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ATL431LI-Q1
ATL432LI-Q1
SNVSBB0A – MAY 2019 – REVISED NOVEMBER 2019
ATL431LI-Q1 / ATL432LI-Q1 High Bandwidth Low-IQ Programmable Shunt Regulator
1 Features
3 Description
•
•
The ATL43xLI-Q1 is a three-terminal adjustable shunt
regulator, with specified thermal stability over
applicable automotive, commercial, and military
temperature ranges. Its output voltage can be set to
any value between Vref (approximately 2.5 V) and 36
V with two external resistors. The device has a typical
output impedance of 0.3 Ω. Its active output circuitry
provides a very sharp turn-on characteristic, making it
an excellent replacement for Zener diodes in many
applications, such as onboard regulation, adjustable
power supplies, and switching power supplies. This
device is a pin-to-pin alternative to the TL431LI-Q1
and TL432LI-Q1, with lower minimum operating
current to help reduce system power consumption.
The ATL432LI-Q1 has exactly the same functionality
and electrical specifications as the ATL431LI-Q1, but
has a different pinout for the DBZ package.
1
•
•
•
•
•
•
•
•
•
Qualified for automotive applications
AEC-Q100 qualified with the following results:
– Device temperature grade 1: –40°C to +125°C
ambient operating temperature
Reference voltage tolerance at 25°C
– 0.5% (B grade)
– 1% (A grade)
Minimum typical output voltage: 2.5 V
Adjustable output voltage: Vref to 36 V
Operation from −40°C to +125°C
27 mV maximum temperature drift
0.3-Ω typical output impedance
Sink-current capability
– Imin = 0.08 mA (max)
– IKA = 15 mA (max)
Reference input current IREF: 0.4 μA (max)
Deviation of reference input current over
temperature, II(dev): 0.3 μA (max)
The ATL431LI-Q1 is offered in two grades, with initial
tolerances (at 25°C) of 0.5%, and 1%, for the B and A
grade,
respectively.
The
ATL43xLI-Q1
is
characterized for operation from –40°C to +125°C,
and its low output drift versus temperature ensures
good stability over the entire temperature range.
2 Applications
•
•
•
•
•
Device Information(1)
Inverter and motor control
DC/DC converter
LED lighting
On-board charger (OBC)
Infotainment and cluster
PART NUMBER
ATL43xLI
PACKAGE (PIN)
SOT-23 (3)
BODY SIZE (NOM)
2.90 mm x 1.30 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Simplified Schematic
VKA
Input
IKA
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.
ATL431LI-Q1
ATL432LI-Q1
SNVSBB0A – MAY 2019 – REVISED NOVEMBER 2019
www.ti.com
Table of Contents
1
2
3
4
5
6
7
8
Features ..................................................................
Applications ...........................................................
Description .............................................................
Revision History.....................................................
Device Comparison Table.....................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
2
3
3
4
7.1
7.2
7.3
7.4
7.5
7.6
4
4
4
4
5
6
Absolute Maximum Ratings ......................................
ESD Ratings..............................................................
Recommended Operating Conditions.......................
Thermal Information ..................................................
Electrical Characteristics...........................................
Typical Characteristics ..............................................
Parameter Measurement Information .................. 9
8.1 Temperature Coefficient............................................ 9
8.2 Dynamic Impedance ............................................... 10
9
Detailed Description ............................................ 11
9.1 Overview ................................................................. 11
9.2 Functional Block Diagram ....................................... 11
9.3 Feature Description................................................. 13
9.4 Device Functional Modes........................................ 13
10 Applications and Implementation...................... 14
10.1 Application Information.......................................... 14
10.2 Typical Applications .............................................. 14
10.3 System Examples ................................................. 24
11 Power Supply Recommendations ..................... 27
12 Layout................................................................... 27
12.1 Layout Guidelines ................................................. 27
12.2 Layout Example .................................................... 27
13 Device and Documentation Support ................. 28
13.1
13.2
13.3
13.4
13.5
13.6
13.7
13.8
Device Support......................................................
Documentation Support ........................................
Related Links ........................................................
