ioff , OFF-STATE CATHODE CURRENT (nA)
Δ Vref , REFERENCE INPUT VOLTAGE (mV)
TL431, A, B Series, NCV431A, B
100
10
1.0
Input
0.01
-55
40
-25
+
GND
1.0
0.1
1.0 k
10 k
100 k
1.0 M
0.280
0.260
75
100
125
0.240
0.220
0.200
-55
10 M
-25
0
25
50
75
100
125
TA, AMBIENT TEMPERATURE (°C)
Figure 10. Dynamic Impedance
versus Frequency
Figure 11. Dynamic Impedance
versus Ambient Temperature
80
60
50
9.0 mF
40
Output
IK
15k
230
NOISE VOLTAGE (nV/ √Hz)
A VOL, OPEN LOOP VOLTAGE GAIN (dB)
50
VKA = Vref
D IK = 1.0 mA to 100 mA
f ≤ 1.0 kHz
Output
1.0k
IK
50
+
GND
0.300
f, FREQUENCY (MHz)
8.25k
GND
30
20
10
25
0.320
TA = 25°C
D IK = 1.0 mA to 100 mA
|ZKA|, DYNAMIC IMPEDANCE (Ω )
|ZKA|, DYNAMIC IMPEDANCE (Ω )
10
0
Figure 9. Off−State Cathode Current
versus Ambient Temperature
100
50
VKA
TA, AMBIENT TEMPERATURE (5C)
Figure 8. Change in Reference Input
Voltage versus Cathode Voltage
Output
IK
Ioff
0.1
VKA, CATHODE VOLTAGE (V)
1.0 k
VKA = 36 V
Vref = 0 V
IK = 10 mA
TA = 25°C
60
VKA = Vref
IK = 10 mA
TA = 25°C
40
Input
20
Output
IK
0
-10
1.0 k
10 k
100 k
1.0 M
0
10
10 M
100
1.0 k
10 k
f, FREQUENCY (Hz)
f, FREQUENCY (MHz)
Figure 12. Open−Loop Voltage Gain
versus Frequency
Figure 13. Spectral Noise Density
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100 k
TL431, A, B Series, NCV431A, B
Input
Monitor
Output
2.0
220 Output
Pulse
Generator
f = 100 kHz
1.0
50
GND
0
5.0
Input
0
0
4.0
12
8.0
16
Unstable
Area
A
B
C
D
120
I K, CATHODE CURRENT (mA)
VOLTAGE SWING (V)
140
TA = 25°C
3.0
100
TA = 25°C
C
80
60
Stable
40
Stable
D
B
B
A
20
0
1.0 nF
20
Programmed
VKA(V)
Vref
5.0
10
15
10 nF
t, TIME (ms)
A
100 nF
1.0 mF
10 mF
100 mF
CL, LOAD CAPACITANCE
Figure 14. Pulse Response
Figure 15. Stability Boundary Conditions
150
150
IK
IK
V+
10 k
V+
CL
Figure 16. Test Circuit For Curve A
of Stability Boundary Conditions
CL
Figure 17. Test Circuit For Curves B, C, And D
of Stability Boundary Conditions
TYPICAL APPLICATIONS
V+
V+
Vout
Vout
R1
R1
R2
R2
ǒ
Ǔ
V out + 1 ) R1 V
R2 ref
ǒ
Ǔ
V out + 1 ) R1 V
R2 ref
Figure 18. Shunt Regulator
Figure 19. High Current Shunt Regulator
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TL431, A, B Series, NCV431A, B
V+
V+
MC7805
Out
In
Common
Vout
R1
Vout
R1
R2
R2
ǒ
ǒ
V
out(min)
Ǔ
+V
ref
V
) 5.0V
Figure 20. Output Control for a
Three−Terminal Fixed Regulator
RCL
V+
Ǔ
V out + 1 ) R1 V
R2 ref
V out + 1 ) R1 V
R2 ref
in(min)
+ V out ) V
V
+V
out(min)
be
ref
Figure 21. Series Pass Regulator
V+
Iout
Isink
I
V
I out + ref
R
CL
Sink
V
+ ref
R
S
RS
Figure 22. Constant Current Source
V+
Figure 23. Constant Current Sink
V+
Vout
Vout
R1
R1
R2
ǒ
R2
Ǔ
V
+ 1 ) R1 V
out(trip)
R2 ref
V
Figure 24. TRIAC Crowbar
out(trip)
ǒ
Ǔ
+ 1 ) R1 V
R2 ref
Figure 25. SRC Crowbar
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TL431, A, B Series, NCV431A, B
V+
Vout
l
R1
V+
R3
Vout
Vin
R2
R4
Vin
Vth = Vref
L.E.D. indicator is `on' when V+ is between the
upper and lower limits.
