January 2000
1
LM4040/4041
LM4040/4041
Micrel
LM4040/4041
Precision Micropower Shunt Voltage Reference
Final Information
General Description
Ideal for space critical applications, the LM4040 and LM4041
precision voltage references are available in the subminia-
ture (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
available with a fixed 1.225V or an adjustable reverse break-
down voltage.
The LM4040 and LM4041's advanced design eliminates the
need for an external stabilizing capacitor while ensuring
stability with any capacitive load, making them easy to use.
The minimum operating current ranges from 60
A for the
LM4041-1.2 to 74
A for the LM4040-5.0. LM4040 versions
have a maximum operating current of 15mA. LM4041
versions have a maximum operating current of 12mA.
The LM4040 and LM4041 utilizes zener-zap reverse break-
down 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 curvature correc-
tion and low dynamic impedance ensure stable reverse
breakdown voltage accuracy over a wide range of operating
temperatures and currents.
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 (A grade, 25
C) ..
0.1% (max)
Low output noise (10Hz to 100Hz)
LM4040 ................................................ 35
V
RMS
(typ)
LM4041 ................................................ 20
V
RMS
(typ)
Wide operating current range
LM4040 ................................................ 60
A to 15mA
LM4041 ................................................ 60
A 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
R
S
V
R
LM4041
Adjustable
R
1
R
2
V
O
V
S
R
S
V
R
I
Q
+ I
L
I
Q
I
L
LM4040
LM4041
V
O
Figure 2. LM4041 Adjustable
Shunt Regulator Application
Figure 1. LM4040, LM4041 Fixed
Shunt Regulator Application
V
O
= 1.233 (R
2
/R
1
+ 1)
Micrel, Inc. 1849 Fortune Drive San Jose, CA 95131 USA tel + 1 (408) 944-0800 fax + 1 (408) 944-0970 http://www.micrel.com
LM4040/4041
Micrel
LM4040/4041
2
January 2000
Part Number *
Voltage
Accuracy,
Temp. Coefficient
LM4041AIM3-1.2
1.225V
0.1%, 100ppm/
C
LM4041BIM3-1.2
1.225V
0.2%, 100ppm/
C
LM4041CIM3-1.2
1.225V
0.5%, 100ppm/
C
LM4041DIM3-1.2
1.225V
1.0%, 150ppm/
C
LM4041CIM3-ADJ
1.24V to 10V
0.5%, 100ppm/
C
LM4041DIM3-ADJ
1.24V to 10V
1.0%, 150ppm/
C
Pin Configuration
1
2
3
FB
+
Adjustable Version
SOT-23 (M3) Package
Top View
Fixed Version
SOT-23 (M3) Package
Top View
1
2
3
+
Pin 3 must float or
be connected to pin 2.
Part Number *
Voltage
Accuracy,
Temp. Coefficient
LM4040AIM3-2.5
2.500V
0.1%, 100ppm/
C
LM4040BIM3-2.5
2.500V
0.2%, 100ppm/
C
LM4040CIM3-2.5
2.500V
0.5%, 100ppm/
C
LM4040DIM3-2.5
2.500V
1.0%, 150ppm/
C
LM4040AIM3-4.1
4.096V
0.1%, 100ppm/
C
LM4040BIM3-4.1
4.096V
0.2%, 100ppm/
C
LM4040CIM3-4.1
4.096V
0.5%, 100ppm/
C
LM4040DIM3-4.1
4.096V
1.0%, 150ppm/
C
LM4040AIM3-5.0
5.000V
0.1%, 100ppm/
C
LM4040BIM3-5.0
5.000V
0.2%, 100ppm/
C
LM4040CIM3-5.0
5.000V
0.5%, 100ppm/
C
LM4040DIM3-5.0
5.000V
1.0%, 150ppm/
C
Example
Field
Code
_ _ A
3rd Character
A =
0.1%
B =
0.2%
C =
0.5%
D =
1.0%
Example
Field
Code
_ 2 _
2nd Character 1 = 1.225V
2 = 2.500V
4 = 4.096V
5 = 5.000V
A = Adjustable
Example: R2C represents
Reference, 2.500V,
0.5% (LM4040CIM3-2.5)
Note: If 3rd character is omitted, container will
indicate tolerance.