Receiving Notification of Documentation Updates
Support Resources ...............................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
28
28
28
28
28
28
29
29
14 Mechanical, Packaging, and Orderable
Information ........................................................... 29
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Original (May 2019) to Revision A
•
2
Page
Changed device status from Advance Information to Production Data ................................................................................. 1
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SNVSBB0A – MAY 2019 – REVISED NOVEMBER 2019
5 Device Comparison Table
DEVICE PINOUT
INITIAL ACCURACY
OPERATING FREE-AIR TEMPERATURE (TA)
ATL431LI-Q1
ATL432LI-Q1
A: 1%
B: 0.5%
Q: -40°C to 125°C
6 Pin Configuration and Functions
ATL431LI-Q1 DBZ Package
3-Pin SOT-23
Top View
CATHODE
ATL432LI-Q1 DBZ Package
3-Pin SOT-23
Top View
1
3
REF
ANODE
1
3
REF
ANODE
2
CATHODE
2
Pin Functions
PIN
NAME
ATL431LI-Q1
ATL432LI-Q1
DBZ
DBZ
TYPE
DESCRIPTION
ANODE
3
3
O
Common pin, normally connected to ground
CATHODE
1
2
I/O
Shunt Current/Voltage input
REF
2
1
I
Threshold relative to common anode
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7 Specifications
7.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1)
MIN
VKA
Cathode Voltage (2)
IKA
Continuos Cathode Current Range
II(ref)
Reference Input Current
TJ
Tstg
(1)
(2)
MAX
UNIT
37
V
–10
18
mA
–5
10
mA
Operating Junction Temperature Range
–40
150
C
Storage Temperature Range
–65
150
C
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.
All voltage values are with respect to ANODE, unless otherwise noted.
7.2 ESD Ratings
VALUE
Electrostatic
discharge
V(ESD)
(1)
Human body model (HBM), per AEC Q100-002 (1)
±4000
Charged-device model (CDM), per AEC Q100-011
±1000
UNIT
V
AEC Q100-002 indicates that HBM stressing shall be in accordance with the ANSI/ESDA/JEDEC JS-001 specification
7.3 Recommended Operating Conditions
MIN
MAX
UNIT
VKA
Cathode Voltage
VREF
36
V
IKA
Continuous Cathode Current Range
0.08
15
mA
TA
Operating Free-Air Temperature (1)
–40
125
C
(1)
ATL43xLIxQ
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 can affect reliability. See the Semiconductor and IC
Package Thermal Metrics Application Report for more information.
7.4 Thermal Information
ATL43xLI
THERMAL METRIC (1)
DBZ
UNIT
3 PINS
RθJA
Junction-to-ambient thermal resistance
371.7
C/W
RθJC(top)
Junction-to-case (top) thermal resistance
145.9
C/W
RθJB
Junction-to-board thermal resistance
104.7
C/W
ψJT
Junction-to-top characterization parameter
23.9
C/W
ψJB
Juction-to-board characterization parameter
102.9
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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7.5 Electrical Characteristics
over recommended operating conditions, TA = 25°C (unless otherwise noted)
PARAMETER
TEST CIRCUIT
TEST CONDITIONS
VREF
Reference Voltage
See Figure 17
VKA = Vref, IKA = 1 mA
VI(dev)
Deviation of reference
input voltage over full
temperature range (1)
See Figure 17
VKA = Vref, IKA = 1 mA
ΔVref /
ΔVKA
Ratio of change in
reference voltage to the
change in cathode
voltage
See Figure 18
IKA = 1 mA
Iref
Reference Input Current See Figure 18
II(dev)
Deviation of reference
input current over full
temperature range (1)
Imin
Minimum cathode
current for regulation
Ioff
Off-state cathode
current
|ZKA|
(1)
(2)
Dynamic Impedance
(2)
MIN
TYP MAX
UNIT
ATL43xLIAx devices
2475 2500 2525
mV
ATL43xLIBx devices
2487 2500 2512
mV
ATL43xLIxQ devices
10
27
–1.4
–2.7
mV/V
–1
–2
mV/V
IKA = 1 mA, R1 = 10kΩ, R2 = ∞
0.2
0.4
µA
See Figure 18
IKA = 1 mA, R1 = 10kΩ, R2 = ∞
0.1
0.3
µA
See Figure 17
VKA = Vref
65
80
µA
See Figure 19
VKA = 36 V, Vref = 0
0.1
1
µA
See Figure 17
VKA = Vref, IKA = 1 mA to 15 mA
0.65
0.75
Ω
ΔVKA = 10 V - Vref
ΔVKA = 36 V - 10 V
mV
The deviation parameters VI(dev) and II(dev) are defined as the differences between the maximum and minimum values obtained over the
rated temperature range. For more details on VI(dev) and how it relates to the average temperature coefficient, see the Temperature
Coefficient section.