ǒ Ǔ
UpperLimit + ǒ1 ) R3ǓV
R4 ref
LowerLimit + 1 ) R1 V
R2 ref
Figure 26. Voltage Monitor
5.0 k
1%
50 k
1%
10 kW
V
500 k
1%
5.0 M
1%
100 kW
1.0 MW
V
V
Range
1.0 kW
V
RX
V+
> Vref
≈ 2.0 V
Figure 27. Single−Supply Comparator with
Temperature−Compensated Threshold
25 V
1N5305
Vout
< Vref
38 V
2.0 mA
TI
10 k
Calibrate
25 V
LM11
+
330
Tl = 330 to 8.0 W
8.0 W
+
470 mF
360 k
1.0 mF
*
Vout
* Thermalloy
* THM 6024
* Heatsink on
* LP Package
-5.0 V
W
R x + V outD Range
V
Figure 28. Linear Ohmmeter
56 k
10 k
0.05 mF
Tone
25 k
Volume
47 k
Figure 29. Simple 400 mW Phono Amplifier
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TL431, A, B Series, NCV431A, B
150 mH @ 2.0 A
Vin = 10 V to 20 V
TIP115
Vout = 5.0 V
Iout = 1.0 A
1.0 k
4.7 k
+
4.7 k
MPSA20
2200 mF
1N5823
100 k
0.01mF
470 mF
4.7 k
0.1 mF
2.2 k
10
51 k
Figure 30. High Efficiency Step−Down Switching Converter
Test
Conditions
Results
Line Regulation
Vin = 10 V to 20 V, Io = 1.0 A
53 mV (1.1%)
Load Regulation
Vin = 15 V, Io = 0 A to 1.0 A
25 mV (0.5%)
Output Ripple
Vin = 10 V, Io = 1.0 A
50 mVpp P.A.R.D.
Output Ripple
Vin = 20 V, Io = 1.0 A
100 mVpp P.A.R.D.
Efficiency
Vin = 15 V, Io = 1.0 A
82%
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+
TL431, A, B Series, NCV431A, B
APPLICATIONS INFORMATION
The TL431 is a programmable precision reference which
is used in a variety of ways. It serves as a reference voltage
in circuits where a non−standard reference voltage is
needed. Other uses include feedback control for driving an
optocoupler in power supplies, voltage monitor, constant
current source, constant current sink and series pass
regulator. In each of these applications, it is critical to
maintain stability of the device at various operating currents
and load capacitances. In some cases the circuit designer can
estimate the stabilization capacitance from the stability
boundary conditions curve provided in Figure 15. However,
these typical curves only provide stability information at
specific cathode voltages and at a specific load condition.
Additional information is needed to determine the
capacitance needed to optimize phase margin or allow for
process variation.
A simplified model of the TL431 is shown in Figure 31.
When tested for stability boundaries, the load resistance is
150 W. The model reference input consists of an input
transistor and a dc emitter resistance connected to the device
anode. A dependent current source, Gm, develops a current
whose amplitude is determined by the difference between
the 1.78 V internal reference voltage source and the input
transistor emitter voltage. A portion of Gm flows through
compensation capacitance, CP2. The voltage across CP2
drives the output dependent current source, Go, which is
connected across the device cathode and anode.
P2 +
Z1 +
Example 1:
C
P1
+
G+G R
GoR
M GM
L
I + 10 mA, R + 230 W, C + 0. Define the transfer gain.
L
L
C
The DC gain is:
G+G R
GoR +
M GM
L
(2.138)(1.0 M)(1.25 m)(230) + 615 + 56 dB
Loop gain + G
8.25 k
+ 218 + 47 dB
8.25 k ) 15 k
The resulting transfer function Bode plot is shown in
Figure 32. The asymptotic plot may be expressed as the
following equation:
ǒ1 ) 500jfkHzǓ
Av + 615
ǒ1 ) 8.0jfkHzǓǒ1 ) 60 jfkHzǓ
Resistor and capacitor typical values are shown on the
model. Process tolerances are ± 20% for resistors, ±10% for
capacitors, and ±40% for transconductances.