SOT-23 Package Markings
Example
Field
Code
R _ _
1st Character
R = Reference
Ordering Information
January 2000
3
LM4040/4041
LM4040/4041
Micrel
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
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 .......................................... 60
A to 15mA
LM4040-4.1 .......................................... 68
A to 15mA
LM4040-5.0 .......................................... 74
A to 15mA
LM4041-1.2 .......................................... 60
A to 12mA
LM4041-ADJ ........................................ 60
A to 12mA
Output Voltage Range
LM4041-ADJ .......................................... 1.24V to 10V
+
Functional Diagram
LM4040, LM4041 Fixed
Functional Diagram
LM4041 Adjustable
+
FB
V
REF
LM4040/4041
Micrel
LM4040/4041
4
January 2000
LM4040-2.5 Electrical Characteristics
(Note 9)
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, B, C, and D designate initial Reverse
Breakdown Voltage tolerance of
0.1%,
0.2%,
0.5%, and
1.0 respectively.
LM4040AIM3 LM4040BIM3 LM4040CIM3
Symbol
Parameter
Conditions
Typical
Units
(Note 4)
Limits
Limits
Limits
(Limit)
(Note 5)
(Note 5)
(Note 5)
V
R
Reverse Breakdown Voltage
I
R
= 100
A
2.500
V
Reverse Breakdown Voltage
I
R
= 100
A
2.5
5.0
12
mV (max)
Tolerance
19
21
29
mV (max)
I
RMIN
Minimum Operating Current
45
A
60
60
60
A (max)
65
65
65
A (max)
V
R
/
T
Average Reverse Breakdown
I
R
= 10mA
20
ppm/
C
Voltage Temperature
I
R
= 1mA
15
100
100
100
ppm/
C (max)
Coefficient
I
R
= 100
A
15
ppm/
C (max)
V
R
/
I
R
Reverse Breakdown Voltage
I
RMIN
I
R
1mA
0.3
mV
Change with Operating
0.8
0.8
0.8
mV (max)
Current Change
1.0
1.0
1.0
mV (max)
1mA
I
R
15mA
2.5
mV
0.6
0.6
0.6
mV (max)
8.0
8.0
8.0
mV (max)
Z
R
Reverse Dynamic Impedance
I
R
= 1mA, f = 120Hz
0.3
I
AC
= 0.1 I
R
0.8
0.8
0.9
(max)
e
N
Wideband Noise
I
R
= 100
A
10Hz
f
10kHz
35
V
RMS
V
R
Reverse Breakdown Voltage
t = 1000hrs
Long Term Stability
T = 25
C
0.1
C
120
ppm
I
R
= 100
A
LM4040DIM3
Symbol
Parameter
Conditions
Typical
Units
(Note 4)
Limits
(Limit)
(Note 5)
V
R
Reverse Breakdown Voltage
I
R
= 100
A
2.500
V
Reverse Breakdown Voltage
I
R
= 100
A
25
mV (max)
Tolerance
49
mV (max)
I
RMIN
Minimum Operating Current
45
A
65
A (max)
70
A (max)
V
R
/
T
Average Reverse Breakdown
I
R
= 10mA
20
ppm/
C
Voltage Temperature
I
R
= 1mA
15
150
ppm/
C (max)
Coefficient
I
R
= 100
A
15
ppm/
C (max)
V
R
/
I
R
Reverse Breakdown Voltage
I
RMIN
I
R
1mA
0.3
mV
Change with Operating
1.0
mV (max)
Current Change
1.2
mV (max)
1mA
I
R
15mA
2.5
mV
8.0
mV (max)
10.0
mV (max)
Z
R
Reverse Dynamic Impedance
I
R
= 1mA, f = 120Hz
0.3
I
AC
= 0.1 I
R
1.1
(max)
e
N
Wideband Noise
I
R
= 100
A
10Hz
f
10kHz
35
V
RMS
V
R
Reverse Breakdown Voltage
t = 1000hrs
Long Term Stability
T = 25
C
0.1
C
120
ppm
I
R
= 100
A
January 2000
5
LM4040/4041
LM4040/4041
Micrel
LM4040-4.1 Electrical Characteristics
(Note 9)
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, B, C, and D designate initial Reverse
Breakdown Voltage tolerance of
0.1%,
0.2%,
0.5%, and
1.0% respectively.