The dynamic impedance is defined by |ZKA| = ΔVKA/ΔIKA. For more details on |ZKA| and how it relates to Vout, see the Temperature
Coefficient section.
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7.6 Typical Characteristics
Data at high and low temperatures are applicable only within the recommended operating free-air temperature
ranges of the various devices.
0.5
2520
IKA = 1 mA
Iref - Reference Current - µA
Vref - Reference Voltage - mV
2515
2510
2505
2500
2495
2490
2485
0.4
0.3
0.2
0.1
2480
2475
-40
-20
0
20
40
60
TA (qC)
80
100
120
0
-50
140
Figure 1. Reference Voltage versus Free-Air Temperature
125
Figure 2. Reference Current versus Free-Air Temperature
200
15
VKA = Vref
175 T = 25°C
A
VKA = Vref
TA = 25°C
12
IKA - Cathode Current - µA
IKA - Cathode Current - mA
-25
0
25
50
75 100
TA - Free-Air Temperature - °C
9
6
3
0
150
125
Imin
100
75
50
25
0
-25
-50
-3
0
0.5
1
1.5
2
2.5
VKA - Cathode Voltage -V
0
3
D003
Figure 3. Cathode Current versus Cathode Voltage
D004
-0.35
VKA = 3 V to 36 V
-0.4
0.016
-0.45
'Vref / 'VKA = mV/V
Ioff - Off-State Cathode Current - PA
2.5
Figure 4. Cathode Current versus Cathode Voltage
0.02
0.012
0.008
-0.5
-0.55
-0.6
-0.65
-0.7
0.004
-0.75
0
-40 -20
0 20 40 60 80 100 120 140
TA - Free-Air Temperature - °C
Figure 5. Off-State Cathode Current
versus Free-Air Temperature
6
0.5
1
1.5
2
VKA - Cathode Voltage - V
-0.8
-50
-25
0
25
50
75
Temperature (°C)
100
125
D006
Figure 6. Ratio of Delta Reference Voltage to Delta Cathode
Voltage versus Free-Air Temperature
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75
200
60
160
45
120
30
80
15
40
IKA = 10 mA
TA = 25°C
Output
Phase - q
AV - Small-Signal Voltage Amplification - dB
Typical Characteristics (continued)
IKA
15 kΩ
9 µF
+
AV
Phase
0
100
1k
10k
100k
f - Frequency - Hz
0
10M
1M
232 Ω
−
8.25 kΩ
D000
GND
Figure 7. Small-Signal Voltage Amplification
versus Frequency
Figure 8. Test Circuit for Voltage Amplification
|ZKA| - Reference Impedance - Ohms
100
1 kΩ
IKA = 1 mA
50 T = 25°C
A
30
20
IKA
10
50 Ω
5
3
2
−
+
1
GND
0.5
0.3
0.2
0.1
1k
10k
100k
f - Frequency - Hz
1M
Figure 9. Reference Impedance versus Frequency
Figure 10. Test Circuit for Reference Impedance
6
Input
Input and Output Voltage - V
Output
220 Ω
TA = 25qC
Output
5
Pulse
Generator
f = 100 kHz
4
3
Output
50 Ω
2
GND
1
0
-1
0
1
2
3
4
t - Time - Ps
5
6
7
puls
Figure 11. Pulse Response
Figure 12. Test Circuit for Pulse Response
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Typical Characteristics (continued)
150 Ω
15
IKA - Cathode Current - mA
13
A VKA = Vref
B VKA = 5 V
C VKA = 10 V
IKA
Stable Region
+
11
VBATT
CL
−
9
7
TEST CIRCUIT FOR CURVE A
5
3
1
0.001
IKA
R1 = 10 kΩ
0.01
0.1
1
CL - Load Capacitance - µF
150 Ω
10
ATL4
The areas under the curves represent conditions that may cause the
device to oscillate. For curves B and C, R2 and V+ are adjusted to
establish the initial VKA and IKA conditions, with CL = 0. VBATT and CL
then are adjusted to determine the ranges of stability.
