LM4041
LM4041 Precision Micropower Shunt Voltage Reference
Literature Number: SNOS641D
LM4041
Precision Micropower Shunt Voltage Reference
General Description
Ideal for space critical applications, the LM4041 precision
voltage reference is available in the sub-miniature SC70 and
SOT-23 surface-mount packages. The LM4041’s advanced
design eliminates the need for an external stabilizing capaci-
tor while ensuring stability with any capacitive load, thus
making the LM4041 easy to use. Further reducing design
effort is the availability of a fixed (1.225V) and adjustable
reverse breakdown voltage. The minimum operating current
is 60 µA for the LM4041-1.2 and the LM4041-ADJ. Both
versions have a maximum operating current of 12 mA.
The LM4041 utilizes fuse and zener-zap reverse breakdown
or reference voltage trim during wafer sort to ensure that the
prime parts have an accuracy of better than ±0.1%
(A grade) at 25˚C. Bandgap reference temperature drift cur-
vature correction and low dynamic impedance ensure stable
reverse breakdown voltage accuracy over a wide range of
operating temperatures and currents.
Features
nSmall packages: SOT-23, TO-92, and SC70
nNo output capacitor required
nTolerates capacitive loads
nReverse breakdown voltage options of 1.225V and
adjustable
Key Specifications (LM4041-1.2)
jOutput voltage tolerance
(A grade, 25˚C) ±0.1%(max)
jLow output noise
(10 Hz to 10kHz) 20µV
rms
jWide operating current range 60µA to 12mA
jIndustrial temperature range −40˚C to +85˚C
jExtended temperature range −40˚C to +125˚C
jLow temperature coefficient 100 ppm/˚C (max)
Applications
nPortable, Battery-Powered Equipment
nData Acquisition Systems
nInstrumentation
nProcess Control
nEnergy Management
nAutomotive
nPrecision Audio Components
Connection Diagrams
SOT-23
01139201
*This pin must be left floating or connected to pin 2.
01139240
Top View
See NS Package Number MF03A
(JEDEC Registration TO-236AB)
SC-70
01139246
*This pin must be left floating or connected to pin 1.
01139247
Top View
See NS Package Number MAA05A
March 2005
LM4041 Precision Micropower Shunt Voltage Reference
© 2005 National Semiconductor Corporation DS011392 www.national.com
Connection Diagrams (Continued)
TO-92
01139203 01139232
Bottom View
See NS Package Number Z03A
Ordering Information
Reverse
Breakdown
Voltage
Tolerance at 25˚C
and Average
Reverse
Breakdown
Voltage
Temperature
Coefficient
Package
NS
Package
Number
M3 (SOT-23) M7 (SC70) Z (TO-92)
Supplied as 1000
Units Tape and
Reel
Supplied as 3000
Units Tape and
Reel
Supplied as 1000
Units Tape and
Reel
Supplied as 3000
Units Tape and
Reel
±0.1%, 100
ppm/˚C max (A
grade)
LM4041AIM3-1.2 LM4041AIM3X-1.2 LM4041AIZ-1.2 MF03A,
Z03A
±0.2%, 100
ppm/˚C max (B
grade)
LM4041BIM3-1.2 LM4041BIM3X-1.2 LM4041BIM7-1.2 LM4041BIM7X-1.2 LM4041BIZ-1.2 MF03A,
Z03A,
MAA05A
±0.5%, 100
ppm/˚C max (C
grade)
LM4041CEM3-1.2
LM4041CIM3-1.2
LM4041CEM3-ADJ
LM4041CIM3-ADJ
LM4041CEM3X-1.2
LM4041CIM3X-1.2
LM4041CEM3X-ADJ
LM4041CIM3X-ADJ
LM4041CIM7-1.2
LM4041CIM7-ADJ
LM4041CIM7X-1.2
LM4041CIM7X-ADJ
LM4041CIZ-1.2
LM4041CIZ-ADJ
MF03A,
Z03A,
MAA05A
±1.0%, 150
ppm/˚C max (D
grade)
LM4041DEM3-1.2
LM4041DIM3-1.2
LM4041DEM3-ADJ
LM4041DIM3-ADJ
LM4041DEM3X-1.2
LM4041DIM3X-1.2
LM4041DEM3X-ADJ
LM4041DIM3X-ADJ
LM4041DIM7-1.2
LM4041DIM7-ADJ
LM4041DIM7X-1.2
LM4041DIM7X-ADJ
LM4041DIZ-1.2
LM4041DIZ-ADJ
MF03A,
Z03A,
MAA05A
±2.0%, 150
ppm/˚C max (E
grade)
LM4041EEM3-1.2
LM4041EIM3-1.2
LM4041EEM3X-1.2
LM4041EIM3X-1.2
LM4041EIM7-1.2 LM4041EIM7X-1.2 LM4041EIZ-1.2 MF03A,
Z03A,
MAA05A
LM4041
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SOT-23 and SC70 Package Marking Information
Only three fields of marking are possible on the SOT-23’s and SC70’s small surface. This table gives the meaning of the three
fields.