LM4040AIM3
LM4040BIM3
Symbol
Parameter
Conditions
Typical
Units
(Note 4)
Limits
Limits
(Limit)
(Note 5)
(Note 5)
V
R
Reverse Breakdown Voltage
I
R
= 100
A
4.096
V
Reverse Breakdown Voltage
I
R
= 100
A
4.1
8.2
mV (max)
Tolerance
31
35
mV (max)
I
RMIN
Minimum Operating Current
50
A
68
68
A (max)
73
73
A (max)
V
R
/
T
Average Reverse Breakdown
I
R
= 10mA
30
ppm/
C
Voltage Temperature
I
R
= 1mA
20
100
100
ppm/
C (max)
Coefficient
I
R
= 100
A
20
ppm/
C (max)
V
R
/
I
R
Reverse Breakdown Voltage
I
RMIN
I
R
1mA
0.5
mV
Change with Operating
0.9
0.9
mV (max)
Current Change
1.2
1.2
mV (max)
1mA
I
R
15mA
3.5
mV
7.0
7.0
mV (max)
10.0
10.0
mV (max)
Z
R
Reverse Dynamic Impedance
I
R
= 1mA, f = 120Hz
0.5
I
AC
= 0.1 I
R
1.0
1.0
(max)
e
N
Wideband Noise
I
R
= 100
A
10Hz
f
10kHz
80
V
RMS
V
R
Reverse Breakdown Voltage
t = 1000hrs
Long Term Stability
T = 25
C
0.1
C
120
ppm
I
R
= 100
A
LM4040CIM3
LM4040DIM3
Symbol
Parameter
Conditions
Typical
Units
(Note 4)
Limits
Limits
(Limits)
(Note 5)
(Note 5)
V
R
Reverse Breakdown Voltage
I
R
= 100
A
4.096
V
Reverse Breakdown Voltage
I
R
= 100
A
20
41
mV (max)
Tolerance
47
81
mV (max)
I
RMIN
Minimum Operating Current
50
A
68
73
A (max)
73
78
A (max)
V
R
/
T
Average Reverse Breakdown
I
R
= 10mA
30
ppm/
C
Voltage Temperature
I
R
= 1mA
20
100
150
ppm/
C (max)
Coefficient
I
R
= 100
A
20
ppm/
C (max)
V
R
/
I
R
Reverse Breakdown Voltage
I
RMIN
I
R
1mA
0.5
mV
Change with Operating
0.9
1.2
mV (max)
Current Change
1.2
1.5
mV (max)
1mA
I
R
15mA
3.0
mV
7.0
9.0
mV (max)
10.0
13.0
mV (max)
Z
R
Reverse Dynamic Impedance
I
R
= 1mA, f = 120Hz
0.5
I
AC
= 0.1 I
R
1.0
1.3
(max)
e
N
Wideband Noise
I
R
= 100
A
10Hz
f
10kHz
80
V
RMS
V
R
Reverse Breakdown Voltage
t = 1000hrs
Long Term Stability
T = 25
C
0.1
C
120
ppm
I
R
= 100
A
LM4040/4041
Micrel
LM4040/4041
6
January 2000
LM4040-5.0 Electrical Characteristics
(Note 9)
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, B, C, and D designate initial Reverse
Breakdown Voltage tolerance of
0.1%,
0.2%,
0.5%, and
1.0% respectively.
LM4040AIM3
LM4040BIM3
Symbol
Parameter
Conditions
Typical
Units
(Note 4)
Limits
Limits
(Limit)
(Note 5)
(Note 5)
V
R
Reverse Breakdown Voltage
I
R
= 100
A
5.000
V
Reverse Breakdown Voltage
I
R
= 100
A
5.0
10
mV (max)
Tolerance
38
43
mV (max)
I
RMIN
Minimum Operating Current
54
A
74
74
A (max)
80
80
A (max)
V
R
/
T
Average Reverse Breakdown
I
R
= 10mA
30
ppm/
C
Voltage Temperature
I
R
= 1mA
20
100
100
ppm/
C (max)
Coefficient
I
R
= 100
A
20
ppm/
C (max)
V
R
/
I
R
Reverse Breakdown Voltage
I
RMIN
I
R
1mA
0.5
mV
Change with Operating
1.0
1.0
mV (max)
Current Change
1.4
1.4
mV (max)
1mA
I
R
15mA
3.5
mV
8.0
