LM431BQ [SGMICRO]
Automotive Precision Programmable Reference;
| 型号： | LM431BQ |
| 厂家： | 
Shengbang Microelectronics Co, Ltd |
| 描述： | Automotive Precision Programmable Reference |
| 文件： | 总12页 (文件大小：1028K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
LM431BQ
Precision Programmable Reference
GENERAL DESCRIPTION
FEATURES
The LM431BQ is a precision programmable shunt
voltage reference that can be used in automotive
applications. It is a three-terminal adjustable-output
device that can keep stable under all capacitive loads.
It requires two external resistors to set the output
voltage from VREF to 36V.
● AEC-Q100 Qualified for Automotive Applications
Device Temperature Grade 1
TA = -40℃ to +125℃
● Adjustable Output Voltage: VREF to 36V
● Sink-Current Capability: 1mA to 100mA
● ▲Reference Voltage Tolerance at +25℃: 0.5%
● Temperature Drift: 5mV (TYP)
● Output Impedance: 0.1Ω (TYP)
● ▲High Stability under Capacitive Load
● Low Output Noise
The LM431BQ features low dynamic impedance, low
noise, and low temperature coefficient to ensure a
stable output voltage over a wide range of operating
temperatures and currents. These high performances
make it very suitable for multiple applications, such as
precision audio components and flyback switching
power supplies.
● Operating Junction Temperature Range:
-40℃ to +125℃
● Available in a Green SOT-23 Package
This device is AEC-Q100 qualified (Automotive
Electronics Council (AEC) standard Q100 Grade 1) and
it is suitable for automotive applications.
APPLICATIONS
AEC-Q100 Grade 1 Applications
Portable, Battery-Powered Equipment
Voltage Monitoring
The LM431BQ is available in a Green SOT-23 package.
Flyback Switching Power Supplies
Instrumentation
Product Testing
Precision Audio Components
TYPICAL APPLICATION
Input
VKA
IKA
VREF
Figure 1. Typical Application Circuit
SG Micro Corp
JUNE 2022 – REV. A. 1
www.sg-micro.com
LM431BQ
Precision Programmable Reference
PACKAGE/ORDERING INFORMATION
SPECIFIED
TEMPERATURE
RANGE
PACKAGE
DESCRIPTION
ORDERING
NUMBER
PACKAGE
MARKING
PACKING
OPTION
MODEL
LM431BQ
SOT-23
-40℃ to +125℃
LM431BQN3LG/TR
SYLXX
Tape and Reel, 3000
MARKING INFORMATION
NOTE: XX = Date Code.
YYY X X
Date Code - Week
Date Code - Year
Serial Number
Green (RoHS & HSF): SG Micro Corp defines "Green" to mean Pb-Free (RoHS compatible) and free of halogen substances. If
you have additional comments or questions, please contact your SGMICRO representative directly.
OVERSTRESS CAUTION
ABSOLUTE MAXIMUM RATINGS
Cathode Voltage (1), VKA...................................................40V
Continuous Cathode Current Range, IKA .. -100mA to 150mA
Reference Input Current Range, II(REF)....... -0.05mA to 10mA
Package Thermal Resistance
Stresses beyond those listed in Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to
absolute maximum rating conditions for extended periods
may affect reliability. Functional operation of the device at any
conditions beyond those indicated in the Recommended
Operating Conditions section is not implied.
SOT-23, θJA.............................................................. 245℃/W
Junction Temperature .................................................+150℃
Storage Temperature Range........................-65℃ to +150℃
Lead Temperature (Soldering, 10s) ............................+260℃
ESD Susceptibility
ESD SENSITIVITY CAUTION
This integrated circuit can be damaged if ESD protections are
not considered carefully. SGMICRO recommends that all
integrated circuits be handled with appropriate precautions.
Failureto observe proper handlingand installation procedures
can cause damage. ESD damage can range from subtle
performance degradation tocomplete device failure. Precision
integrated circuits may be more susceptible to damage
because even small parametric changes could cause the
device not to meet the published specifications.
HBM.............................................................................4000V
CDM ............................................................................1000V
RECOMMENDED OPERATING CONDITIONS
Cathode Voltage, VKA ..........................................VREF to 36V
Cathode Current, IKA .......................................1mA to 100mA
Operating Junction Temperature Range......-40℃ to +125℃
NOTE:
DISCLAIMER
SG Micro Corp reserves the right to make any change in
1. All voltage values are with respect to ANODE, unless
otherwise noted.
circuit design, or specifications without prior notice.
SG Micro Corp
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JUNE 2022
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LM431BQ
Precision Programmable Reference
PIN CONFIGURATION
(TOP VIEW)
CATHODE
1
2
3
ANODE
REF
SOT-23
PIN DESCRIPTION
PIN
1
NAME
CATHODE
REF
TYPE
FUNCTION
I/O
I
Cathode Pin. Voltage input and shunts current.
