Micrel LM4040DIM3-2.5 Precision micropower shunt voltage reference Datasheet

LM4040/4041
Micrel, Inc.
LM4040/4041
Precision Micropower Shunt Voltage Reference
General Description
Features
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 available 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 versions have a maximum operating current of 12mA.
The LM4040 and LM4041 have bandgap reference temperature 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.
•
•
•
•
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 ................................................. 35µVRMS (typ)
LM4041 ................................................. 20µVRMS (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
VS
VS
RS
VR
LM4040
LM4041
RS
I Q + IL
IL
VO
VO
LM4041
Adjustable
IQ
Figure 1. LM4040, LM4041 Fixed
Shunt Regulator Application
R1
VO = 1.233 (R2/R1 + 1)
R2
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
1
3–
3
+
2
Pin 3 must float or be
connected to pin 2.
Adjustable Version
SOT-23 (M3) Package
Fixed Version
SOT-23 (M3) Package
Ordering Information
Standard
Part Number
Pb-Free
Voltage
Accuracy,
Temp. Coefficient
LM4040CIM3-2.5
LM4040CYM3-2.5
2.500V
±0.5%, 100ppm/°C
LM4040DIM3-2.5
LM4040DYM3-2.5
2.500V
±1.0%, 150ppm/°C
LM4040CIM3-4.1
LM4040CYM3-4.1
4.096V
±0.5%, 100ppm/°C
LM4040DIM3-4.1
LM4040DYM3-4.1
4.096V
±1.0%, 150ppm/°C
LM4040CIM3-5.0
LM4040CYM3-5.0
5.000V
±0.5%, 100ppm/°C
LM4040DIM3-5.0
LM4040DYM3-5.0
5.000V
±1.0%, 150ppm/°C
LM4041CIM3-1.2
LM4041CYM3-1.2
1.225V
±0.5%, 100ppm/°C
LM4041DIM3-1.2
LM4041DYM3-1.2
1.225V
±1.0%, 150ppm/°C
LM4041CIM3-ADJ
LM4041CYM3-ADJ
1.24V to 10V
±0.5%, 100ppm/°C
LM4041DIM3-ADJ
LM4041DYM3-ADJ
1.24V to 10V
±1.0%, 150ppm/°C
SOT-23 Package Markings
Example
Field
Code
R__
1st Character
R = Reference
Y__
1st Character
Y = Pb-Free
Example: R2C represents Reference, 2.500V,
±0.5% (LM4040CIM3-2.5)
Example
_2_
Field
Example: Y1C represents Pb-Free, 1.225V,
±0.5% (LM4040CYM3-1.2)
M9999-031805
Code
2nd Character 1 = 1.225V
2 = 2.500V
4 = 4.096V
5 = 5.000V
A = Adjustable
2
Example
__C
Field
Code
3rd Character C = ±0.5%
D = ±1.0%
X = ±0.5% Pb-Free
Y = ±1.0% Pb-Free
Note: If 3rd character is omitted, container will
indicate tolerance.
March 2005
LM4040/4041
Micrel, Inc.
+
+
VREF
FB
Functional Diagram
LM4040, LM4041 Fixed
Functional Diagram
LM4041 Adjustable
Absolute Maximum Ratings
Operating Ratings (Notes 1 and 2)
Reverse Current ......................................................... 20mA
Forward Current ......................................................... 10mA
Maximum Output Voltage
LM4041-Adjustable.................................................... 15V
Power Dissipation at TA = 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
Temperature Range
(TMIN ≤ TA ≤ TMAX) ............................–40°C ≤ TA ≤ +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
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 TJMAX (maximum junction temperature), θJA
(junction to ambient thermal resistance), and TA (ambient temperature). The maximum allowable power dissipation at any temperature is PDMAX = (TJMAX – TA)/θJA or the number given in the Absolute Maximum Ratings, whichever is lower. For the LM4040 and LM4041,
TJMAX = 125°C, and the typical thermal resistance (θJA), 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 1.5kΩ resistor into each pin. The machine model is a 200pF capacitor
discharged directly into each pin.
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LM4040/4041
Micrel, Inc.
LM4040-2.5 Electrical Characteristics (Note 4)
Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = 25°C. The grades C and D designate initial Reverse Breakdown Voltage tolerance of ±0.5% and ±1.0 respectively.