8.0
mV (max)
12.0
12.0
mV (max)
Z
R
Reverse Dynamic Impedance
I
R
= 1mA, f = 120Hz
0.5
I
AC
= 0.1 I
R
1.1
1.1
(max)
e
N
Wideband Noise
I
R
= 100
A
10Hz
f
10kHz
80
V
RMS
V
R
Reverse Breakdown Voltage
t = 1000hrs
Long Term Stability
T = 25
C
0.1
C
120
ppm
I
R
= 100
A
LM4040CIM3
LM4040DIM3
Symbol
Parameter
Conditions
Typical
Units
(Note 4)
Limits
Limits
(Limits)
(Note 5)
(Note 5)
V
R
Reverse Breakdown Voltage
I
R
= 100
A
5.000
V
Reverse Breakdown Voltage
I
R
= 100
A
25
50
mV (max)
Tolerance
58
99
mV (max)
I
RMIN
Minimum Operating Current
54
A
74
79
A (max)
80
85
A (max)
V
R
/
T
Average Reverse Breakdown
I
R
= 10mA
30
ppm/
C
Voltage Temperature
I
R
= 1mA
20
100
150
ppm/
C (max)
Coefficient
I
R
= 100
A
20
ppm/
C (max)
V
R
/
I
R
Reverse Breakdown Voltage
I
RMIN
I
R
1mA
0.5
mV
Change with Operating
1.0
1.3
mV (max)
Current Change
1.3
1.8
mV (max)
1mA
I
R
15mA
3.5
mV
8.0
10.0
mV (max)
12.0
15.0
mV (max)
Z
R
Reverse Dynamic Impedance
I
R
= 1mA, f = 120Hz
0.5
I
AC
= 0.1 I
R
1.1
1.5
(max)
e
N
Wideband Noise
I
R
= 100
A
10Hz
f
10kHz
80
V
RMS
V
R
Reverse Breakdown Voltage
t = 1000hrs
Long Term Stability
T = 25
C
0.1
C
120
ppm
I
R
= 100
A
January 2000
7
LM4040/4041
LM4040/4041
Micrel
LM4040 Typical Characteristics
+0.5
+0.4
+0.3
+0.2
+0.1
0
-0.1
-0.2
-0.3
-0.4
-0.5
-40
-22ppm/
C
-51ppm/
C
I
R
= 150A
12ppm/
C
TEMPERATURE (
C)
V
R
CHANGE (%)
Temperature Drift for Different
Average Temperature Coefficient
-20
0
20
40
60
80 100
Output Impedance
vs. Frequency
I
R
= I
RMIN
+ 100 A
V
R
= 5V
2.5V
100 1k 10k 100k 1M
FREQUENCY (Hz)
C
L
= 1F
TANTALUM
X
CL
1k
100
10
1
0.1
IMPEDANCE (
)
T
J
= 25
C,
I
R
= 0.1 I
R
C
L
= 0
Output Impedance
vs. Frequency
I
R
= 1mA
T
J
= 25
C,
I
R
= I
R
C
L
= 0
C
L
= 1F
TANTALUM
V
R
= 5V
2.5V
1k
100
10
1
0.1
100 1k 10k 100k 1M
FREQUENCY (Hz)
IMPEDANCE (
)
LM4040-5.0
R
S
= 30k
T
J
= 25
C
10
0
6
4
2
0
0 100 200 300 400
RESPONSE TIME (s)
V
R
(V)
V
IN
(V)
I
J
= 25
C
LM4040-2.5
R
S
= 30k
0 20 40 60 80
5
0
6
4
2
0
RESPONSE TIME (s)
V
R
(V)
V
IN
(V)
Test Circuit
V
IN
1Hz rate
LM4040
R
S
V
R
REVERSE VOLTAGE (V)
A, B, C, Suffix
D Suffix
Reverse Characteristics and
Minimum Operating Current
120
100
80
60
40
20
0
0 2 4 6 8 10
T
J
= 25
C
Typica
l
I RMIN
Guaranteed
2.5V
4.1V
5V
REVERSE CURRENT (A)
10.0
5.0
1 10 100 1k 10k 100k
FREQUENCY (Hz)
2.0
1.0
0.5
0.2
I
R
= 200A
T
J
= 25
C
5V
2.5V
Noise Voltage
vs. Frequency
0.1
Noise (V/ Hz )
LM4040/4041
Micrel
LM4040/4041
8
January 2000
LM4041-1.2 Electrical Characteristics
(Note 9)
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, B, C, and D designate initial Reverse
Breakdown Voltage tolerance of
0.1%,
0.2%,
0.5%, and
1.0%, respectively.