Part Marking Field Definition
R1A (SOT-23 Only) First Field:
R1B R = Reference
R1C Second Field:
R1D 1 = 1.225V Voltage Option
R1E A = Adjustable
Third Field:
RAC A–E = Initial Reverse Breakdown
RAD Voltage or Reference Voltage Tolerance
A=±0.1%, B = ±0.2%, C = ±0.5%, D = ±1.0%, E = ±2.0%
LM4041
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Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Reverse Current 20 mA
Forward Current 10 mA
Maximum Output Voltage
(LM4041-ADJ) 15V
Power Dissipation (T
A
= 25˚C) (Note 2)
M3 Package 306 mW
Z Package 550 mW
M7 Package 241mW
Storage Temperature −65˚C to +150˚C
Lead Temperature
M3 Packages
Vapor phase (60 seconds) +215˚C
Infrared (15 seconds) +220˚C
Z Package
Soldering (10 seconds) +260˚C
ESD Susceptibility
Human Body Model (Note 3) 2 kV
Machine Model (Note 3) 200V
See AN-450 “Surface Mounting Methods and Their Effect
on Product Reliability” for other methods of soldering
surface mount devices.
Operating Ratings(Notes 1, 2)
Temperature Range (T
min
T
A
T
max
)
Industrial Temperature Range −40˚C T
A
+85˚C
Extended Temperature Range −40˚C T
A
+125˚C
Reverse Current
LM4041-1.2 60 µA to 12 mA
LM4041-ADJ 60 µA to 12 mA
Output Voltage Range
LM4041-ADJ 1.24V to 10V
LM4041-1.2
Electrical Characteristics (Industrial Temperature Range)
Boldface limits apply for T
A
=T
J
=T
MIN
to T
MAX
;all other limits T
A
=T
J
= 25˚C. The grades A and B designate initial Re-
verse Breakdown Voltage tolerances of ±0.1% and ±0.2%, respectively.
Symbol Parameter Conditions Typical
(Note 4)
LM4041AIM3
LM4041AIZ
Limits
(Note 5)
LM4041BIM3
LM4041BIZ
LM4041BIM7
Limits
(Note 5)
Units
(Limit)
V
R
Reverse Breakdown Voltage I
R
= 100 µA 1.225 V
Reverse Breakdown Voltage I
R
= 100 µA ±1.2 ±2.4 mV (max)
Tolerance (Note 6) ±9.2 ±10.4 mV (max)
I
RMIN
Minimum Operating Current 45 µA
60 60 µA (max)
65 65 µA (max)
V
R
/T Average Reverse Breakdown
Voltage Temperature
Coefficient (Note 6)
I
R
=10mA ±20 ppm/˚C
I
R
=1mA ±15 ±100 ±100 ppm/˚C (max)
I
R
= 100 µA ±15 ppm/˚C
V
R
/I
R
Reverse Breakdown Voltage
Change with Operating
Current Change
(Note 9)
I
RMIN
I
R
1 mA 0.7 mV
1.5 1.5 mV (max)
2.0 2.0 mV (max)
1mAI
R
12 mA 4.0 mV
6.0 6.0 mV (max)
8.0 8.0 mV (max)
Z
R
Reverse Dynamic Impedance I
R
= 1 mA, f = 120 Hz, 0.5
I
AC
= 0.1 I
R
1.5 1.5 (max)
e
N
Wideband Noise I
R
= 100 µA 20 µV
rms
10 Hz f10 kHz
V
R
Reverse Breakdown Voltage
Long Term Stability
t = 1000 hrs
T = 25˚C ±0.1˚C 120 ppm
I
R
= 100 µA
V
HYST
Thermal Hysteresis
(Note 10)
T = −40˚C to +125˚C 0.08 %
LM4041
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LM4041-1.2
Electrical Characteristics (Industrial Temperature Range) (Continued)
LM4041-1.2
Electrical Characteristics (Industrial Temperature Range)
Boldface limits apply for T
A
=T
J
=T
MIN
to T
MAX
;all other limits T
A
=T
J
= 25˚C. The grades C, D and E designate initial Re-
verse Breakdown Voltage tolerances of ±0.5%, ±1.0% and ±2.0%, respectively.