An examination of the device model reveals the location
of circuit poles and zeroes:
1
1
1
+
+ 500 kHz
2p * 15.9 k * 20 pF
C
Z1 P1
Also, the transfer dc voltage gain of the TL431 is:
Go = 1.25 (Vcp2) mmhos.
GM
2p R
1
P +
L
2p R C
L L
where IC is the device cathode current and Gm is in mhos
2p R
1
1
+
+ 60 kHz
2p * 10 M * 0.265 pF
C
P2 P2
In addition, there is an external circuit pole defined by the
load:
Model component values are:
Vref = 1.78 V
Gm = 0.3 + 2.7 exp (−IC/26 mA)
P1 +
2p R
The Bode plot shows a unity gain crossover frequency of
approximately 600 kHz. The phase margin, calculated from
the equation, would be 55.9 degrees. This model matches the
Open−Loop Bode Plot of Figure 12. The total loop would
have a unity gain frequency of about 300 kHz with a phase
margin of about 44 degrees.
1
+ 7.96 kHz
2p * 1.0 M * 20 pF
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11
TL431, A, B Series, NCV431A, B
VCC
RL
CL
Input
3
15 k
Cathode
9.0 mF
Ref
RP2
10 M
Vref
1.78 V
1
500 k
CP1
20 pF
GM
+
-
Rref
RGM
1.0 M
16
RZ1
15.9 k
8.25 k
Anode
Go
1.0 mmho
CP2
0.265 pF
2
Figure 31. Simplified TL431 Device Model
Note that the transfer function now has an extra pole
formed by the load capacitance and load resistance.
Note that the crossover frequency in this case is about
250 kHz, having a phase margin of about −46 degrees.
Therefore, instability of this circuit is likely.
TL431 OPEN-LOOP VOLTAGE GAIN VERSUS FREQUENCY
50
40
30
TL431 OPEN-LOOP BODE PLOT WITH LOAD CAP
20
80
10
Av, OPEN-LOOP GAIN (dB)
Av, OPEN-LOOP VOLTAGE GAIN (dB)
60
0
-10
-20
101
102
103
104
105
106
107
f, FREQUENCY (Hz)
Figure 32. Example 1 Circuit Open Loop Gain Plot
Example 2.
IC = 7.5 mA, RL = 2.2 kW, CL = 0.01 mF. Cathode tied to
reference input pin. An examination of the data sheet
stability boundary curve (Figure 15) shows that this value of
load capacitance and cathode current is on the boundary.
Define the transfer gain.
The DC gain is:
60
40
20
0
-20
101
102
103
104
105
106
f, FREQUENCY (Hz)
Figure 33. Example 2 Circuit Open Loop Gain Plot
With three poles, this system is unstable. The only hope
for stabilizing this circuit is to add a zero. However, that can
only be done by adding a series resistance to the output
capacitance, which will reduce its effectiveness as a noise
filter. Therefore, practically, in reference voltage
applications, the best solution appears to be to use a smaller
value of capacitance in low noise applications or a very
large value to provide noise filtering and a dominant pole
rolloff of the system.
G+G R
GoR +
M GM
L
(2.323)(1.0 M)(1.25 m)(2200) + 6389 + 76 dB
The resulting open loop Bode plot is shown in Figure 33.