LM4041AIM3 LM4041BIM3 LM4041CIM3
Symbol
Parameter
Conditions
Typical
Units
(Note 4)
Limits
Limits
Limits
(Limit)
(Note 5)
(Note 5)
(Note 5)
V
R
Reverse Breakdown Voltage
I
R
= 100
A
1.225
V
Reverse Breakdown Voltage
I
R
= 100
A
1.2
2.4
6
mV (max)
Tolerance
9.2
10.4
14
mV (max)
I
RMIN
Minimum Operating Current
45
A
60
60
60
A (max)
65
65
65
A (max)
V
R
/
T
Average Reverse Breakdown
I
R
= 10mA
20
ppm/
C
Voltage Temperature
I
R
= 1mA
15
100
100
100
ppm/
C (max)
Coefficient
I
R
= 100
A
15
ppm/
C (max)
V
R
/
I
R
Reverse Breakdown Voltage
I
RMIN
I
R
1mA
0.7
mV
Change with Operating
1.5
1.5
1.5
mV (max)
Current Change
2.0
2.0
2.0
mV (max)
1mA
I
R
15mA
4.0
mV
6.0
6.0
6.0
mV (max)
8.0
8.0
8.0
mV (max)
Z
R
Reverse Dynamic Impedance
I
R
= 1mA, f = 120Hz
0.5
I
AC
= 0.1 I
R
1.5
1.5
1.5
(max)
e
N
Wideband Noise
I
R
= 100
A
10Hz
f
10kHz
20
V
RMS
V
R
Reverse Breakdown Voltage
t = 1000hrs
Long Term Stability
T = 25
C
0.1
C
120
ppm
I
R
= 100
A
LM4041DIM3
LM4041EIM3
Symbol
Parameter
Conditions
Typical
Units
(Note 4)
Limits
Limits
(Limit)
(Note 5)
(Note 5)
V
R
Reverse Breakdown Voltage
I
R
= 100
A
1.225
V
Reverse Breakdown Voltage
I
R
= 100
A
12
25
mV (max)
Tolerance
24
36
mV (max)
I
RMIN
Minimum Operating Current
45
A
65
65
A (max)
70
70
A (max)
V
R
/
T
Average Reverse Breakdown
I
R
= 10mA
20
ppm/
C
Voltage Temperature
I
R
= 1mA
15
150
150
ppm/
C (max)
Coefficient
I
R
= 100
A
15
ppm/
C (max)
V
R
/
I
R
Reverse Breakdown Voltage
I
RMIN
I
R
1mA
0.3
mV
Change with Operating
2.0
2.0
mV (max)
Current Change
2.5
2.5
mV (max)
1mA
I
R
15mA
2.5
mV
8.0
8.0
mV (max)
10.0
10.0
mV (max)
Z
R
Reverse Dynamic Impedance
I
R
= 1mA, f = 120Hz
0.3
I
AC
= 0.1 I
R
2.0
2.0
(max)
e
N
Wideband Noise
I
R
= 100
A
10Hz
f
10kHz
35
V
RMS
V
R
Reverse Breakdown Voltage
t = 1000hrs
Long Term Stability
T = 25
C
0.1
C
120
ppm
I
R
= 100
A
January 2000
9
LM4040/4041
LM4040/4041
Micrel
LM4041-Adjustable Electrical Characteristics
(Note 9)
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
< 12mA, V
REF
V
OUT
10V. The grades C and D designate initial Reverse Breakdown Voltage tolerance of
0.5% and
1%, respectively for V
OUT
= 5V.
