LM4040/4041
Micrel, Inc.
LM4040/4041
Precision Micropower Shunt Voltage Reference
General Description
Ideal for space critical applications, the LM4040 and LM4041
precision voltage references are available in the subminiature
(3mm
×
1.3mm) SOT-23 surface-mount package.
The LM4040 is the available in fixed reverse breakdown
voltages of 2.500V, 4.096V and 5.000V. The LM4041 is avail-
able with a fixed 1.225V or an adjustable reverse breakdown
voltage.
The minimum operating current ranges from 60µA for the
LM4041-1.2 to 74µA for the LM4040-5.0. LM4040 versions
have a maximum operating current of 15mA. LM4041 ver-
sions have a maximum operating current of 12mA.
The LM4040 and LM4041 have bandgap reference tempera-
ture drift curvature correction and low dynamic impedance,
ensuring stable reverse breakdown voltage accuracy over a
wide range of operating temperatures and currents.
Data sheets and support documentation can be found on
Micrel’s web site at www.micrel.com.
Features
•
•
•
•
Small SOT-23 package
No output capacitor required
Tolerates capacitive loads
Fixed reverse breakdown voltages of 1.225, 2.500V,
4.096V and 5.000V
• Adjustable reverse breakdown version
• Contact Micrel for parts with extended temperature
range.
Key Specifications
• Output voltage tolerance ............................. ±0.1% (max)
• Low output noise (10Hz to 100Hz)
LM4040 ................................................. 35µV
RMS
(typ)
LM4041 ................................................. 20µV
RMS
(typ)
• Wide operating current range
LM4040 ..................................................60µA to 15mA
LM4041 ..................................................60µA to 12mA
• Industrial temperature range .................. –40°C to +85°C
• Low temperature coefficient ................ 100ppm/°C (max)
Applications
•
•
•
•
•
•
•
•
Battery-powered equipment
Data acquisition systems
Instrumentation
Process control
Energy management
Product testing
Automotive electronics
Precision audio components
Typical Applications
V
S
V
S
R
S
V
R
LM4040
LM4041
I
Q
+ I
L
I
L
I
Q
R
S
V
O
V
O
LM4041
Adjustable
R
1
V
O
= 1.233 (R
2
/R
1
+ 1)
R
2
Figure 1. LM4040, LM4041 Fixed
Shunt Regulator Application
Figure 2. LM4041 Adjustable
Shunt Regulator Application
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
March 2005
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M9999-031805
LM4040/4041
Micrel, Inc.
Pin Configuration
FB
3
+
1
3–
2
Pin 3 must float or be
connected to pin 2.
Fixed Version
SOT-23 (M3) Package
Adjustable Version
SOT-23 (M3) Package
Ordering Information
Standard
Part Number
Pb-Free
LM4040CYM3-2.5
LM4040DYM3-2.5
LM4040CYM3-4.1
LM4040DYM3-4.1
LM4040CYM3-5.0
LM4040DYM3-5.0
LM4041CYM3-1.2
LM4041DYM3-1.2
LM4041CYM3-ADJ
LM4041DYM3-ADJ
Voltage
2.500V
2.500V
4.096V
4.096V
5.000V
5.000V
1.225V
1.225V
1.24V to 10V
1.24V to 10V
Accuracy,
Temp. Coefficient
±0.5%, 100ppm/°C
±1.0%, 150ppm/°C
±0.5%, 100ppm/°C
±1.0%, 150ppm/°C
±0.5%, 100ppm/°C
±1.0%, 150ppm/°C
±0.5%, 100ppm/°C
±1.0%, 150ppm/°C
±0.5%, 100ppm/°C
±1.0%, 150ppm/°C
LM4040CIM3-2.5
LM4040DIM3-2.5
LM4040CIM3-4.1
LM4040DIM3-4.1
LM4040CIM3-5.0
LM4040DIM3-5.0
LM4041CIM3-1.2
LM4041DIM3-1.2
LM4041CIM3-ADJ
LM4041DIM3-ADJ
SOT-23 Package Markings
Example
R__
Y__
Field
Code
1st Character
1st Character
R = Reference
Y = Pb-Free
Example
_2_
Field
Code
Example
__C
Field
Code
2nd Character 1 = 1.225V
2 = 2.500V
4 = 4.096V
5 = 5.000V
A = Adjustable
3rd Character C = ±0.5%
D = ±1.0%
X = ±0.5% Pb-Free
Y = ±1.0% Pb-Free
Example:
R2C represents
Reference, 2.500V,
±0.5%
(LM4040CIM3-2.5)
Example:
Y1C represents
Pb-Free, 1.225V,
±0.5%
(LM4040CYM3-1.2)
Note:
If 3rd character is omitted, container will
indicate tolerance.