The asymptotic plot may be expressed as the following
equation:
ǒ1 ) 500jfkHzǓ
Av + 615
ǒ1 ) 8.0jfkHzǓǒ1 ) 60 jfkHzǓǒ1 ) 7.2jfkHzǓ
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12
TL431, A, B Series, NCV431A, B
ORDERING INFORMATION
Device
Marking
Code
TL431ACDG
AC
TL431BCDG
BC
TL431CDG
AC
TL431BCDR2G
BC
C
TL431ACDMR2G
TAC
TL431BCDMR2G
TBC
TL431CDMR2G
T−C
TL431ACPG
ACP
TL431BCPG
BCP
TL431CPG
CP
TL431ACLPG
ACLP
TL431BCLPG
BCLP
TL431CLPG
Package Code
C
TL431ACDR2G
TL431CDR2G
Operating Temperature Range
0°C to 70°C
CLP
Shipping Information†
Tolerance
1.0%
SOIC−8
(Pb−Free)
98 Units / Rail
SOIC−8
(Pb−Free)
2500 Units / Tape & Reel
Micro8
(Pb−Free)
4000 Units / Tape & Reel
0.4%
2.2%
1.0%
0.4%
2.2%
1.0%
0.4%
2.2%
1.0%
PDIP−8
(Pb−Free)
50 Units / Rail
TO−92
(Pb−Free)
2000 Units / Bag
0.4%
2.2%
1.0%
0.4%
2.2%
TL431ACLPRAG
ACLP
1.0%
TL431BCLPRAG
BCLP
0.4%
TL431CLPRAG
CLP
TL431ACLPREG
ACLP
TL431BCLPREG
BCLP
TL431CLPREG
TL431ACLPRPG
TL431BCLPRMG
CLP
TL431AIDG
AI
TL431BIDG
BI
I
TL431AIDR2G
AI
TL431BIDR2G
BI
I
TL431AIDMR2G
TAI
TL431BIDMR2G
TBI
TL431IDMR2G
T−I
TL431AIPG
AIP
TL431BIPG
BIP
TL431IPG
IP
TL431AILPG
AILP
TL431BILPG
BILP
TL431ILPG
AILP
TL431BILPRAG
BILP
SC431ILPRAG
ILP
TL431ILPRAG
ILP
TL431AILPRMG
TL431AILPRPG
TL431ILPRPG
−40°C to 85°C
2000 / Tape & Ammo Box
1.0%
0.4%
TO−92
(Pb−Free)
2000 Units / Fan−Fold
SOIC−8
(Pb−Free)
98 Units / Rail
SOIC−8
(Pb−Free)
2500 Units / Tape & Reel
Micro8
(Pb−Free)
4000 Units / Tape & Reel
PDIP−8
(Pb−Free)
50 Units / Rail
TO−92
(Pb−Free)
ILP
TL431AILPRAG
1.0%
2.2%
TO−92
(Pb−Free)
BCLP
CLP
2.2%
0.4%
ACLP
TL431CLPRPG
TL431IDR2G
2000 Units / Tape & Reel
CLP
TL431CLPRMG
TL431IDG
TO−92
(Pb−Free)
2.2%
2.2%
1.0%
0.4%
2.2%
1.0%
0.4%
2.2%
1.0%
0.4%
2.2%
1.0%
0.4%
2.2%
1.0%
2000 Units / Bag
0.4%
2.2%
1.0%
TO−92
(Pb−Free)
2000 Units / Tape & Reel
0.4%
2.2%
2.2%
AILP
TO−92
(Pb−Free)
ILP
1.0%
2000 / Tape & Ammo Box
1.0%
2.2%
†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging
Specifications Brochure, BRD8011/D.
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13
TL431, A, B Series, NCV431A, B
ORDERING INFORMATION
Device
TL431BVDG
TL431BVDR2G
TL431BVDMR2G
TL431BVLPG
TL431BVLPRAG
TL431BVPG
NCV431AIDMR2G
NCV431AIDR2G
NCV431BVDMR2G
NCV431BVDR2G
Marking
Code
Operating Temperature Range
Package Code
BV
SOIC−8
(Pb−Free)
TBV
Micro8
(Pb−Free)
BVLP
TO−92
(Pb−Free)
BVP
Shipping Information†
98 Units / Rail
Tolerance
0.4%
2500 Units / Tape & Reel
0.4%
4000 Units / Tape & Reel
0.4%
2000 Units / Bag
0.4%
2000 Units / Tape & Reel
0.4%
PDIP−8
(Pb−Free)
50 Units / Rail
0.4%
RAN
Micro8
(Pb−Free)
4000 Units / Tape & Reel
1%
AV
SOIC−8
(Pb−Free)
2500 Units / Tape & Reel
1%
NVB
Micro8
(Pb−Free)
4000 Units / Tape & Reel
0.4%
BV
SOIC−8
(Pb−Free)
2500 Units / Tape & Reel
0.4%
−40°C to 125°C
†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging
Specifications Brochure, BRD8011/D.