LM4041CIM3
LM4041DIM3
Symbol
Parameter
Conditions
Typical
Units
(Note 4)
Limits
Limits
(Limit)
(Note 5)
(Note 5)
V
REF
Reference Breakdown Voltage
I
R
= 100
A
1.233
V
V
OUT
= 5V
Reference Breakdown Voltage
I
R
= 100
A
6.2
12
mV (max)
Tolerance (Note 8)
14
24
mV (max)
I
RMIN
Minimum Operating Current
45
A
60
65
A (max)
65
70
A (max)
V
REF
Reference Voltage
I
RMIN
I
R
1mA
0.7
mV
/
I
R
Change with Operating
SOT-23:
1.5
2.0
mV (max)
Current Change
V
OUT
1.6V
2.0
2.5
mV (max)
(Note 7)
1mA
I
R
15mA
2
mV
SOT-23:
4
6
mV (max)
V
OUT
1.6V
6
8
mV (max)
(Note 7)
V
REF
Reference Voltage Change
I
R
= 1mA
1.3
mV/V
/
V
O
with Output Voltage Change
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
Average Reference
V
OUT
= 5V
/
T
Voltage Temperature
I
R
= 10mA
20
ppm/
C
Coefficient
I
R
= 1mA
15
100
150
ppm/
C (max)
(Note 8)
I
R
= 100
A
15
ppm/
C (max)
Z
OUT
Dynamic Output Impedance
I
R
= 1mA, f = 120Hz
I
AC
= 0.1 I
R
V
OUT
= V
REF
0.3
V
OUT
= 10V
2
(max)
e
N
Wideband Noise
I
R
= 100
A
10Hz
f
10kHz
20
V
RMS
V
REF
Reference Voltage
t = 1000hrs
Long Term Stability
T = 25
C
0.1
C
120
ppm
I
R
= 100
A
LM4040/4041
Micrel
LM4040/4041
10
January 2000
+0.5
+0.4
+0.3
+0.2
+0.1
0
-0.1
-0.2
-0.3
-0.4
-0.5
-40
-22ppm/
C
-51ppm/
C
I
R
= 150A
LM4041-1.2
12ppm/
C
TEMPERATURE (
C)
V
R
CHANGE (%)
Temperature Drift for Different
Average Temperature Coefficient
-20
0
20
40
60
80 100
C
L
= 1F
TANTALUM
Output Impedence
vs. Frequency
1k
100
10
1
0.1
100 1k 10k 100k 1M
FREQUENCY (Hz)
T
J
= 25
C
I
R
= 0.1I
R
LM4041-1.2
C
L
= 0
X
C
I
R
= 150A
I
R
= 1mA
IMPEDANCE (
)
Voltage Impedance
1000
800
600
400
200
0
1 10 100 1k 10k 100k
FREQUENCY (Hz)
I
R
= 200A
TJ = 25
C
LM4041-1.2
LM4041-ADJ: V
OUT
= V
REF
NOISE (nV/ Hz )
Reverse Characteristics and
Minimum Operating Current
REVERSE VOLTAGE (V)
100
80
60
40
20
0
0 0.4 0.8 1.2 1.6 2.0
Typical
T
J
= 25
C
LM4041-1.2
REVERSE CURRENT (A)
Reverse Characteristics and
Minimum Operating Current
REVERSE VOLTAGE (V)
100
80
60
40
20
0
0 0.4 0.8 1.2 1.6 2.0
Typical
T
J
= 25
C
LM4041-1.2
REVERSE CURRENT (A)
R
S
30k
V
IN
1Hz rate
LM4041-1.2
V
R
Test Circuit
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 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.
Note 2.
The maximum power dissipation must be derated at elevated temperatures and is dictated by T
JMAX
(maximum junction temperature),
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
)/
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 (
JA
), when board mounted, is 326
C/W for the SOT-23 package.
Note 3.
The human body model is a 100pF capacitor discharged through a 1.5k
resistor into each pin. The machine model is a 200pF capacitor
discharged directly into each pin.
Note 4.
Typicals are at T
J
= 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 (SQL)
methods.
Note 6.
The boldface (over temperature limit for Reverse Breakdown Voltage Tolerance is defined as the room temperature Reverse Breakdown
Voltage Tolerance
[(
V
R
/
T)(65
C)(V
R
)].
V
R
/
T 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:
A-grade:
0.75% =
0.1%
100ppm/
C
65
C
B-grade:
0.85% =
0.2%
100ppm/
C
65
C
C-grade:
1.15% =
0.5%
100ppm/
C
65
C
D-grade:
1.98% =
1.0%
150ppm/
C
65
C
Example: The A-grade LM4040-2.5 has an over temperature Reverse Breakdown Voltage tolerance of
2.5
0.75% =
19mV.
Note 7.
When V
OUT
1.6V, the LM4041-ADJ must operate at reduced I
R
. This is caused by the series resistance of the die attach between the die ()
output and the package () output pin. See the Output Saturation 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.
Specification for packaged product only.
LM4040 and LM4041 Electrical Characteristic Notes
LM4041 Typical Characteristics
January 2000
11
LM4040/4041
LM4040/4041
Micrel
LM4041 Typical Characteristics
LM4041-ADJ
85
C
25
C
-40
C
-40
C
85
C
Reference Voltage vs. Output
Voltage and Temperature
1.244
1.240
1.236
1.232
1.228
1.224
1.220
0 2 4 6 8 10
OUTPUT VOLTAGE (V)
REFERENCE VOLTAGE (V)
Reference Voltage vs.