Figure 13. Stability Boundary Conditions for All ATL431LIQ1, ATL432LI-Q1 Devices Above 1 mA
CL
+
R2
VBATT
−
TEST CIRCUIT FOR CURVES B, C, AND D
Figure 14. Test Circuit for Stability Boundary Conditions
IKA - Cathode Current - mA
1
0.8
150 Ω
A VKA = Vref
B VKA = 5 V
C VKA = 10 V
IKA
+
VBATT
CL
−
0.6
0.4
TEST CIRCUIT FOR CURVE A
Stable Region
0.2
IKA
R1 = 10 kΩ
0
0.001
CL
0.01
0.1
1
CL - Load Capacitance - µF
10
+
R2
ATL4
The areas in-between the curves represent conditions that may cause
the device to oscillate. For curves B and C, R2 and V+ are adjusted
to establish the initial VKA and IKA conditions, with CL = 0. VBATT and
CL then are adjusted to determine the ranges of stability.
Figure 15. Stability Boundary Conditions for All ATL431LIQ1, ATL432LI-Q1 Devices Below 1 mA
8
150 Ω
VBATT
−
TEST CIRCUIT FOR CURVES B, C, AND D
Figure 16. Test Circuit for Stability Boundary Conditions
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8 Parameter Measurement Information
VKA
Input
IKA
Vref
Figure 17. Test Circuit for VKA = Vref
Input
VKA
IKA
R1
Iref
R2
Vref
R1 ö
æ
VKA = Vref ç 1 +
÷ + Iref × R1
R2 ø
è
Figure 18. Test Circuit for VKA > Vref
Input
VKA
Ioff
Figure 19. Test Circuit for Ioff
8.1 Temperature Coefficient
The deviation of the reference voltage, Vref, over the full temperature range is known as VI(dev). The parameter of
VI(dev) can be used to find the temperature coefficient of the device. The average full-range temperature
coefficient of the reference input voltage, αVref, is defined as:
αVref is positive or negative, depending on whether minimum Vref or maximum Vref, respectively, occurs at the
lower temperature. The full-range temperature coefficient is an average and, therefore, any subsection of the
rated operating temperature range can yield a value that is greater or less than the average. For more details on
temperature coefficient, refer to the Voltage Reference Selection Basics White Paper.
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8.2 Dynamic Impedance
'VKA
'IKA . When the device is operating with two external resistors
The dynamic impedance is defined as:
'V
z'
'I , which is approximately equal to
(see Figure 18), the total dynamic impedance of the circuit is given by:
R1 ·
§
ZKA ¨ 1
¸
© R2 ¹ .
ZKA
Itest
P/
IKA (mA)
The VKA of the ATL431LI-Q1 can be affected by the dynamic impedance. The ATL431LI-Q1 test current Itest for
VKA is specified in the Electrical Characteristics. Any deviation from Itest can cause deviation on the output VKA.
Figure 20 shows the effect of the dynamic impedance on the VKA.
IKA
IKA(min)
0
VKA (V)
Ps
Figure 20. Dynamic Impedance
10
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9 Detailed Description
9.1 Overview
This standard device has proven ubiquity and versatility across a wide range of applications, ranging from power
to signal path. This is due to its key components containing an accurate voltage reference and op amp, which
are very fundamental analog building blocks. The ATL431LI-Q1 is used in conjunction with the key components
to behave as the following:
• Single voltage reference
• Error amplifier
• Voltage clamp
• Comparator with integrated reference
ATL431LI-Q1 can be operated and adjusted to cathode voltages from 2.5 V to 36 V, making this part optimal for
a wide range of end equipments in industrial, auto, telecom, and computing. For this device to behave as a shunt
regulator or error amplifier, >80 µA (Imin(maximum)) 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.
