Texas Instruments | TLVH431B-EP Enhanced Plastic 0.5% Low-Voltage Wide-Operating Current Adjustable Precision Shunt Regulator | Datasheet | Texas Instruments TLVH431B-EP Enhanced Plastic 0.5% Low-Voltage Wide-Operating Current Adjustable Precision Shunt Regulator Datasheet

Texas Instruments TLVH431B-EP Enhanced Plastic 0.5% Low-Voltage Wide-Operating Current Adjustable Precision Shunt Regulator Datasheet
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TLVH431B-EP
SLVSFF4 – DECEMBER 2019
TLVH431B-EP Enhanced Plastic 0.5% Low-Voltage Wide-Operating Current
Adjustable Precision Shunt Regulator
1 Features
3 Description
•
•
•
•
The TLVH431B-EP device is a low-voltage, 3terminal, adjustable voltage reference with specified
thermal stability over applicable industrial and
commercial temperature ranges. Output voltage can
be set to any value between VREF (1.24 V) and 18 V
with two external resistors (see Figure 24). This
device operates from a lower voltage (1.24 V) than
the widely used TL431 and TL1431 shunt-regulator
references.
1
•
•
Low-voltage operation: down to 1.24 V
Reference voltage tolerances 0.5% at 25°C
Adjustable output voltage, VO = VREF to 18 V
Wide operating cathode current range:
200 μA to 70 mA
0.25-Ω typical output impedance
Supports defense and aerospace applications:
– Controlled baseline
– Available in extended (–55°C to 125°C)
temperature range
– Extended product life cycle
– Extended product-change notification
– Product traceability
When used with an optocoupler, the TLVH431B-EP
device is ideal for voltage references in isolated
feedback circuits designed for 3-V to 3.3-V switchingmode power supplies. It has a typical output
impedance of 0.25 Ω. Active output circuitry provides
a very sharp turn-on characteristic, making the
TLVH431B-EP device an excellent replacement for
low-voltage Zener diodes in many applications,
including on-board regulation and adjustable power
supplies.
2 Applications
•
•
•
•
•
Adjustable voltage and current referencing
Secondary side regulation in flyback SMPSs
Zener replacement
Voltage monitoring
Comparator with integrated reference
Device Information(1)
PART NUMBER
PACKAGE
TLVH431BMDBZREP SOT-23 (3)
BODY SIZE (NOM)
2.92 mm × 1.30 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Simplified Schematic
VO
Input
IK
VREF
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
TLVH431B-EP
SLVSFF4 – DECEMBER 2019
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Table of Contents
1
2
3
4
5
6
7
8
Features ..................................................................
Applications ...........................................................
Description .............................................................
Revision History.....................................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
2
3
4
6.1
6.2
6.3
6.4
6.5
6.6
4
4
4
4
5
6
Absolute Maximum Ratings ......................................
ESD Ratings..............................................................
Recommended Operating Conditions.......................
Thermal Information ..................................................
Electrical Characteristics...........................................
Typical Characteristics ..............................................
8.4 Device Functional Modes........................................ 14
9
Applications and Implementation ...................... 15
9.1 Application Information............................................ 15
9.2 Typical Applications ................................................ 16
10 Power Supply Recommendations ..................... 20
11 Layout................................................................... 20
11.1 Layout Guidelines ................................................. 20
11.2 Layout Example .................................................... 20
12 Device and Documentation Support ................. 21
12.1
12.2
12.3
12.4
12.5
12.6
Parameter Measurement Information ................ 11
Detailed Description ............................................ 12
8.1 Overview ................................................................. 12
8.2 Functional Block Diagram ....................................... 12
8.3 Feature Description................................................. 13
Documentation Support ........................................
Receiving Notification of Documentation Updates
Support Resources ...............................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
21
21
21
21
21
21
13 Mechanical, Packaging, and Orderable
Information ........................................................... 21
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
2
DATE
REVISION
NOTES
December 2019
*
Initial release.
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5 Pin Configuration and Functions
TLVH431B-EP DBZ Package
3-Pin SOT-23
Top View
REF
1
3
CATHODE
ANODE
2
Not to scale
Pin Functions
PIN
NAME
NO.