Temperature and Output Voltage
1.244
1.240
1.236
1.232
1.228
1.224
1.220
-40 -20 0 20 40 60 80 100
TEMPERATURE (
C)
LM4041-ADJ
V
OUT
= V
REF
V
OUT
= 5V
V
OUT
= 10V
I
R
= 1mA
REFERENCE VOLTAGE (V)
T
J
= 85
C
LM4041-ADJ
T
J
= 25
C, -40
C
Feedback Current vs.
Output Voltage and Temperature
0 2 4 6 8 10
OUTPUT VOLTAGE (V)
100
80
60
40
20
0
FEEDBACK (nA)
Output Saturation
0 2 4 6
8 10 12
OUTPUT CURRENT (mA)
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1.0
LM4041-ADJ
V
ADJ
= V
REF
+ 5V
-40
C
85
C
25
C
OUTPUT SATURATION (V)
LM4041-ADJ
T
J
= 25
C
I
R
= 1mA
I
R
= 0.1I
R
C
L
= 0
C
L
=1F
X
C
V
OUT
= 10V
5V
2.5V
1.23V
Output Impedence
vs. Frequency *
1K
100
10
1
0
100 1k 10k 100k 1M
FREQUENCY (Hz)
IMPEDANCE (
)
C
L
= 0
C
L
=1F
X
C
5V
2.5V
1.23V
FREQUENCY (Hz)
100 1k 10k 100k 1M
1K
100
10
1
0
Output Impedence
vs. Frequency *
IMPEDANCE (
)
V
OUT
= 10V
LM4041-ADJ
T
J
= 25
C
I
R
= 1mA
I
R
= 0.1 I
R
FB STEPS (V)
0 2 4 6 8 10
T
J
= 25
C
LM4041-ADJ
0 2 4 6 8
100
80
60
40
20
0
Reverse Characteristics
OUTPUT VOLTAGE (V)
REVERSE CURRENT (A)
LM4041-ADJ
T
J
= -40
C
25
C
85
C
0 10 20 30 40
-40
C
OUTPUT
INPUT
-40
C
Large Signal Response
10
8
6
4
2
0
RESPONSE TIME (s)
VOLTAGE (V)
* Output Impedance vs. Freq.
Test Circuit
Large Signal Response
Test Circuit
Reverse Characteristics
Test Circuit
FB
2V / step
V
OUT
I
R
( + )
( )
LM4041-ADJ
V
VOUT
LM4041 - ADJ
( + )
FB
( - )
100k
INPUT
+ 15V
5.1k
+
C
L
120k
FB
I
R
LM4040/4041
Micrel
LM4040/4041
12
January 2000
Applications Information
The LM4040 and LM4041 have been designed for stable
operation without the need of an external capacitor con-
nected between the (+) and () pins. If a bypass capacitor is
used, the references remain stable.
Schottky Diode
LM4040-x.x and LM4041-1.2 in the SOT-23 package have a
parasitic Schottky diode between pin 2 () and pin 3 (die
attach interface connect). Pin 3 of the SOT-23 package must
float or be connected to pin 2. LM4041-ADJs use pin 3 as the
() output.
Conventional Shunt Regulator
In a conventional shunt regulator application (see Figure 1),
an external series resistor (R
S
) is connected between the
supply voltage and the LM4040-x.x or LM4041-1.2 reference.
R
S
determines the current that flows through the load (I
L
) and
the reference (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 reference 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 LM4040-x.x is less than
15mA, and the current flowing through the LM4041-1.2 or
LM4041-ADJ is less than 12mA.
R
S
is determined by the supply voltage (V
S
), the load and
operating current, (I
L
and I
Q
), and the reference's reverse
breakdown voltage (V
R
).
R
s
= (V
s
V
R
) / (I
L
+ I
Q
)
Adjustable Regulator
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 is found
using the equation
(1)
V
O
= V
REF
[ (R2/R1) + 1 ]
where V
O
is the desired output voltage. The actual value of
the internal V
REF
is a function of V
O
. The "corrected" V
REF
is
determined by
(2)
V
REF
= V
O
(
V
REF
/
V
O
) + V
Y
where V
O
is the desired output voltage.
V
REF
/
V
O
is found
in the Electrical Characteristics and is typically 1.3mV/V and
V
Y
is equal to 1.233V. Replace the value of V
REF
in equation
(1) with the value found using equation (2).