MARKING DIAGRAMS
SOIC−8
D SUFFIX
CASE 751
8
Micro8
CASE 846A
PDIP−8
CASE 626
8
8
431xx
ALYW
G
1
TL431xxx
AWL
YYWWG
xxx
AYWG
G
1
8
TL431
ALYWx
G
1
(Exception for the TL431CD
and TL431ID only)
TO−92 (TO−226)
CASE 29
1
xxxx
= See Specific Marking Code
A
= Assembly Location
Y, YY
= Year
WW, W = Work Week
G or G
= Pb−Free Package
(Note: Microdot may be in either location)
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14
TL431
xxxx
YWW G
G
TL431, A, B Series, NCV431A, B
PACKAGE DIMENSIONS
TO−92 (TO−226)
CASE 29−11
ISSUE AM
1
12
3
STRAIGHT LEAD
BULK PACK
2
3
BENT LEAD
TAPE & REEL
AMMO PACK
A
B
STRAIGHT LEAD
BULK PACK
R
P
L
SEATING
PLANE
K
D
X X
G
J
H
V
C
SECTION X−X
N
1
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. CONTOUR OF PACKAGE BEYOND DIMENSION R
IS UNCONTROLLED.
4. LEAD DIMENSION IS UNCONTROLLED IN P AND
BEYOND DIMENSION K MINIMUM.
DIM
A
B
C
D
G
H
J
K
L
N
P
R
V
INCHES
MIN
MAX
0.175
0.205
0.170
0.210
0.125
0.165
0.016
0.021
0.045
0.055
0.095
0.105
0.015
0.020
0.500
--0.250
--0.080
0.105
--0.100
0.115
--0.135
---
MILLIMETERS
MIN
MAX
4.45
5.20
4.32
5.33
3.18
4.19
0.407
0.533
1.15
1.39
2.42
2.66
0.39
0.50
12.70
--6.35
--2.04
2.66
--2.54
2.93
--3.43
---
N
A
R
BENT LEAD
TAPE & REEL
AMMO PACK
B
P
T
SEATING
PLANE
G
K
D
X X
J
V
1
C
N
SECTION X−X
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15
NOTES:
1. DIMENSIONING AND TOLERANCING PER
ASME Y14.5M, 1994.
2. CONTROLLING DIMENSION: MILLIMETERS.
3. CONTOUR OF PACKAGE BEYOND
DIMENSION R IS UNCONTROLLED.
4. LEAD DIMENSION IS UNCONTROLLED IN P
AND BEYOND DIMENSION K MINIMUM.
DIM
A
B
C
D
G
J
K
N
P
R
V
MILLIMETERS
MIN
MAX
4.45
5.20
4.32
5.33
3.18
4.19
0.40
0.54
2.40
2.80
0.39
0.50
12.70
--2.04
2.66
1.50
4.00
2.93
--3.43
---
TL431, A, B Series, NCV431A, B
PACKAGE DIMENSIONS
PDIP−8
P SUFFIX
CASE 626−05
ISSUE M
D
A
D1
E
8
5
E1
1
4
NOTE 5
F
c
E2
END VIEW
TOP VIEW
NOTE 3
e/2
A
L
A1
C
SEATING
PLANE
E3
e
8X
SIDE VIEW
b
0.010
M
C A
END VIEW
http://onsemi.com
16
NOTES:
1. DIMENSIONING AND TOLERANCING PER ASME
Y14.5M, 1994.
2. CONTROLLING DIMENSION: INCHES.
3. DIMENSION E IS MEASURED WITH THE LEADS RESTRAINED PARALLEL AT WIDTH E2.
4. DIMENSION E1 DOES NOT INCLUDE MOLD FLASH.
5. ROUNDED CORNERS OPTIONAL.
DIM
A
A1
b
C
D
D1
E
E1
E2
E3
e
L
INCHES
NOM
MAX
−−−− 0.210
−−−− −−−−
0.018 0.022
0.010 0.014
0.365 0.400
−−−− −−−−
0.310 0.325
0.250 0.280
0.300 BSC
−−−−
−−−− 0.430
0.100 BSC
0.115 0.130 0.150
MIN
−−−−
0.015
0.014
0.008
0.355
0.005
0.300
0.240
MILLIMETERS
MIN
NOM
MAX
−−−−
−−−−
5.33
0.38
−−−− −−−−
0.35
0.46
0.56
0.20
0.25
0.36
9.02
9.27 10.02
0.13
−−−− −−−−
7.62
7.87
8.26
6.10
6.35
7.11
7.62 BSC
−−−−
−−−− 10.92
2.54 BSC
2.92
3.30
3.81
TL431, A, B Series, NCV431A, B
PACKAGE DIMENSIONS
Micro8
DM SUFFIX
CASE 846A−02
ISSUE G
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETER.
3. DIMENSION A DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE
BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED
0.15 (0.006) PER SIDE.
4. DIMENSION B DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSION.
INTERLEAD FLASH OR PROTRUSION SHALL NOT EXCEED 0.25 (0.010) PER SIDE.