TYPE
DESCRIPTION
CATHODE
2
I/O
REF
1
I
Shunt current/voltage input
Threshold relative to common anode
ANODE
3
O
Common pin, normally connected to ground
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6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1)
MIN
VKA
Cathode voltage (2)
IK
Cathode current
Iref
Reference current
TJ
Operating virtual junction temperature
Tstg
Storage temperature
(1)
(2)
MAX
UNIT
20
V
–25
80
mA
–0.05
3
mA
150
°C
150
°C
–65
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
Voltage values are with respect to the anode terminal, unless otherwise noted.
6.2 ESD Ratings
VALUE
V(ESD)
(1)
(2)
Electrostatic discharge
Human body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1)
±2000
Charged device model (CDM), per JEDEC specification JESD22-C101 (2)
±1000
UNIT
V
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
6.3 Recommended Operating Conditions
See (1)
MIN
MAX
UNIT
VKA
Cathode voltage
VREF
18
V
IK
Cathode current (continuous)
0.2
70
mA
TA
Operating free-air temperature
–55
125
°C
(1)
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.
6.4 Thermal Information
TLVH431B-EP
THERMAL METRIC (1)
DBZ (SOT-23)
UNIT
3 PINS
RθJA
Junction-to-ambient thermal resistance
226.5
°C/W
RθJC(top)
Junction-to-case (top) thermal resistance
91.5
°C/W
RθJB
Junction-to-board thermal resistance
45.0
°C/W
ψJT
Junction-to-top characterization parameter
3.0
°C/W
ψJB
Junction-to-board characterization parameter
44.7
°C/W
(1)
4
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report.
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6.5 Electrical Characteristics
at –55°C to 125°C free-air temperature (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
TA = 25°C
1.234
1.24
1.246
TA = full range (1)
1.221
VREF
Reference voltage
VKA = VREF,
IK = 10 mA, see Figure 23
VREF(dev)
VREF deviation (2)
VKA = VREF, IK = 10 mA, see Figure 23
DVREF
DVKA
Ratio of VREF change to
cathode voltage change
IK = 10 mA, VK = VREF to 18 V,
see Figure 24
Iref
Reference terminal current
IK = 10 mA, R1 = 10 kΩ, R2 =
open, see Figure 24
Iref(dev)
Iref deviation (2)
IK = 10 mA, R1 = 10 kΩ, R2 = open,
see Figure 24 (1)
IK(min)
Minimum cathode current for
regulation
VKA = VREF, see Figure 23
IK(off)
Off-state cathode current
VREF = 0, VKA = 18 V,
see Figure 25
|zKA|
Dynamic impedance (3)
VKA = VREF, f ≤ 1 kHz, IK = 0.2
mA to 70 mA, see Figure 23
(1)
(2)
(3)
1.265
UNIT
V
11
31
TA = 25°C
–1.5
–2.7
mV/V
TA = 25°C
0.1
0.5
μA
0.15
0.5
μA
60
100
TA = 25°C
TA = full range (1)
TA = 25°C
TA = full range
TA = 25°C
200
0.02
(1)
0.1
0.7
0.25
0.4
mV
μA
μA
Ω
Full temperature range is –55°C to 125°C.
The deviation parameters VREF(dev) and Iref(dev) are defined as the differences between the maximum and minimum values obtained over
the rated temperature range. The average full-range temperature coefficient of the reference input voltage, αVREF, is defined as:
VREF(dev )
æ
ö
6
ç
÷ ´ 10
=
°
V
T
25
C
(
)
ppm
æ
ö = è REF A
ø
aVREF ç
÷
DTA
è °C ø
where ΔTA is the rated operating free-air temperature range of the device.
αVREF can be positive or negative, depending on whether minimum VREF or maximum VREF, respectively, occurs at the lower
temperature.
The dynamic impedance is defined as:
DVKA
zka =
DIK
When the device is operating with two external resistors (see Figure 24), the total dynamic impedance of the circuit is defined as:
z ka
¢=
DV
DI
»
z ka
æ
è
´ ç1 +
R1 ö
÷
R2 ø
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6.6 Typical Characteristics
Operation of the device at these or any other conditions beyond those indicated in the Recommended Operating Conditions
table are not implied.