Note that actual output voltage can deviate from that pre-
dicted using the typical
V
REF
/
V
O
in equation (2); for C-
grade parts, the worst-case
V
REF
/
V
O
is 2.5mV/V and
V
Y
= 1.248V.
The following example shows the difference in output voltage
resulting from the typical and worst case values of
V
REF
/
V
O
:
Let V
O
= +9V. Using the typical values of
V
REF
/
V
O
, V
REF
is 1.223V. Choosing a value of R1 = 10k
, R2 = 63.272k
.
Using the worst case
V
REF
/
V
O
for the C-grade and D-
grade parts, the output voltage is actually 8.965V and 8.946V
respectively. This results in possible errors as large as 0.39%
for the C-grade parts and 0.59% for the D-grade parts. Once
again, resistor values found using the typical value of
V
REF
/
V
O
will work in most cases, requiring no further
adjustment.
Figure 4. Voltage Level Detector
R1
120k
R2
1M
FB
+
LM4041-ADJ
D1
< 12V
LED ON
R3
200
5V
D1
LM4041-
ADJ
R1
120k
R2
1M
FB
+
R3
330
> 12V
LED ON
5V
Figure 3. Voltage Level Detector
January 2000
13
LM4040/4041
LM4040/4041
Micrel
Figure 8. Bidirectional Adjustable Clamp
2.4 to
6V
V
IN
R1
I
LM4041-ADJ
D2
1N457
R3
1M
R2
330k
V
OUT
LM4041-ADJ
FB
+
FB
+
D1
1N457
R4
330k
V
IN
R1
R2
390k
R3
500k
FB
+
LM4041-ADJ
D1
1N457
R4
390k
D2
1N457
LM4041-ADJ
FB
+
I
V
OUT
Figure 7. Bidirectional Adjustable Clamp
18V to
2.4V
0 to 20mA
R1
390
2%
1N4002
D2
LM4041-ADJ
+
FB
D1*
1
2
3
6
5
4
4N28
N.C.
I
THRESHOLD
=
+
= 3.2mA
1.24V
R1
5A
4N28 GAIN
N.C.
R2
470k
CMOS
+ 5V
Figure 9. Floating Current Detector
D1
1N457
R3
510k
LM4041-ADJ
D2
1N457
V
OUT
R2
510k
V
IN
R1
I
+
FB
FB
LM4041-ADJ
+
Figure 6. Bidirectional Clamp
2.4V
Figure 5. Fast Positive Clamp
2.4V +
V
D1
V
IN
V
OUT
D1
1N914
D2
1N914
R3
240k
R4
240k
R1
I
R2
50A
LM4041-ADJ
FB
+
LM4040/4041
Micrel
LM4040/4041
14
January 2000
+15V
R1
2N2905
2N
3964
R2
120k
LM4041-ADJ
FB
+
1.24V
R1
I
OUT
=
1A < I
OUT
= 100mA
+5V
R3
100k
CMOS
R4
10M
1
2
3
6
5
4
4N28
N.C.
R2
22k
LM4041-ADJ
+
R1
332
1%
FB
1N914
2N2222
D1*
I
THRESHOLD
=
= 3.7mA
2%
1.24V
R1
D2
1N4002
0 to 20 mA
Figure 10. Current Source
Figure 11. Precision Floating Current Detector
* D1 can be any LED, V
F
= 1.5V to 2.2V at 3mA. D1 may act as an indicator. D1 will
be on if I
THRESHOLD
falls below the threshold current, except with I = O.
January 2000
15
LM4040/4041
LM4040/4041
Micrel
Package Information
0.15 (0.006)
0.076 (0.0030)
0.41 (0.016)
0.13 (0.005)
3.05 (0.120)
2.67 (0.105)
8
0
0.445 (0.0175) TYP 3 PLACES
2.50 (0.098)
2.10 (0.083)
1.40 (0.055)
1.19 (0.047)
0.10 (0.004)
0.013 (0.0005)
1.15 (0.045)
0.76 (0.030)
DIMENSIONS:
MM (INCH)
2.36 (0.093)
2.28 (0.090)
C
L
C
L
SOT-23 (M3)
LM4040/4041
Micrel
LM4040/4041
16
January 2000
MICREL INC.
1849 FORTUNE DRIVE
SAN JOSE, CA 95131
USA
TEL
+ 1 (408) 944-0800
FAX
+ 1 (408) 944-0970
WEB
http://www.micrel.com
This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or
other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc.
2000 Micrel Incorporated
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