M9999-031805
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March 2005
LM4040/4041
Micrel, Inc.
+
+
V
REF
FB
Functional Diagram
LM4040, LM4041 Fixed
Functional Diagram
LM4041 Adjustable
Absolute Maximum Ratings
Reverse Current ......................................................... 20mA
Forward Current ......................................................... 10mA
Maximum Output Voltage
LM4041-Adjustable.................................................... 15V
Power Dissipation at T
A
= 25°C (Note
2)
................ 306mW
Storage Temperature ................................ –65°C to +150°C
Lead Temperature
Vapor phase (60 seconds) ............................... +215°C
Infrared (15 seconds)....................................... +220°C
ESD Susceptibility
Human Body Model (Note
3)
............................... 2kV
Machine Model (Note
3)
.................................... 200V
Note 1.
Operating Ratings
(Notes 1 and 2)
Temperature Range
(T
MIN
≤ T
A
≤ T
MAX
) ............................–40°C ≤ T
A
≤ +85°C
Reverse Current
LM4040-2.5............................................ 60µA to 15mA
LM4040-4.1............................................ 68µA to 15mA
LM4040-5.0............................................ 74µA to 15mA
LM4041-1.2............................................ 60µA to 12mA
LM4041-ADJ .......................................... 60µA to 12mA
Output Voltage Range
LM4041-ADJ ............................................1.24V to 10V
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 specification 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.
The maximum power dissipation must be derated at elevated temperatures and is dictated by T
JMAX
(maximum junction temperature),
θ
JA
(junction to ambient thermal resistance), and T
A
(ambient temperature). The maximum allowable power dissipation at any temperature is PD-
MAX
= (T
JMAX
– T
A
)/θ
JA
or the number given in the Absolute Maximum Ratings, whichever is lower. For the LM4040 and LM4041,
T
JMAX
= 125°C, and the typical thermal resistance (θ
JA
), when board mounted, is 326°C/W for the SOT-23 package.
The human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin. The machine model is a 200pF capacitor
discharged directly into each pin.
Note 2.
Note 3.
March 2005
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M9999-031805
LM4040/4041
Micrel, Inc.
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 and D designate initial Reverse Break-
down Voltage tolerance of ±0.5% and ±1.0 respectively.
Symbol
Parameter
Conditions
(Note 5)
I
R
= 100µA
Typical
Limits
2.500
±12
±29
45
60
65
±100
±25
±49
65
70
±150
LM4040CIM3
(Note 6)
Limits
LM4040DIM3
(Limit)
(Note 6)
Units
LM4040-2.5 Electrical Characteristics
(Note 4)
V
R
Reverse Breakdown Voltage
Reverse Breakdown Voltage
Tolerance
(Note 7)
Minimum Operating Current
V
mV (max)
mV (max)
µA
µA (max)
µA (max)
ppm/°C
ppm/°C (max)
ppm/°C (max)
mV
mV (max)
mV (max)
mV
mV (max)
mV (max)
Ω
Ω (max)
µV
RMS
ppm
I
R
= 100µA
I
RMIN
ΔV
R
/ΔT
ΔV
R
/ΔI
R
Average Reverse Breakdown
Voltage Temperature
Coefficient
Reverse Breakdown Voltage
Change with Operating
Current Change
I
RMIN
≤ I
R
1mA
1mA ≤ I
R
15mA
I
R
= 10mA
I
R
= 1mA
I
R
= 100µA
±20
±15
±15
0.3
0.8
1.0
6.0
8.0
0.9
1.0
1.2
8.0
10.0
1.1
2.5
Z
R
e
N
ΔV
R
Reverse Dynamic Impedance
Wideband Noise
Reverse Breakdown Voltage
Long Term Stability
I
R
= 100µA
10Hz ≤ f ≤ 10kHz
t = 1000hrs
T = 25°C ±0.1°C
I
R
= 100µA
I
R
= 1mA, f = 120Hz
I
AC
= 0.1 I
R
0.3
35
120
Note 4.