Symbol Parameter Conditions Typical
(Note 4)
LM4041CIM3
LM4041CIZ
LM4041CIM7
Limits
(Note 5)
LM4041DIM3
LM4041DIZ
LM4041DIM7
Limits (Note
5)
LM4041EIM3
LM4041EIZ
LM4041EIM7
Limits
(Note 5)
Units
(Limit)
V
R
Reverse Breakdown
Voltage
I
R
= 100 µA 1.225 V
Reverse Breakdown
Voltage
I
R
= 100 µA ±6±12 ±25 mV (max)
Tolerance (Note 6) ±14 ±24 ±36 mV (max)
I
RMIN
Minimum Operating
Current
45 µA
60 65 65 µA (max)
65 70 70 µA (max)
V
R
/TV
R
Temperature
Coefficient (Note 6)
I
R
=10mA ±20 ppm/˚C
I
R
=1mA ±15 ±100 ±150 ±150 ppm/˚C (max)
I
R
= 100 µA ±15 ppm/˚C
V
R
/I
R
Reverse Breakdown
Voltage Change with
Operating Current
Change
(Note 9)
I
RMIN
I
R
1 mA 0.7 mV
1.5 2.0 2.0 mV (max)
2.0 2.5 2.5 mV (max)
1mAI
R
12 mA 2.5 mV
6.0 8.0 8.0 mV (max)
8.0 10.0 10.0 mV (max)
Z
R
Reverse Dynamic
Impedance
I
R
= 1 mA, f = 120 Hz 0.5
I
AC
= 0.1 I
R
1.5 2.0 2.0 (max)
e
N
Wideband Noise I
R
= 100 µA 20 µV
rms
10 Hz f10 kHz
V
R
Reverse Breakdown
Voltage Long Term
Stability
t = 1000 hrs
T = 25˚C ±0.1˚C 120 ppm
I
R
= 100 µA
V
HYST
Thermal Hysteresis
(Note 10)
T = −40˚C to +125˚C 0.08 %
LM4041
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LM4041-1.2
Electrical Characteristics (Extended Temperature Range)
Boldface limits apply for T
A
=T
J
=T
MIN
to T
MAX
;all other limits T
A
=T
J
= 25˚C. The grades C, D and E designate initial Re-
verse Breakdown Voltage tolerance of ±0.5%, ±1.0% and ±2.0% respectively.
Symbol Parameter Conditions Typical
(Note 4)
LM4041CEM3
Limits
(Note 5)
LM4041DEM3
Limits
(Note 5)
LM4041EEM3
Limits
(Note 5)
Units
(Limit)
V
R
Reverse Breakdown
Voltage
I
R
= 100 µA 1.225 V
Reverse Breakdown
Voltage Error
I
R
= 100 µA ±6±12 ±25 mV (max)
(Note 6) ±18.4 ±31 ±43 mV (max)
I
RMIN
Minimum Operating
Current
45 µA
60 65 65 µA (max)
68 73 73 µA (max)
V
R
/T VR Temperature
Coefficient(Note 6)
I
R
=10mA ±20 ppm/˚C
I
R
=1mA ±15 ±100 ±150 ±150 ppm/˚C
(max)
I
R
= 100 µA ±15 ppm/˚C
V
R
/I
R
Reverse Breakdown
Change with
Current
(Note 9)
I
RMIN
I
R
1.0 mA 0.7 mV
1.5 2.0 2.0 mV (max)
2.0 2.5 2.5 mV (max)
1mAI
R
12 mA 2.5 mV
6.0 8.0 8.0 mV (max)
8.0 10.0 10.0 mV (max)
Z
R
Reverse Dynamic
Impedance
I
R
= 1 mA, f = 120 Hz, 0.5
I
AC
= 0.1 I
R
1.5 2.0 2.0 (max)
e
N
Noise Voltage I
R
= 100 µA 20 µV
rms
10 Hz f10 kHz
V
R
Long Term Stability
(Non-Cumulative)
t = 1000 hrs
T = 25˚C ±0.1˚C 120 ppm
I
R
= 100 µA
V
HYST
Thermal Hysteresis
(Note 10)
T = −40˚C to +125˚C 0.08 %
LM4041
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LM4041-ADJ (Adjustable)
Electrical Characteristics (Industrial Temperature Range)
Boldface limits apply for T
A
=T
J
=T
MIN
to T
MAX
;all other limits T
J
= 25˚C unless otherwise specified (SOT-23, see (Note
7)), I
RMIN
I
R
12 mA, V
REF
V
OUT
10V. The grades C and D designate initial Reference Voltage Tolerances of ±0.5%
and ±1%, respectively for V
OUT
= 5V.