250
IREF - Reference Input Current (nA)
VREF - Reference Voltage (V)
1.252
1.25
1.248
1.246
1.244
1.242
1.24
1.238
-55
-30
-5
20
45
70
TJ - Junction Temperature (qC)
95
225
200
175
150
125
100
75
50
-55
120
-30
Figure 1. Reference Voltage
vs Junction Temperature
95
120
D002
Figure 2. Reference Input Current
vs Junction Temperature
250
70
~
~
200
10
150
I K − Cathode Current − µ A
I K − Cathode Current − mA
-5
20
45
70
TJ - Junction Temperature (qC)
D001
~
~
5
0
−5
100
50
0
−50
− 100
− 150
−10
− 200
−15
−1
VKA = VREF
−0.5
0
0.5
1
VKA − Cathode Voltage − V
− 250
−1
1.5
TA = 25°C
VKA = VREF
120
115
110
105
100
95
90
85
80
75
70
65
60
55
50
-55
TA = 25°C
500
-30
-5
20
45
70
TJ - Junction Temperature (qC)
95
120
450
400
350
300
250
200
150
100
50
0
-55
-30
D003
Figure 5. Minimum Cathode Current
vs Junction Temperature
6
1.5
Figure 4. Cathode Current
vs Cathode Voltage
IK(off) - Off-State Cathode Current (PA)
IK(min) - Minimum Cathode Current (PA)
Figure 3. Cathode Current
vs Cathode Voltage
− 0.5
0
0.5
1
VKA − Cathode Voltage − V
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-5
20
45
70
TJ - Junction Temperature (qC)
95
120
D004
Figure 6. Off-State Cathode Current
vs Junction Temperature
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Typical Characteristics (continued)
0.025
0
-0.1
V ref− %
Percentage Change in Vref
'VREF/'VKA - Ratio of Delta Reference Voltage
to Delta Cathode Voltage (mV/V)
Operation of the device at these or any other conditions beyond those indicated in the Recommended Operating Conditions
table are not implied.
-0.2
-0.3
-0.4
-0.5
-0.6
-0.7
-0.8
0
% Change (avg)
− 0.025
% Change (3δ)
− 0.05
− 0.075
− 0.1
-0.9
-1
-55
% Change (−3δ)
-30
-5
20
45
70
TJ - Junction Temperature (qC)
95
120
− 0.125
0
10
20
30
40
50
60
Operating Life at 55°C − kh(1)
D005
(1) Extrapolated from life-test data taken at 125°C; the activation
energy assumed is 0.7 eV.
IK = 1 mA
Figure 7. Ratio of Delta Reference Voltage to Delta Cathode
Voltage vs Junction Temperature
Figure 8. Percentage Change in VREF
vs Operating Life at 55°C
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Typical Characteristics (continued)
Operation of the device at these or any other conditions beyond those indicated in the Recommended Operating Conditions
table are not implied.
3V
Vn − Equivalent Input Noise Voltage − (nV/ Hz)
350
1 kW
300
+
750 W
470 mF
250
200
TLE2027
2200 mF
+
+
_
TP
820 W
TLVH431
TLVH432
160 kW
150
10
100
10 k
1k
f – Frequency – (Hz)
VKA = VREF
160 W
100 k
IK = 1 mA
TA = 25°C
Figure 9. Equivalent Input Noise Voltage
vs Frequency
Figure 10. Test Circuit for Equivalent Noise Voltage
3V
Vn − Equivalent Input Noise Voltage − (mV)
10
8
1 kW
6
+
470 mF
4
750 W
0.47 mF
2200 mF
+
2
820 W
0
TLVH431
TLVH432
TLE2027
10 kW
+
_
160 kW
10 kW
TLE2027
+
_
2.2 mF
+
1 mF
−2
TP
CRO 1 MW
33 kW
16 W
−4
0.1 mF
33 kW
−6
−8
−10
0
2
4
8
6
10
t − Time − (s)
f = 0.1 Hz to 10 Hz
IK = 1 mA
TA = 25°C
Figure 12. Test Circuit for 0.1-Hz to 10-Hz
Equivalent Noise Voltage
80
0°
70
36°
60
72°
50
108°
40
144°
30
180°
Output
Phase Shift
A V − Small-Signal Voltage Gain/Phase Margin − (dB)
Figure 11. Equivalent Input Noise Voltage
Over a 10-s Period
6.8 kW
IK
180 W
10 mF
5V
4.3 kW
20
10
GND
0
−10
−20
100
1k
10 k
100 k
1M
f − Frequency − (Hz)
IK = 1 mA
TA = 25°C
Figure 13. Voltage Gain and Phase Margin
vs Frequency
8
Figure 14. Test Circuit for Voltage Gain and Phase Margin
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Typical Characteristics (continued)
Operation of the device at these or any other conditions beyond those indicated in the Recommended Operating Conditions
table are not implied.