Various reference voltage options can be purchased with initial tolerances (at 25°C) of 0.5% and 1%. These
reference options are denoted by B (0.5%) and A (1.0%) after the ATL431LI-Q1 or ATL432LI-Q1. ATL431LI-Q1
and ATL432LI-Q1 are both functionally the same, but have different pinout options. The ATL43xLI-Q1 devices
are characterized for operation from –40°C to +125°C.
9.2 Functional Block Diagram
CATHODE
+
REF
_
Vref
ANODE
Figure 21. Equivalent Schematic
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Functional Block Diagram (continued)
CATHODE
REF
ANODE
Figure 22. Detailed Schematic
12
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9.3 Feature Description
The ATL431LI-Q1 consists of an internal reference and amplifier that outputs a sink current based on the
difference between the reference pin and the virtual internal pin. The sink current is produced by the internal
Darlington pair, shown in Figure 21. A Darlington pair is used for this device to be able to sink a maximum
current of 15 mA.
When operated with enough voltage headroom (≥ 2.5 V) and cathode current (IKA), the ATL431LI-Q1 forces the
reference pin to 2.5 V. However, the reference pin cannot be left floating, as it needs IREF ≥ 0.4 µA (see the
Specifications). This is because the reference pin is driven into an NPN, which needs base current to operate
properly.
When feedback is applied from the Cathode and Reference pins, the ATL431LI-Q1 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 for it to
be in the proper linear region giving ATL431LI-Q1 enough gain.
Unlike many linear regulators, ATL431LI-Q1 is internally compensated to be stable without an output capacitor
between the cathode and anode. However, if it is desired to use an output capacitor Figure 13 can be used as a
guide to assist in choosing the correct capacitor to maintain stability.
9.4 Device Functional Modes
9.4.1 Open Loop (Comparator)
When the cathode/output voltage or current of ATL431LI-Q1 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, the
ATL431LI-Q1 has the characteristics shown in Figure 21. With such high gain in this configuration, the ATL431LIQ1 is typically used as a comparator. With the reference integrated makes ATL431LI-Q1 the preferred choice
when users are trying to monitor a certain level of a single signal.
9.4.2 Closed Loop
When the cathode/output voltage or current of the ATL431LI-Q1 is being fed back to the reference/input pin in
any form, this device is operating in closed loop. The majority of applications involving ATL431LI-Q1 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 via resistive or direct feedback.
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10 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.
10.1 Application Information
As this device has many applications and setups, there are many situations that this data sheet cannot
characterize in detail. The linked application note will help the designer make the best choices when using this
part.
Setting the Shunt Voltage on an Adjustable Shunt Regulator Application Note assists with setting the shunt
voltage to achieve optimum accuracy for this device.
10.2 Typical Applications
10.2.1 Comparator With Integrated Reference
Vsup
Rsup
Vout
CATHODE
R1
VIN
RIN
REF
VL
+
R2
2.5V
ANODE
Figure 23. Comparator Application Schematic
14
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Typical Applications (continued)
10.2.2 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
24 V
Cathode Current (Ik)
5 mA
Output Voltage Level
~2 V – VSUP
Logic Input Thresholds VIH/VIL
VL
10.2.3 Detailed Design Procedure
When using the ATL431LI-Q1 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
10.2.3.1 Basic Operation
In the configuration shown in Figure 23, the ATL431LI-Q1 behaves as a comparator, comparing the VREF pin
voltage to the internal virtual reference voltage. When provided a proper cathode current (IK), ATL431LI-Q1 has
enough open-loop gain to provide a quick response. This can be seen in Figure 24 where the RSUP = 10 kΩ (IKA
= 500 µA) situation responds much slower than RSUP = 1 kΩ (IKA = 5 mA). With the ATL431LI-Q1 max operating
current (IMIN) being 1 mA, operation below that can result in low gain, leading to a slow response.
10.2.3.1.1 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 is within the range of 2.5 V ±(0.5% or 1.0%) depending on which version is being used. The more
overdrive voltage provided, the faster the ATL431LI-Q1 will respond.
For applications where ATL431LI-Q1 is being used as a comparator, it is best to set the trip point to 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 suffices.
For minimal voltage drop or difference from Vin to the ref pin, TI recommends to use an input resistor
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