5. 846A-01 OBSOLETE, NEW STANDARD 846A-02.
D
HE
PIN 1 ID
E
e
b 8 PL
0.08 (0.003)
T B
M
S
A
DIM
A
A1
b
c
D
E
e
L
HE
S
SEATING
−T− PLANE
0.038 (0.0015)
MILLIMETERS
NOM
MAX
−−
1.10
0.08
0.15
0.33
0.40
0.18
0.23
3.00
3.10
3.00
3.10
0.65 BSC
0.40
0.55
0.70
4.75
4.90
5.05
MIN
−−
0.05
0.25
0.13
2.90
2.90
A
A1
L
c
SOLDERING FOOTPRINT*
8X
1.04
0.041
0.38
0.015
3.20
0.126
6X
8X
4.24
0.167
0.65
0.0256
5.28
0.208
SCALE 8:1
mm Ǔ
ǒinches
*For additional information on our Pb−Free strategy and soldering
details, please download the ON Semiconductor Soldering and
Mounting Techniques Reference Manual, SOLDERRM/D.
http://onsemi.com
17
INCHES
NOM
−−
0.003
0.013
0.007
0.118
0.118
0.026 BSC
0.016
0.021
0.187
0.193
MIN
−−
0.002
0.010
0.005
0.114
0.114
MAX
0.043
0.006
0.016
0.009
0.122
0.122
0.028
0.199
TL431, A, B Series, NCV431A, B
PACKAGE DIMENSIONS
SOIC−8
D SUFFIX
CASE 751−07
ISSUE AK
−X−
NOTES:
1. DIMENSIONING AND TOLERANCING PER
ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETER.
3. DIMENSION A AND B DO NOT INCLUDE
MOLD PROTRUSION.
4. MAXIMUM MOLD PROTRUSION 0.15 (0.006)
PER SIDE.
5. DIMENSION D DOES NOT INCLUDE DAMBAR
PROTRUSION. ALLOWABLE DAMBAR
PROTRUSION SHALL BE 0.127 (0.005) TOTAL
IN EXCESS OF THE D DIMENSION AT
MAXIMUM MATERIAL CONDITION.
6. 751−01 THRU 751−06 ARE OBSOLETE. NEW
STANDARD IS 751−07.
A
8
5
S
B
0.25 (0.010)
M
Y
M
1
4
−Y−
K
G
C
N
DIM
A
B
C
D
G
H
J
K
M
N
S
X 45 _
SEATING
PLANE
−Z−
0.10 (0.004)
H
D
0.25 (0.010)
M
Z Y
S
X
M
J
S
MILLIMETERS
MIN
MAX
4.80
5.00
3.80
4.00
1.35
1.75
0.33
0.51
1.27 BSC
0.10
0.25
0.19
0.25
0.40
1.27
0_
8_
0.25
0.50
5.80
6.20
INCHES
MIN
MAX
0.189
0.197
0.150
0.157
0.053
0.069
0.013
0.020
0.050 BSC
0.004
0.010
0.007
0.010
0.016
0.050
0 _
8 _
0.010
0.020
0.228
0.244
SOLDERING FOOTPRINT*
1.52
0.060
7.0
0.275
4.0
0.155
0.6
0.024
1.270
0.050
SCALE 6:1
mm Ǔ
ǒinches
*For additional information on our Pb−Free strategy and soldering
details, please download the ON Semiconductor Soldering and
Mounting Techniques Reference Manual, SOLDERRM/D.
Micro8 is a trademark of International Rectifier.
ON Semiconductor and
are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice
to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability
arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages.
“Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All
operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights
nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications
intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should
Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates,
and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death
associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal
Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner.
PUBLICATION ORDERING INFORMATION
LITERATURE FULFILLMENT:
Literature Distribution Center for ON Semiconductor
P.O. Box 5163, Denver, Colorado 80217 USA
Phone: 303−675−2175 or 800−344−3860 Toll Free USA/Canada
Fax: 303−675−2176 or 800−344−3867 Toll Free USA/Canada
Email: [email protected]
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Europe, Middle East and Africa Technical Support:
Phone: 421 33 790 2910
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Phone: 81−3−5773−3850
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18
ON Semiconductor Website: www.onsemi.com
Order Literature: http://www.onsemi.com/orderlit
For additional information, please contact your local
Sales Representative
TL431/D