18 kΩ
3.5
3
Input and Output Voltage − V
Output
Input
Ik
2.5
Pulse
Generator
f = 100 kHz
2
1.5
50 Ω
Output
1
GND
0.5
0
− 0.5
0
1
2
3
4
5
6
7
8
t − Time − µs
R = 18 kΩ
TA = 25°C
Figure 16. Test Circuit for Pulse Response 1
Figure 15. Pulse Response 1
3.5
1.8 kΩ
3
Input and Output Voltage − V
Output
Input
IK
2.5
Pulse
Generator
f = 100 kHz
2
1.5
50 Ω
Output
1
GND
0.5
0
− 0.5
0
1
2
3
4
5
6
7
8
t − Time − µs
R = 1.8 kΩ
TA = 25°C
Figure 18. Test Circuit for Pulse Response 2
Figure 17. Pulse Response 2
IK
30 kW
IK
50 W
100 µF
I2
CL
I1
VKA = VREF (1.25 V)
Figure 19. Phase Margin Test Circuit
TA = 25°C
Figure 20. Phase Margin vs Capacitive Load
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Typical Characteristics (continued)
Operation of the device at these or any other conditions beyond those indicated in the Recommended Operating Conditions
table are not implied.
IK
VKA = 2.5 V
TA = 25°C
VKA = 5 V
Figure 21. Phase Margin vs Capacitive Load
10
IK
TA = 25°C
Figure 22. Phase Margin vs Capacitive Load
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7 Parameter Measurement Information
Input
VO
IK
VREF
Figure 23. Test Circuit for VKA = VREF, VO = VKA = VREF
Input
VO
IK
R1
R2
Iref
VREF
Figure 24. Test Circuit for VKA > VREF, VO = VKA = VREF × (1 + R1 / R2) + Iref × R1
Input
VO
IK(off)
Figure 25. Test Circuit for IK(off)
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8 Detailed Description
8.1 Overview
TLVH431B-EP is a low power counterpart to TL431, having lower reference voltage (1.24 V versus 2.5 V) for
lower voltage adjustability and lower minimum cathode current (Ik(min) = 200 µA versus 1 mA). Like TL431,
TLVH431B-EP is used in conjunction with its key components to behave as a single voltage reference, error
amplifier, voltage clamp or comparator with integrated reference.
TLVH431B-EP is also a higher voltage counterpart to TLV431, with cathode voltage adjustability from 1.24 V to
18 V, making this part optimum for a wide range of end equipments in industrial, auto, telecom and computing. In
order for this device to behave as a shunt regulator or error amplifier, > 200 µA (Imin(max)) must be supplied in to
the cathode pin. Under this condition, feedback can be applied from the Cathode and Ref pins to create a replica
of the internal reference voltage.
The reference voltage initial tolerance (at 25°C) is 0.5% and these devices are characterized for operation from
–55°C to 125°C.
8.2 Functional Block Diagram
CATHODE
REF
+
−
VREF = 1.24 V
ANODE
Figure 26. Equivalent Schematic
12
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Functional Block Diagram (continued)
Cathode
REF
Anode
Figure 27. Detailed Schematic
8.3 Feature Description
TLVH431B-EP consists of an internal reference and amplifier that outputs a sink current base on the difference
between the reference pin and the virtual internal pin. The sink current is produced by an internal Darlington pair.
When operated with enough voltage headroom (≥ 1.24 V) and cathode current (Ika), TLVH431B-EP forces the
reference pin to 1.24 V. However, the reference pin can not be left floating, as it needs Iref ≥ 0.5 µA (see the
Specifications section). This is because the reference pin is driven into an NPN, which needs base current in
order operate properly.
When feedback is applied from the Cathode and Reference pins, TLVH431B-EP behaves as a Zener diode,
regulating to a constant voltage dependent on current being supplied into the cathode. This is due to the internal
amplifier and reference entering the proper operating regions. The same amount of current needed in the above
feedback situation must be applied to this device in open loop, servo, or error amplifying implementations in
order for it to be in the proper linear region giving TLVH431B-EP enough gain.