REF Input Pin. Threshold Related to the voltage of ANODE Pin.
Anode Pin. Connect to GND directly.
2
3
ANODE
O
NOTE: I: input, O: output, I/O: input or output.
FUNCTIONAL BLOCK DIAGRAM
CATHODE
REF
VREF
ANODE
Figure 2. Equivalent Diagram
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LM431BQ
Precision Programmable Reference
ELECTRICAL CHARACTERISTICS
(Over recommended operating conditions, TJ = +25℃, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
VKA = VREF, IKA = 10mA
VKA = VREF, IKA = 10mA
MIN
TYP
MAX UNITS
(1)
Reference Voltage
▲VREF
2.488
2.500
2.512
25
V
Deviation of Reference Input Voltage over Full
Temperature Range (2)
VI(DEV)
5
mV
ΔVKA = 10V - VREF
ΔVKA = 36V - 10V
-0.5
0.1
1
-1.0
0.5
2
Ratio of Change in Reference Voltage to the
Change in Cathode Voltage
ΔVREF/ΔVKA IKA = 10mA
mV/V
Reference Input Current
IREF
IKA = 10mA, R1 = 10kΩ, R2 = ∞
IKA = 10mA, R1 = 10kΩ, R2 = ∞
µA
µA
Deviation of Reference Input Current over Full
II(DEV)
0.4
0.4
0.8
0.7
Temperature Range (2)
Minimum Cathode Current for Regulation over
Full Temperature Range
IMIN
IOFF
|ZKA
VKA = VREF
mA
Off-State Cathode Current
Dynamic Impedance (3)
VKA = 36V, VREF = 0V
0.1
0.1
1
µA
|
VKA = VREF, f ≤ 1kHz, IKA = 1mA to 100mA
0.5
Ω
NOTES:
1. “▲” refers to special characteristics for automotive applications.
2. VI(DEV) and II(DEV) refer to the difference between the maximum value and the minimum value obtained within the rated
temperature range. αVREF is defined as:
V
I DEV
(
)
× 106
VREF at 25℃
ppm
αVREF
= |
|
℃
∆T
J
where,
ΔTJ is the rated operating junction temperature range of the device.
VREF is the average full-range temperature coefficient of the reference input voltage.
α
3. |ZKA| = ΔVKA / ΔIKA, when the device is operating with two external resistors, the total dynamic impedance of the circuit is equal to
∆V
∆I
, which is approximately equal to
R
1
Z' =
ZKA 1 +
R2
.
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LM431BQ
Precision Programmable Reference
TYPICAL PERFORMANCE CHARACTERISTICS
TJ = +25℃, unless otherwise noted.
Reference Voltage vs. Temperature
Reference Current vs. Temperature
2.51
2.505
2.5
2
1.5
1
2.495
2.49
0.5
0
R1 = 10kΩ, R2 = ∞, IKA = 10mA
VKA = VREF, IKA = 10mA
-40 -25 -10
5
20 35 50 65 80 95 110 125
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (℃)
Temperature (℃)
Cathode Current vs. Cathode Voltage
Cathode Current vs. Cathode Voltage
100
50
600
400
200
0
0
-40℃
-50
-100
+25℃
+125℃
VKA = VREF
VKA = VREF
2.5
-200
-1 -0.5
0
0.5
1
1.5
2
3
-1 -0.5
0
0.5
1
1.5
2
2.5 3
Cathode Voltage (V)
Cathode Voltage (V)
Ratio of Delta Reference Voltage to Delta Cathode Voltage vs.
Off-State Cathode Current vs. Temperature
VKA = 36V, VREF = 0V
Temperature
0
2.5
2
VKA = 2.5V to 36V
-0.03
-0.06
-0.09
-0.12
-0.15
-0.18
1.5
1
0.5
0
-40 -25 -10
5
20 35 50 65 80 95 110 125
-40 -25 -10
5
20 35 50 65 80 95 110 125
Temperature (℃)
Temperature (℃)
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LM431BQ
Precision Programmable Reference
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
TJ = +25℃, unless otherwise noted.
Small-Signal Voltage Amplification vs. Frequency
IKA = 10mA
Reference Impedance vs. Frequency
IKA = 10mA
60
50
40
30
20
10
0
100
10
1
0.1
0.01
1
10
100
1000
10000
1
10
100
1000
10000
Frequency (kHz)
Frequency (kHz)
Equivalent Input Noise Voltage vs. Frequency
Equivalent Input Noise Voltage over a 10s Period
400
350
300
250
200
150
100
50
6
4
2
0
-2
-4
-6
IKA = 10mA
10 100
f = 0.1Hz to 10Hz, IKA = 10mA
0
0.01
0.1
1
0
2
4
6
8
10
Frequency (kHz)
Time (s)
Pulse Response
Input
6
5
4
Output
3
2
1
0
-1
-2.5
-0.5
1.5
3.5
5.5
7.5
Time (μs)
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LM431BQ
Precision Programmable Reference
APPLICATION INFORMATION
inaccurate and slow. On the contrary, the larger
overdrive voltage provided at the REF pin, the faster
the output response will be. Moreover, if the users
desire fast response, the overdrive voltage should be
larger than 10% of the internal voltage reference.