Symbol Parameter Conditions Typical
(Note 4)
LM4041CIM3
LM4041CIZ
LM4041CIM7
(Note 5)
LM4041DIM3
LM4041DIZ
LM4041DIM7
(Note 5)
Units
(Limit)
V
REF
Reference Voltage I
R
= 100 µA, V
OUT
= 5V 1.233 V
Reference Voltage I
R
= 100 µA, V
OUT
=5V ±6.2 ±12 mV (max)
Tolerance (Note 8) ±14 ±24 mV (max)
I
RMIN
Minimum Operating
Current
45 µA
60 65 µA (max)
65 70 µA (max)
V
REF
/I
R
Reference Voltage
Change with Operating
Current Change
(Note 9)
I
RMIN
I
R
1 mA 0.7 mV
SOT-23: V
OUT
1.6V 1.5 2.0 mV (max)
(Note 7) 2.0 2.5 mV (max)
1mAI
R
12 mA 2 mV
SOT-23: V
OUT
1.6V (Note 7) 4 6 mV (max)
68mV (max)
V
REF
/V
O
Reference Voltage
Change
with Output Voltage
Change
I
R
= 1 mA −1.55 mV/V
−2.0 −2.5 mV/V (max)
−2.5 −3.0 mV/V (max)
I
FB
Feedback Current 60 nA
100 150 nA (max)
120 200 nA (max)
V
REF
/T Average Reference
Voltage Temperature
Coefficient (Note 8)
V
OUT
= 5V, I
R
= 10 mA 20 ppm/˚C
I
R
= 1 mA 15 ±100 ±150 ppm/˚C (max)
I
R
= 100 µA 15 ppm/˚C
Z
OUT
Dynamic Output
Impedance
I
R
= 1 mA, f = 120 Hz,
I
AC
= 0.1 I
R
V
OUT
=V
REF
0.3
V
OUT
= 10V 2
e
N
Wideband Noise I
R
= 100 µA V
OUT
=V
REF
20 µV
rms
10 Hz f10 kHz
V
REF
Reference Voltage Long t = 1000 hrs, I
R
= 100 µA 120 ppm
Term Stability T = 25˚C ±0.1˚C
V
HYST
Thermal Hysteresis
(Note 10)
T = −40˚C to +125˚C 0.08 %
LM4041
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LM4041-ADJ (Adjustable)
Electrical Characteristics (Extended Temperature Range)
Boldface limits apply for T
A
=T
J
=T
MIN
to T
MAX
;all other limits T
J
= 25˚C unless otherwise specified (SOT-23, see (Note
7)), I
RMIN
I
R
12 mA, V
REF
V
OUT
10V. The grades C and D designate initial Reference Voltage Tolerances of ±0.5%
and ±1%, respectively for V
OUT
= 5V.