Unlike many linear regulators, TLVH431B-EP is internally compensated to be stable without an output capacitor
between the cathode and anode. If instead it is desired to use an output capacitor, Figure 20, Figure 21, and
Figure 22 can be used as a guide to assist in choosing the correct capacitor to maintain stability.
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8.4 Device Functional Modes
8.4.1 Open Loop (Comparator)
When the cathode/output voltage or current of TLVH431B-EP is not being fed back to the reference/input pin in
any form, this device is operating in open loop. With proper cathode current (Ika) applied to this device,
TLVH431B-EP has the characteristics shown in Figure 4. With such high gain in this configuration, the
TLVH431B-EP device is typically used as a comparator. With the reference integrated makes TLVH431B-EP the
preferred choice when users are trying to monitor a certain level of a single signal.
8.4.2 Closed Loop
When the cathode/output voltage or current of TLVH431B-EP is being fed back to the reference/input pin in any
form, this device is operating in closed loop. The majority of applications involving TLVH431B-EP use it in this
manner to regulate a fixed voltage or current. The feedback enables this device to behave as an error amplifier,
computing a portion of the output voltage and adjusting it to maintain the desired regulation. This is done by
relating the output voltage back to the reference pin in a manner to make it equal to the internal reference
voltage, which can be accomplished through resistive or direct feedback.
14
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9 Applications and Implementation
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
9.1 Application Information
Figure 28 shows the TLVH431B-EP used in a 3.3-V isolated flyback supply. Output voltage VO can be as low as
reference voltage VREF (1.24 V ± 1%). The output of the regulator, plus the forward voltage drop of the
optocoupler LED (1.24 + 1.4 = 2.64 V), determine the minimum voltage that can be regulated in an isolated
supply configuration. Regulated voltage as low as 2.7 Vdc is possible in the topology shown in Figure 28.
The TLVH431B-EP family of devices are prevalent in these applications, being designers go to choice for
secondary side regulation. Due to this prevalence, this section explains operation and design in both states of
TLVH431B-EP that this application will see, open loop (Comparator + VREF) and closed loop (Shunt Regulator).
Further information about system stability and using a TLVH431B-EP device for compensation see
Compensation Design With TL431 for UCC28600, SLUA671.
~
VI
120 V
−
+
P
~
VO
3.3 V
P
P
Gate Drive
VCC
Controller
VFB
TLVH431
Current
Sense
GND
P
P
P
P
Figure 28. Flyback With Isolation Using TLVH431B-EP
as Voltage Reference and Error Amplifier
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9.2 Typical Applications
9.2.1 Comparator With Integrated Reference (Open Loop)
Vsup
Rsup
Vout
CATHODE
R1
RIN
VIN
REF
VL
+
R2
1.24 V
ANODE
Figure 29. Comparator Application Schematic
9.2.1.1 Design Requirements
For this design example, use the parameters listed in Table 1 as the input parameters.
Table 1. Design Parameters
DESIGN PARAMETER
EXAMPLE VALUE
Input Voltage Range
0 V to 5 V
Input Resistance
10 kΩ
Supply Voltage
9V
Cathode Current (Ik)
500 µA
Output Voltage Level
~1 V – Vsup
Logic Input Thresholds VIH/VIL
VL
9.2.1.2 Detailed Design Procedure
When using TLVH431B-EP as a comparator with reference, determine the following:
• Input voltage range
• Reference voltage accuracy
• Output logic input high and low level thresholds
• Current source resistance
9.2.1.2.1 Basic Operation
In the configuration shown in Figure 29, TLVH431B-EP behaves as a comparator, comparing the Vref pin voltage
to the internal virtual reference voltage. When provided a proper cathode current (Ik), TLVH431B-EP will have
enough open loop gain to provide a quick response. With the TLVH431B-EP's max Operating Current (Imin) being
100 uA and up to 150 uA over temperature, operation below that could result in low gain, leading to a slow
response.
16
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9.2.1.2.2 Overdrive
Slow or inaccurate responses can also occur when the reference pin is not provided enough overdrive voltage.
This is the amount of voltage that is higher than the internal virtual reference. The internal virtual reference
voltage will be within the range of 1.24 V ±(0.5%, 1.0% or 1.5%) depending on which version is being used.