LM431BQ Used as Comparator with
Integrated Reference
VL
R1
R2
The input resistance should be less than 10kΩ in order to
minimize the voltage drop between VIN and VREF. The
readability of the logic output of the comparator should
be guaranteed so that it can be received by the next
stage. In Figure 4, the VIL of the comparator logic is 2V,
which is sufficient for a 5V supply voltage. However, for
the logic stage which is powered by 1.8V or 3.3V, the
VIL is hard to be figured out. To accommodate this, a
voltage divider should be taken into account. Due to the
Open-Collector (OC) output stage, the VIH is equal to
the voltage of its power supply. When the voltage
divider is used to attenuate VIH, please make sure that
the sum of R1 and R2 is greater than the resistance
RSUP
CATHODE
REF
VSUP
RIN
VIN
2.5V
ANODE
Figure 3. Comparator Application Schematic
Table 1. Design Parameters
R
SUP to the power supply.
Design Parameter
Input Voltage Range
Example Value
0V to 5V
10kΩ
However, for this application, an external resistor RIN is
required to provide the IREF and guarantee the normal
operation of the LM431BQ. Also, because of the
voltage drop across RIN, so that the gap between VIN
and VREF is the voltage drop of RIN. To decrease the
error, the selected RIN should be small enough as the
maximum IREF is 2μA.
Input Resistance (RIN)
Supply Voltage Range (VSUP
)
5V to 24V
1kΩ
Supply Resistance (RSUP
Output Voltage Level
)
~ 2V (Logical “Low”)
~ VSUP (Logical “High”)
As shown in Figure 3, the LM431BQ is always used as
a comparator with 2.5V integrated reference in
application, for this design, the parameters are listed in
Table 1. The REF pin voltage is compared with
reference inside and is amplified. Also, the LM431BQ
responds fast if the operation current IKA is large
enough. In Figure 4, it is clear to see that the output
5.5
RSUP = 1kΩ
RSUP = 10kΩ
4.5
3.5
2.5
1.5
0.5
-0.5
VOUT ≈VSUP
response with RSUP= 1kΩ is much faster than RSUP
=
VOUT ≈ 2V
10kΩ. The maximum cathode current of IMIN is 0.7mA,
any cathode current below this value will cause a low
response (low open-loop gain) for the application of
comparator.
VIN
-1
-0.6
-0.2
0.2
0.6
1
The overdrive voltage is defined as the voltage over the
internal reference voltage (2.5V). If the overdrive
voltage is not large enough, the output response will be
Time (ms)
Figure 4. Output Response with Various Cathode Current
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LM431BQ
Precision Programmable Reference
APPLICATION INFORMATION (continued)
Total Accuracy
Shunt Regulator/Reference
When the output voltage is set higher than unity gain
(2.5V), the behavior of the LM431BQ will be influenced
by the following possible errors:
RSUP
VSUP
VOUT
R1
0.1%
CATHODE
ANODE
The accuracy of both R1 and R2.
REF
VREF
CL
The internal reference voltage will be changed by the
temperature.
R2
0.1%
LM431BQ
ΔVREF/ΔVKA: The change of internal reference voltage
will affect the output voltage.
|ZKA|: This impedance will be affected by the cathode
current.
R
1
VOUT = VREF × 1 +
R2
The above possible errors are the worst cases for the
operation of the LM431BQ.
Figure 5. Shunt Regulator Schematic
As shown in Figure 5, for this design, the input
parameters are listed in Table 2.
Stability
For traditional 431 devices, the reference output
stability is affected by output decoupling capacitor
which must be selected in a limited range in order to
keep 431 devices stable in applications. However, the
LM431BQ is different from the others. The LM431BQ
uses a special design to greatly improve output stability
when it drives capacitive load. From the curve of the
Cathode Current vs. Load Capacitance in Figure 6, the
output of the LM431BQ is stable in a wider range of
capacitive load. If the LM431BQ is used as a linear
regulator, a bigger decoupling capacitor can be used to
improve regulator's load transient or reduce the noise
of power supply. If the LM431BQ is used to replace the
others, the LM431BQ will be stable and there is no
need to change the output decoupling capacitor in the
original design.