Symbol Parameter Conditions Typical
(Note 4)
LM4041CEM3
(Note 5)
LM4041DEM3
(Note 5)
Units
(Limit)
V
REF
Reference Voltage I
R
= 100 µA, V
OUT
= 5V 1.233 V
Reference Voltage I
R
= 100 µA, V
OUT
=5V ±6.2 ±12 mV (max)
Tolerance (Note 8) ±18 ±30 mV (max)
I
RMIN
Minimum Operating
Current
45 µA
60 65 µA (max)
68 73 µA (max)
V
REF
/I
R
Reference Voltage
Change with Operating
Current Change
(Note 9)
I
RMIN
I
R
1 mA 0.7 mV
SOT-23: V
OUT
1.6V 1.5 2.0 mV (max)
(Note 7) 2.0 2.5 mV (max)
1mAI
R
12 mA 2 mV
SOT-23: V
OUT
1.6V(Note 7) 8 10 mV (max)
68mV (max)
V
REF
/V
O
Reference Voltage
Change
with Output Voltage
Change
I
R
= 1 mA −1.55 mV/V
−2.0 −2.5 mV/V (max)
−3.0 −4.0 mV/V (max)
I
FB
Feedback Current 60 nA
100 150 nA (max)
120 200 nA (max)
V
REF
/T Average Reference
Voltage Temperature
Coefficient (Note 8)
V
OUT
= 5V, I
R
= 10 mA 20 ppm/˚C
I
R
= 1 mA 15 ±100 ±150 ppm/˚C (max)
I
R
= 100 µA 15 ppm/˚C
Z
OUT
Dynamic Output
Impedance
I
R
= 1 mA, f = 120 Hz,
I
AC
= 0.1 I
R
V
OUT
=V
REF
0.3
V
OUT
= 10V 2
e
N
Wideband Noise I
R
= 100 µA V
OUT
=V
REF
20 µV
rms
10 Hz f10 kHz
V
REF
Reference Voltage Long t = 1000 hrs, I
R
= 100 µA 120 ppm
Term Stability T = 25˚C ±0.1˚C
V
HYST
Thermal Hysteresis
(Note 10)
T = −40˚C to +125˚C 0.08 %
LM4041
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LM4041-ADJ (Adjustable)
Electrical Characteristics (Extended Temperature Range) (Continued)
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. The guaranteed
specifications apply only for the test conditions listed. Some performance characteristics may degrade when the device is not operated under the listed test
conditions.
Note 2: The maximum power dissipation must be derated at elevated temperatures and is dictated by TJmax (maximum junction temperature), θJA (junction to
ambient thermal resistance), and TA(ambient temperature). The maximum allowable power dissipation at any temperature is PDmax =(T
Jmax −T
A)/θJA or the
number given in the Absolute Maximum Ratings, whichever is lower. For the LM4041, TJmax = 125˚C, and the typical thermal resistance (θJA), when board mounted,
is 326˚C/W for the SOT-23 package, 415˚C/W for the SC70 package and 180˚C/W with 0.4" lead length and 170˚C/W with 0.125" lead length for the TO-92 package.
Note 3: The human body model is a 100 pF capacitor discharged through a 1.5 kresistor into each pin. The machine model is a 200 pF capacitor discharged
directly into each pin. All pins are rated at 2kV for Human Body Model, but the feedback pin which is rated at 1kV.
Note 4: Typicals are at TJ= 25˚C and represent most likely parametric norm.
Note 5: Limits are 100% production tested at 25˚C. Limits over temperature are guaranteed through correlation using Statistical Quality Control (SQC) methods.
The limits are used to calculate National’s AOQL.
Note 6: The boldface (over-temperature) limit for Reverse Breakdown Voltage Tolerance is defined as the room temperature Reverse Breakdown Voltage Tolerance
±[(VRvT)(max T)(VR)]. Where, VR/T is the VRtemperature coefficient, maxT is the maximum difference in temperature from the reference point of 25 ˚C
to T MAX or TMIN, and VRis the reverse breakdown voltage. The total over-temperature tolerance for the different grades in the industrial temperature range where
maxT=65˚C is shown below:
A-grade: ±0.75% = ±0.1% ±100 ppm/˚C x 65˚C
B-grade: ±0.85% = ±0.2% ±100 ppm/˚C x 65˚C
C-grade: ±1.15% = ±0.5% ±100 ppm/˚C x 65˚C
D-grade: ±1.98% = ±1.0% ±150 ppm/˚C x 65˚C
E-grade: ±2.98% = ±2.0% ±150 ppm/˚C x 65˚C
The total over-temperature tolerance for the different grades in the extended temperature range where max T = 100 ˚C is shown below:
B-grade: ±1.2% = ±0.2% ±100 ppm/˚C x 100˚C
C-grade: ±1.5% = ±0.5% ±100 ppm/˚C x 100˚C
D-grade: ±2.5% = ±1.0% ±150 ppm/˚C x 100˚C
E-grade: ±4.5% = ±2.0% ±150 ppm/˚C x 100˚C
Therefore, as an example, the A-grade LM4041-1.2 has an over-temperature Reverse Breakdown Voltage tolerance of ±1.2V x 0.75% = ±9.2 mV.