The more overdrive voltage provided, the faster the TLVH431B-EP will respond. See Figure 30 and Figure 31 for
the output responses to various input voltages.
For applications where TLVH431B-EP is being used as a comparator, it is best to set the trip point greater than
the positive expected error (that is, +1.0% for the A version). For fast response, setting the trip point to > 10% of
the internal Vref should suffice.
For minimal voltage drop or difference from Vin to the ref pin, it is recommended to use an input resistor < 10 kΩ
to provide Iref.
9.2.1.2.3 Output Voltage and Logic Input Level
In order for TLVH431B-EP to properly be used as a comparator, the logic output must be readable by the
receiving logic device. This is accomplished by knowing the input high and low level threshold voltage levels,
typically denoted by VIH and VIL.
As shown in Figure 30 and Figure 31, TLVH431B-EP's output low level voltage in open-loop/comparator mode is
approximately 1 V, which is sufficient for some 3.3-V supplied logic. However, would not work for 2.5-V and 1.8-V
supplied logic. To accommodate this a resistive divider can be tied to the output to attenuate the output voltage
to a voltage legible to the receiving low-voltage logic device.
TLVH431B-EP's output high voltage is approximately VSUP due to TLVH431B-EP being open-collector. If VSUP is
much higher than the receiving logic's maximum input voltage tolerance, the output must be attenuated to
accommodate the outgoing logic's reliability.
When using a resistive divider on the output, be sure to make the sum of the resistive divider (R1 and R2 in
Figure 29) is much greater than RSUP in order to not interfere with TLVH431B-EP's ability to pull close to VSUP
when turning off.
9.2.1.2.3.1 Input Resistance
TLVH431B-EP requires an input resistance in this application in order to source the reference current (IREF)
needed from this device to be in the proper operating regions while turning on. The actual voltage seen at the ref
pin will be VREF = VIN – IREF × RIN. Because IREF can be as high as 0.5 µA, TI recommends to use a resistance
small enough that will mitigate the error that IREF creates from VIN.
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
-0.4
10
Vin~1.24V (+/-5%)
Vo(Vin=1.18V)
Vo(Vin=1.24V)
Vo(Vin=1.30V)
9
Vo(Vin=5.0V)
Vin=5.0V
8
7
6
Voltage (V)
Voltage (V)
9.2.1.3 Application Curves
5
4
3
2
1
0
-1
-0.2
0
0.2
0.4
Time (ms)
0.6
-2
-0.4
0.8
-0.2
D001
Figure 30. Output Response With Small Overdrive
Voltages
0
0.2
0.4
Time (ms)
0.6
0.8
D001
Figure 31. Output Response With Large Overdrive Voltage
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TLVH431B-EP
SLVSFF4 – DECEMBER 2019
www.ti.com
9.2.2 Shunt Regulator/Reference
RSUP
VSUP
VO
(1
R1
R2
) VREF
R1
CATHODE
0.1%
REF
VREF
TLVH431
CL
R2
0.1%
ANODE
Copyright © 2016, Texas Instruments Incorporated
Figure 32. Shunt Regulator Schematic
9.2.2.1 Design Requirements
For this design example, use the parameters listed in Table 2 as the input parameters.
Table 2. Design Parameters
DESIGN PARAMETER
EXAMPLE VALUE
Reference Initial Accuracy
1.0%
Supply Voltage
6V
Cathode Current (Ik)
500 µA
Output Voltage Level
1.24 V - 18 V
Load Capacitance
100 nF
Feedback Resistor Values and
Accuracy (R1 and R2)
10 kΩ
9.2.2.2 Detailed Design Procedure
When using TLVH431B-EP as a Shunt Regulator, determine the following:
• Input voltage range
• Temperature range
• Total accuracy
• Cathode current
• Reference initial accuracy
• Output capacitance
9.2.2.2.1 Programming Output/Cathode Voltage
To program the cathode voltage to a regulated voltage a resistive bridge must be shunted between the cathode
and anode pins with the mid point tied to the reference pin. This can be seen in Figure 32, with R1 and R2 being
the resistive bridge. The cathode/output voltage in the shunt regulator configuration can be approximated by the
equation shown in Figure 32. The cathode voltage can be more accurately determined by taking in to account
the cathode current:
VO=(1 + R1 / R2) × VREF –I REF × R1
In order for this equation to be valid, TLVH431B-EP must be fully biased so that it has enough open loop gain to
mitigate any gain error. This can be done by meeting the Imin spec denoted in the Specifications section.