Symbol
Parameter
Conditions
(Note 5)
Typical
Limits
VR
Reverse Breakdown Voltage
IR = 100µA
2.500
Reverse Breakdown Voltage
Tolerance (Note 7)
IRMIN
Minimum Operating Current
ΔVR/ΔT
Average Reverse Breakdown
Voltage Temperature
Coefficient
ΔVR/ΔIR
Reverse Breakdown Voltage
Change with Operating
Current Change
IR = 100µA
45
IR = 10mA
IR = 1mA
IR = 100µA
±20
±15
±15
IRMIN ≤ IR 1mA
0.3
1mA ≤ IR 15mA
2.5
IR = 1mA, f = 120Hz
IAC = 0.1 IR
0.3
ZR
Reverse Dynamic Impedance
eN
Wideband Noise
IR = 100µA
10Hz ≤ f ≤ 10kHz
ΔVR
Reverse Breakdown Voltage
Long Term Stability
t = 1000hrs
T = 25°C ±0.1°C
IR = 100µA
Limits
(Limit)
(Note 6)
Units
V
±12
±29
±25
±49
mV (max)
mV (max)
60
65
65
70
µA
µA (max)
µA (max)
±100
±150
0.8
1.0
1.0
1.2
mV
mV (max)
mV (max)
6.0
8.0
8.0
10.0
mV
mV (max)
mV (max)
0.9
1.1
Ω
Ω (max)
ppm/°C
ppm/°C (max)
ppm/°C (max)
µVRMS
120
ppm
Specification for packaged product only.
Note 5.
Typicals are at TJ = 25°C and represent most likely parametric norm.
Note 7.
(Note 6)
LM4040DIM3
35
Note 4.
Note 6.
LM4040CIM3
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 Voltage Tolerance ±[(ΔVR/ΔT)(65°C)(VR)]. ΔVR/ΔT is the VR temperature coefficient, 65°C is the temperature range from –40°C to the reference
point of 25°C, and VR 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.
LM4040-4.1 Electrical Characteristics (Note 4)
Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = 25°C. The grades C and D designate initial Reverse Breakdown Voltage tolerance of ±0.5% and ± 1.0% respectively.
Symbol
VR
Parameter
Reverse Breakdown Voltage
Reverse Breakdown Voltage
Tolerance (Note 7)
IRMIN
Minimum Operating Current
ΔVR/ΔT
Average Reverse Breakdown
Voltage Temperature
Coefficient
ΔVR/ΔIR
Reverse Breakdown Voltage
Change with Operating
Current Change
Conditions
Typical
(Note 5)
(Note 6)
IR = 100µA
4.096
IR = 100µA
50
IR = 10mA
IR = 1mA
IR = 100µA
±30
±20
±20
IRMIN ≤ IR 1mA
0.5
1mA ≤ IR 15mA
3.0
IR = 1mA, f = 120Hz
IAC = 0.1 IR
0.5
ZR
Reverse Dynamic Impedance
eN
Wideband Noise
IR = 100µA
10Hz ≤ f ≤ 10kHz
ΔVR
Reverse Breakdown Voltage
Long Term Stability
t = 1000hrs
T = 25°C ±0.1°C
IR = 100µA
Limits
(Note 6)
Limits
Units
(Limits)
±20
±47
±41
±81
mV (max)
mV (max)
68
73
73
78
µA
µA (max)
µA (max)
±100
±150
0.9
1.2
1.2
1.5
mV
mV (max)
mV (max)
7.0
10.0
9.0
13.0
mV
mV (max)
mV (max)
1.0
1.3
Ω
Ω (max)
V
ppm/°C
ppm/°C (max)
ppm/°C (max)
µVRMS
120
ppm
Specification for packaged product only.
Note 5.
Typicals are at TJ = 25°C and represent most likely parametric norm.
Note 7.
LM4040DIM3
80
Note 4.
Note 6.
LM4040CIM3
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 Voltage Tolerance ±[(ΔVR/ΔT)(65°C)(VR)]. ΔVR/ΔT is the VR temperature coefficient, 65°C is the temperature range from –40°C to the reference
point of 25°C, and VR 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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M9999-031805
LM4040/4041
Micrel, Inc.
LM4040-5.0 Electrical Characteristics (Note 4)
Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = 25°C. The grades C and D designate initial Reverse Breakdown Voltage tolerance of ±0.5% and ± 1.0% respectively.