Note 5.
Note 6.
Note 7.
Specification for packaged product only.
Typicals are at T
J
= 25°C and represent most likely parametric norm.
Limits are 100% production tested at 25°C. Limits over temperature are guaranteed through correlation using Statistical Quality Control (SQL)
methods.
The boldface (over temperature limit for Reverse Breakdown Voltage Tolerance is defined as the room temperature Reverse Breakdown Volt-
age Tolerance ±[(ΔV
R
/ΔT)(65°C)(V
R
)]. ΔV
R
/ΔT is the V
R
temperature coefficient, 65°C is the temperature range from –40°C to the reference
point of 25°C, and V
R
is the reverse breakdown voltage. The total over temperature tolerance for the different grades follows:
C-grade: ±1.15% = ±0.5% ±100ppm/°C
×
65°C
D-grade: ±1.98% = ±1.0% ±150ppm/°C
×
65°C
Example: The C-grade LM4040-2.5 has an over temperature Reverse Breakdown Voltage tolerance of ±2.5
×
1.15% = ±29mV.
M9999-031805
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March 2005
LM4040/4041
Micrel, Inc.
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 and D designate initial Reverse Break-
down Voltage tolerance of ±0.5% and ± 1.0% respectively.
Symbol
Parameter
Conditions
Typical
(Note 5)
(Note 6)
4.096
±20
±47
50
68
73
±100
±41
±81
73
78
±150
LM4040CIM3
Limits
(Note 6)
LM4040DIM3
Limits
Units
(Limits)
V
mV (max)
mV (max)
µA
µA (max)
µA (max)
ppm/°C
ppm/°C (max)
ppm/°C (max)
mV
mV (max)
mV (max)
mV
mV (max)
mV (max)
Ω
Ω (max)
µV
RMS
ppm
LM4040-4.1 Electrical Characteristics
(Note 4)
V
R
Reverse Breakdown Voltage
Reverse Breakdown Voltage
Tolerance
(Note 7)
Minimum Operating Current
I
R
= 100µA
I
R
= 100µA
I
RMIN
ΔV
R
/ΔT
ΔV
R
/ΔI
R
Average Reverse Breakdown
Voltage Temperature
Coefficient
Reverse Breakdown Voltage
Change with Operating
Current Change
I
RMIN
≤ I
R
1mA
1mA ≤ I
R
15mA
I
R
= 10mA
I
R
= 1mA
I
R
= 100µA
±30
±20
±20
0.5
0.9
1.2
7.0
10.0
1.0
1.2
1.5
9.0
13.0
1.3
3.0
Z
R
e
N
ΔV
R
Reverse Dynamic Impedance
Wideband Noise
Reverse Breakdown Voltage
Long Term Stability
I
R
= 100µA
10Hz ≤ f ≤ 10kHz
t = 1000hrs
T = 25°C ±0.1°C
I
R
= 100µA
I
R
= 1mA, f = 120Hz
I
AC
= 0.1 I
R
0.5
80
120
Note 4.
Note 5.
Note 6.
Note 7.
Specification for packaged product only.
Typicals are at T
J
= 25°C and represent most likely parametric norm.
Limits are 100% production tested at 25°C. Limits over temperature are guaranteed through correlation using Statistical Quality Control (SQL)
methods.
The boldface (over temperature limit for Reverse Breakdown Voltage Tolerance is defined as the room temperature Reverse Breakdown Volt-
age Tolerance ±[(ΔV
R
/ΔT)(65°C)(V
R
)]. ΔV
R
/ΔT is the V
R
temperature coefficient, 65°C is the temperature range from –40°C to the reference
point of 25°C, and V
R
is the reverse breakdown voltage. The total over temperature tolerance for the different grades follows:
C-grade: ±1.15% = ±0.5% ±100ppm/°C
×
65°C
D-grade: ±1.98% = ±1.0% ±150ppm/°C
×
65°C
Example: The C-grade LM4040-2.5 has an over temperature Reverse Breakdown Voltage tolerance of ±2.5
×
1.15% = ±29mV.
March 2005
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