18
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9.2.2.2.2 Total Accuracy
When programming the output above unity gain (VKA = VREF), TLVH431B-EP is susceptible to other errors that
may effect the overall accuracy beyond VREF. These errors include:
•
•
•
•
R1 and R2 accuracies
VI(dev) - Change in reference voltage over temperature
ΔVref / ΔVKA - Change in reference voltage to the change in cathode voltage
|zKA| - Dynamic impedance, causing a change in cathode voltage with cathode current
Worst case, cathode voltage can be determined taking all of the variables in to account. The application note
Setting the Shunt Voltage on an Adjustable Shunt Regulator, SLVA445, assists designers in setting the shunt
voltage to achieve optimum accuracy for this device.
9.2.2.2.3 Stability
Though TLVH431B-EP is stable with no capacitive load, the device that receives the shunt regulator's output
voltage could present a capacitive load that is within the TLVH431B-EP region of stability, shown in Figure 20,
Figure 21 and Figure 22. Also, designers may use capacitive loads to improve the transient response or for
power supply decoupling.
TI recommends to choose capacitors that will give a phase margin > 5° to assure stability of the TLVH431B-EP.
Voltage (V)
9.2.2.3 Application Curve
6.5
6
5.5
5
4.5
4
3.5
3
2.5
2
1.5
1
0.5
0
-0.5
-1E-6
Vsup
Vka=Vref
R1=10k: & R2=10k:
1E-6
3E-6
5E-6
Time (s)
7E-6
9E-6
D001
Figure 33. TLVH431B-EP Start-Up Response
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TLVH431B-EP
SLVSFF4 – DECEMBER 2019
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10 Power Supply Recommendations
When using TLVH431B-EP as a Linear Regulator to supply a load, designers will typically use a bypass
capacitor on the output/cathode pin. When doing this, be sure that the capacitance is within the stability criteria
shown in Figure 20, Figure 21, and Figure 22.
To not exceed the maximum cathode current, be sure that the supply voltage is current limited. Also, limit the
current being driven into the Ref pin, as not to exceed its absolute maximum rating.
For applications shunting high currents, pay attention to the cathode and anode trace lengths, adjusting the width
of the traces to have the proper current density.
11 Layout
11.1 Layout Guidelines
Place decoupling capacitors as close to the device as possible. Use appropriate widths for traces when shunting
high currents to avoid excessive voltage drops.
11.2 Layout Example
DBZ
(TOP VIEW)
Rref
Vin
REF
1
Rsup
Vsup
ANODE
3
CATHODE
2
GND
CL
GND
Figure 34. DBZ Layout Example
20
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12 Device and Documentation Support
12.1 Documentation Support
12.1.1 Related Documentation
For related documentation see the following:
• Compensation Design With TL431 for UCC28600, SLUA671
• Setting the Shunt Voltage on an Adjustable Shunt Regulator, SLVA445
12.2 Receiving Notification of Documentation Updates
To receive notification of documentation updates, navigate to the device product folder on ti.com. In the upper
right corner, click on Alert me to register and receive a weekly digest of any product information that has
changed. For change details, review the revision history included in any revised document.
12.3 Support Resources
TI E2E™ support forums are an engineer's go-to source for fast, verified answers and design help — straight
from the experts. Search existing answers or ask your own question to get the quick design help you need.
Linked content is provided "AS IS" by the respective contributors. They do not constitute TI specifications and do
not necessarily reflect TI's views; see TI's Terms of Use.
12.4 Trademarks
E2E is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
12.5 Electrostatic Discharge Caution
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
12.6 Glossary
SLYZ022 — TI Glossary.
This glossary lists and explains terms, acronyms, and definitions.
13 Mechanical, Packaging, and Orderable Information
The following pages include mechanical packaging and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser based versions of this data sheet, refer to the left hand navigation.