Note 7: When VOUT 1.6V, the LM4041-ADJ in the SOT-23 package must operate at reduced IR. This is caused by the series resistance of the die attach between
the die (-) output and the package (-) output pin. See the Output Saturation (SOT-23 only) curve in the Typical Performance Characteristics section.
Note 8: Reference voltage and temperature coefficient will change with output voltage. See Typical Performance Characteristics curves.
Note 9: Load regulation is measured on pulse basis from no load to the specified load current. Ouput changes due to die temperature change must be taken into
account separately.-
Note 10: Thermal hysteresis is defined as the difference in voltage measured at +25˚C after cycling to temperature -40˚C and the 25˚C measurement after cycling
to temperature +125˚C.
LM4041
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Typical Performance Characteristics
Temperature Drift for Different
Average Temperature Coefficient
Output Impedance vs Frequency
01139219 01139204
Noise Voltage Reverse Characteristics and
Minimum Operating Current
01139205 01139209
Start-Up
Characteristics
01139207
01139208
LM4041
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Typical Performance Characteristics (Continued)
Reference Voltage vs Output
Voltage and Temperature
Reference Voltage vs Temperature
and Output Voltage
01139211 01139210
Feedback Current vs Output
Voltage and Temperature
Output Saturation
(SOT-23 Only)
01139212 01139233
Output Impedance vs Frequency Output Impedance vs Frequency
01139213 01139214
LM4041
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Typical Performance Characteristics (Continued)
Reverse Characteristics
01139215
01139216
Large Signal Response
01139217
01139218
Functional Block Diagram
01139221
*LM4041-ADJ only
**LM4041-1.2 only
LM4041
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Applications Information
The LM4041 is a precision micro-power curvature-corrected
bandgap shunt voltage reference. For space critical applica-
tions, the LM4041 is available in the sub-miniature SOT-23
and SC70 surface-mount package. The LM4041 has been
designed for stable operation without the need of an external
capacitor connected between the “+” pin and the “−” pin. If,
however, a bypass capacitor is used, the LM4041 remains
stable. Design effort is further reduced with the choice of
either a fixed 1.2V or an adjustable reverse breakdown
voltage. The minimum operating current is 60 µA for the
LM4041-1.2 and the LM4041-ADJ. Both versions have a
maximum operating current of 12 mA.
LM4041s using the SOT-23 package have pin 3 connected
as the (-) output through the package’s die attach interface.
Therefore, the LM4041-1.2’s pin 3 must be left floating or
connected to pin 2 and the LM4041-ADJ’s pin 3 is the (-)
output.
LM4041s using the SC70 package have pin 2 connected as
the (−) output through the packages’ die attach interface.
Therefore, the LM4041-1.2’s pin 2 must be left floating or
connected to pin 1, and the LM4041-ADJ’s pin 2 is the (−)
output.
The typical thermal hysteresis specification is defined as the
change in +25˚C voltage measured after thermal cycling.
The device is thermal cycled to temperature -40˚C and then
measured at 25˚C. Next the device is thermal cycled to
temperature +125˚C and again measured at 25˚C. The re-
sulting V
OUT
delta shift between the 25˚C measurements is
thermal hysteresis. Thermal hysteresis is common in preci-
sion references and is induced by thermal-mechanical pack-
age stress. Changes in environmental storage temperature,
operating temperature and board mounting temperature are
all factors that can contribute to thermal hysteresis.
In a conventional shunt regulator application (Figure 1), an
external series resistor (R
S
) is connected between the sup-
ply voltage and the LM4041. R
S
determines the current that
flows through the load (I
L
) and the LM4041 (I
Q
). Since load
current and supply voltage may vary, R
S
should be small
enough to supply at least the minimum acceptable I
Q
to the
LM4041 even when the supply voltage is at its minimum and
the load current is at its maximum value. When the supply
voltage is at its maximum and I
L
is at its minimum, R
S
should
be large enough so that the current flowing through the
LM4041 is less than 12 mA.
R
S
should be selected based on the supply voltage, (V
S
), the
desired load and operating current, (I
L
and I
Q
), and the
LM4041’s reverse breakdown voltage, V
R
.