Table 2. Design Parameters
Design Parameter
Supply Voltage
Cathode Current (IKA
Example Value
40V
)
5mA
Output Voltage Range
Load Capacitance
2.5V to 36V
100nF
Feedback Resistor Values and
Accuracy (R1 and R2)
10kΩ (0.1%)
Programming Output Voltage
The output/cathode voltage of the LM431BQ is
programmed by resistor R1 and R2. The following
equation shows the relationship between VREF and VOUT
In accurate applications, the error caused by IREF
should also be taken into account:
.
100
R
1
VOUT = VREF
×
1 +
+ IREF × R1
R2
80
And the users need to ensure that the LM431BQ is fully
biased, so that this error can be decreased significantly
by the enough open-loop gain. This can be qualified by
satisfying the minimum cathode current IMIN in Electrical
Characteristics.
60
Stable
40
20
0
0.0001 0.001 0.01 0.1
1
10
100 1000
Load Capacitance (μF)
Figure 6. Cathode Current vs. Load Capacitance
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LM431BQ
Precision Programmable Reference
APPLICATION INFORMATION (continued)
Start-Up Time
As shown in Figure 7, the LM431BQ is suitable for
many clamp applications with the fast response.
Power Supply Recommendations
When the LM431BQ is used as a shunt regulator, it is
necessary to use a bypass capacitor on the CATHODE
pin.
27
R1 = 10kΩ, R2 = 10kΩ
R1 = 38kΩ, R2 = 10kΩ
24
Limiting the current of the power supply is necessary
for the LM431BQ to operate within the maximum
cathode current. Also, the current of the REF pin should
be limited as well.
21
VSUP
18
15
12
9
When the device shunts high current, adjusting the
width and length of traces on the CATHODE pin and
ANODE pin is necessary in the PCB board to have a
proper density of current.
6
3
0
VKA = VREF
-3
-6
Layout
-25 -20 -15 -10 -5
0
5
10 15 20 25
Please make sure that the bypass capacitor is close
enough to the part. The width of trace on the PCB
should be fit for its amount of current flowing. For the
LM431BQ, these currents will not be large.
Time (μs)
Figure 7. LM431BQ Start-Up Response
REVISION HISTORY
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
JUNE 2022 ‒ REV.A to REV.A.1
Page
Updated Application Information section..............................................................................................................................................................8
Changes from Original (MARCH 2022) to REV.A
Page
Changed from product preview to production data.............................................................................................................................................All
SG Micro Corp
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JUNE 2022
9
PACKAGE INFORMATION
PACKAGE OUTLINE DIMENSIONS
SOT-23
D
b
2.29
E1
E
0.76
0.76
e
e1
0.95
RECOMMENDED LAND PATTERN (Unit: mm)
L1
L
A
A1
c
θ
A2
0.25
Dimensions
In Millimeters
Dimensions
In Inches
Symbol
MIN
MAX
1.12
0.10
1.02
0.50
0.20
3.04
1.40
2.64
MIN
MAX
0.044
0.004
0.040
0.020
0.008
0.120
0.055
0.104
A
A1
A2
b
0.89
0.01
0.88
0.30
0.08
2.80
1.20
2.10
0.035
0.000
0.035
0.012
0.003
0.110
0.047
0.083
c
D
E
E1
e
0.95 BSC
1.90 BSC
0.54 REF
0.037 BSC
0.075 BSC
0.021 REF
e1
L
L1
θ
0.40
0°
0.60
8°
0.016
0°
0.024
8°
NOTES:
1. Body dimensions do not include mode flash or protrusion.
2. This drawing is subject to change without notice.
SG Micro Corp
TX00031.001
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PACKAGE INFORMATION
TAPE AND REEL INFORMATION
REEL DIMENSIONS
TAPE DIMENSIONS
P2
P0
W
Q2
Q4
Q2
Q4
Q2
Q4
Q1
Q3
Q1
Q3
Q1
Q3
B0
Reel Diameter
P1
A0
K0
Reel Width (W1)
DIRECTION OF FEED
NOTE: The picture is only for reference. Please make the object as the standard.
KEY PARAMETER LIST OF TAPE AND REEL
Reel Width
Reel
Diameter
A0
B0
K0
P0
P1
P2
W
Pin1
Package Type
W1
(mm)
(mm) (mm) (mm) (mm) (mm) (mm) (mm) Quadrant
SOT-23
7″
9.5
3.15
2.77
1.22
4.0
4.0
2.0
8.0
Q3
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TX10000.000
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PACKAGE INFORMATION
CARTON BOX DIMENSIONS
NOTE: The picture is only for reference. Please make the object as the standard.
KEY PARAMETER LIST OF CARTON BOX
Length
(mm)
Width
(mm)
Height
(mm)
Reel Type
Pizza/Carton
7″ (Option)
7″
368
442
227
410
224
224
8
18
SG Micro Corp
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TX20000.000
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