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21
PACKAGE OPTION ADDENDUM
www.ti.com
12-Dec-2019
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
Lead/Ball Finish
MSL Peak Temp
(2)
(6)
(3)
Op Temp (°C)
Device Marking
(4/5)
TLVH431BMDBZREP
ACTIVE
SOT-23
DBZ
3
3000
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-55 to 125
V62/19622-01XE
ACTIVE
SOT-23
DBZ
3
3000
Green (RoHS
& no Sb/Br)
CU NIPDAU
Level-2-260C-1 YEAR
-55 to 125
(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)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based
flame retardants must also meet the <=1000ppm threshold requirement.
(3)
MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4)
There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.
(5)
Multiple Device Markings will be inside parentheses. Only one Device 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 Device Marking for that device.
(6)
Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish
value exceeds the maximum column width.
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.
Addendum-Page 1
Samples
PACKAGE OPTION ADDENDUM
www.ti.com
12-Dec-2019
OTHER QUALIFIED VERSIONS OF TLVH431B-EP :
• Catalog: TLVH431B
• Automotive: TLVH431B-Q1
NOTE: Qualified Version Definitions:
• Catalog - TI's standard catalog product
• Automotive - Q100 devices qualified for high-reliability automotive applications targeting zero defects
Addendum-Page 2
PACKAGE MATERIALS INFORMATION
www.ti.com
11-Dec-2019
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device
TLVH431BMDBZREP
Package Package Pins
Type Drawing
SPQ
SOT-23
3000
DBZ
3
Reel
Reel
A0
Diameter Width (mm)
(mm) W1 (mm)
180.0
8.4
Pack Materials-Page 1
3.15
B0
(mm)
K0
(mm)
P1
(mm)
2.77
1.22
4.0
W
Pin1
(mm) Quadrant
8.0
Q3
PACKAGE MATERIALS INFORMATION
www.ti.com
11-Dec-2019
*All dimensions are nominal
Device
Package Type
Package Drawing
Pins
SPQ
Length (mm)
Width (mm)
Height (mm)
TLVH431BMDBZREP
SOT-23
DBZ
3
3000
213.0
191.0
35.0
Pack Materials-Page 2
4203227/C
PACKAGE OUTLINE
DBZ0003A
SOT-23 - 1.12 mm max height
SCALE 4.000
SMALL OUTLINE TRANSISTOR
C
2.64
2.10
1.4
1.2
PIN 1
INDEX AREA
1.12 MAX
B
A
0.1 C
1
0.95
3.04
2.80
1.9
3X
3
0.5
0.3
0.2
2
(0.95)
C A B
0.25
GAGE PLANE
0 -8 TYP
0.10
TYP
0.01
0.20
TYP
0.08
0.6
TYP
0.2
SEATING PLANE
4214838/C 04/2017
NOTES:
1. All linear dimensions are in millimeters. Any dimensions in parenthesis are for reference only. Dimensioning and tolerancing
per ASME Y14.5M.
2. This drawing is subject to change without notice.
3. Reference JEDEC registration TO-236, except minimum foot length.
www.ti.com
EXAMPLE BOARD LAYOUT
DBZ0003A
SOT-23 - 1.12 mm max height
SMALL OUTLINE TRANSISTOR
PKG
3X (1.3)
1
3X (0.6)
SYMM
3
2X (0.95)
2
(R0.05) TYP
(2.1)
LAND PATTERN EXAMPLE
SCALE:15X
SOLDER MASK
OPENING
METAL
SOLDER MASK
OPENING
METAL UNDER
SOLDER MASK
0.07 MIN
ALL AROUND
0.07 MAX
ALL AROUND
NON SOLDER MASK
DEFINED
(PREFERRED)
SOLDER MASK
DEFINED
SOLDER MASK DETAILS
4214838/C 04/2017
NOTES: (continued)
4. Publication IPC-7351 may have alternate designs.
5. Solder mask tolerances between and around signal pads can vary based on board fabrication site.
www.ti.com
EXAMPLE STENCIL DESIGN
DBZ0003A
SOT-23 - 1.12 mm max height
SMALL OUTLINE TRANSISTOR
PKG
3X (1.3)
1
3X (0.6)
SYMM
3
2X(0.95)
2
(R0.05) TYP
(2.1)
SOLDER PASTE EXAMPLE
BASED ON 0.125 THICK STENCIL
SCALE:15X
4214838/C 04/2017
NOTES: (continued)
6. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate
design recommendations.
7. Board assembly site may have different recommendations for stencil design.
www.ti.com
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