The LM4041-ADJ’s output voltage can be adjusted to any
value in the range of 1.24V through 10V. It is a function of the
internal reference voltage (V
REF
) and the ratio of the external
feedback resistors as shown in Figure 2 . The output voltage
is found using the equation
V
O
=V
REF
[(R2/R1) + 1] (1)
where V
O
is the output voltage. The actual value of the
internal V
REF
is a function of V
O
. The “corrected” V
REF
is
determined by
V
REF
=V
O
(V
REF
/V
O
)+V
Y
(2)
where
V
Y
= 1.240 V
and
V
O
=(V
O
−V
Y
)
V
REF
/V
O
is found in the Electrical Characteristics and is
typically −1.55 mV/V. You can get a more accurate indication
of the output voltage by replacing the value of V
REF
in
equation (1) with the value found using equation (2).
Note that the actual output voltage can deviate from that
predicted using the typical value of V
REF
/V
O
in equation
(2): for C-grade parts, the worst-case V
REF
/V
O
is −2.5
mV/V. For D-grade parts, the worst-case V
REF
/V
O
is −3.0
mV/V.
Typical Applications
01139222
FIGURE 1. Shunt Regulator
01139234
V
O
=V
REF
[(R2/R1) + 1]
FIGURE 2. Adjustable Shunt Regulator
LM4041
www.national.com13
Typical Applications (Continued)
01139224
FIGURE 3. Bounded amplifier reduces saturation-induced delays and can prevent succeeding stage damage.
Nominal clamping voltage is ±V
O
(LM4041’s reverse breakdown voltage) +2 diode V
F
.
01139220
FIGURE 4. Voltage Level Detector
01139223
FIGURE 5. Voltage Level Detector
LM4041
www.national.com 14
Typical Applications (Continued)
01139225
FIGURE 6. Fast Positive Clamp
2.4V + V
D1
01139226
FIGURE 7. Bidirectional Clamp ±2.4V
01139235
FIGURE 8. Bidirectional Adjustable
Clamp ±18V to ±2.4V
01139236
FIGURE 9. Bidirectional Adjustable
Clamp ±2.4V to ±6V
LM4041
www.national.com15
Typical Applications (Continued)
Note 11: *D1 can be any LED, VF= 1.5V to 2.2V at 3 mA. D1 may act as an
indicator. D1 will be on if ITHRESHOLDfalls below the threshold current, except
withI=0.
01139237
FIGURE 10. Simple Floating Current Detector
01139238
FIGURE 11. Current Source
LM4041
www.national.com 16
Typical Applications (Continued)
01139239
FIGURE 12. Precision Floating Current Detector
01139228
01139229
FIGURE 13. Precision 1 µA to 1 mA Current Sources
LM4041
www.national.com17
Physical Dimensions inches (millimeters)
unless otherwise noted
Plastic Surface Mount Package (M3)
NS Package Number MF03A
(JEDEC Registration TO-236AB)
Molded Package (SC70)
NS Package Number MAA05A
LM4041
www.national.com 18
Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
Plastic Package (Z)
NS Package Number Z03A
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves
the right at any time without notice to change said circuitry and specifications.
For the most current product information visit us at www.national.com.
LIFE SUPPORT POLICY
NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS
WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR
CORPORATION. As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body, or
(b) support or sustain life, and whose failure to perform when
properly used in accordance with instructions for use
provided in the labeling, can be reasonably expected to result
in a significant injury to the user.
2. A critical component is any component of a life support
device or system whose failure to perform can be reasonably
expected to cause the failure of the life support device or
system, or to affect its safety or effectiveness.
BANNED SUBSTANCE COMPLIANCE
National Semiconductor manufactures products and uses packing materials that meet the provisions of the Customer Products
Stewardship Specification (CSP-9-111C2) and the Banned Substances and Materials of Interest Specification (CSP-9-111S2) and contain
no ‘‘Banned Substances’’ as defined in CSP-9-111S2.
National Semiconductor
Americas Customer
Support Center
Email: new.feedback@nsc.com
Tel: 1-800-272-9959
National Semiconductor
Europe Customer Support Center
Fax: +49 (0) 180-530 85 86
Email: europe.support@nsc.com
Deutsch Tel: +49 (0) 69 9508 6208
English Tel: +44 (0) 870 24 0 2171
Français Tel: +33 (0) 1 41 91 8790
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Asia Pacific Customer
Support Center
Email: ap.support@nsc.com
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Fax: 81-3-5639-7507
Email: jpn.feedback@nsc.com
Tel: 81-3-5639-7560
www.national.com
LM4041 Precision Micropower Shunt Voltage Reference
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