Symbol
VR
Parameter
Reverse Breakdown Voltage
Reverse Breakdown Voltage
Tolerance (Note 7)
IRMIN
Minimum Operating Current
ΔVR/ΔT
Average Reverse Breakdown
Voltage Temperature
Coefficient
ΔVR/ΔIR
Reverse Breakdown Voltage
Change with Operating
Current Change
Conditions
Typical
(Note 5)
(Note 6)
IR = 100µA
5.000
IR = 100µA
54
IR = 10mA
IR = 1mA
IR = 100µA
±30
±20
±20
IRMIN ≤ IR 1mA
0.5
1mA ≤ IR 15mA
3.5
IR = 1mA, f = 120Hz
IAC = 0.1 IR
0.5
ZR
Reverse Dynamic Impedance
eN
Wideband Noise
IR = 100µA
10Hz ≤ f ≤ 10kHz
ΔVR
Reverse Breakdown Voltage
Long Term Stability
t = 1000hrs
T = 25°C ±0.1°C
IR = 100µA
Limits
(Note 6)
Limits
Units
(Limits)
±25
±58
±50
±99
mV (max)
mV (max)
74
80
79
85
µA
µA (max)
µA (max)
±100
±150
1.0
1.4
1.3
1.8
mV
mV (max)
mV (max)
8.0
12.0
10.0
15.0
mV
mV (max)
mV (max)
1.1
1.5
Ω
Ω (max)
V
ppm/°C
ppm/°C (max)
ppm/°C (max)
µVRMS
120
ppm
Specification for packaged product only.
Note 5.
Typicals are at TJ = 25°C and represent most likely parametric norm.
Note 7.
LM4040DIM3
80
Note 4.
Note 6.
LM4040CIM3
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 Voltage Tolerance ±[(ΔVR/ΔT)(65°C)(VR)]. ΔVR/ΔT is the VR temperature coefficient, 65°C is the temperature range from –40°C to the reference
point of 25°C, and VR 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.
LM4040 Typical Characteristics
RS
VIN
1Hz rate
LM4040
VR
Test Circuit
March 2005
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M9999-031805
LM4040/4041
Micrel, Inc.
LM4041-1.2 Electrical Characteristics (Note 4)
Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = 25°C. The grades C and D designate initial Reverse Breakdown Voltage tolerance of ±0.5% and ± 1.0%, respectively.
Symbol
Parameter
Conditions
(Note 5)
Typical
VR
Reverse Breakdown Voltage
IR = 100µA
1.225
Reverse Breakdown Voltage
Tolerance (Note 7)
IRMIN
Minimum Operating Current
ΔVR/ΔT
Average Reverse Breakdown
Voltage Temperature
Coefficient
ΔVR/ΔIR
Reverse Breakdown Voltage
Change with Operating
Current Change
IR = 100µA
45
IR = 10mA
IR = 1mA
IR = 100µA
±20
±15
±15
IRMIN ≤ IR 1mA
0.7
1mA ≤ IR 15mA
4.0
IR = 1mA, f = 120Hz
IAC = 0.1 IR
0.5
ZR
Reverse Dynamic Impedance
eN
Wideband Noise
IR = 100µA
10Hz ≤ f ≤ 10kHz
ΔVR
Reverse Breakdown Voltage
Long Term Stability
t = 1000hrs
T = 25°C ±0.1°C
IR = 100µA
(Note 6)
(Limit)
Units
V
±6
±14
mV (max)
mV (max)
60
65
µA
µA (max)
µA (max)
±100
ppm/°C
ppm/°C (max)
ppm/°C (max)
1.5
2.0
mV
mV (max)
mV (max)
6.0
8.0
mV
mV (max)
mV (max)
1.5
Ω
Ω (max)
µVRMS
120
ppm
Specification for packaged product only.
Note 5.
Typicals are at TJ = 25°C and represent most likely parametric norm.
Note 7.
Limits
20
Note 4.
Note 6.
LM4041CIM3
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 Voltage Tolerance ±[(ΔVR/ΔT)(65°C)(VR)]. ΔVR/ΔT is the VR temperature coefficient, 65°C is the temperature range from –40°C to the reference
point of 25°C, and VR 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
8
March 2005
LM4040/4041
Micrel, Inc.
LM4041-1.2 Electrical Characteristics (Note 4)
Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = 25°C. The grades C and D designate initial Reverse Breakdown Voltage tolerance of ±0.5% and ± 1.0%, respectively.
Symbol
VR
Parameter
Reverse Breakdown Voltage
Reverse Breakdown Voltage
Tolerance (Note 7)
IRMIN
Minimum Operating Current
ΔVR/ΔT
Average Reverse Breakdown
Voltage Temperature
Coefficient
ΔVR/ΔIR
Reverse Breakdown Voltage
Change with Operating
Current Change
Conditions
Typical
(Note 5)
IR = 100µA
1.225
IR = 100µA
45
IR = 10mA
IR = 1mA
IR = 100µA
±20
±15
±15
IRMIN ≤ IR 1mA
0.7
1mA ≤ IR 15mA
2.5
IR = 1mA, f = 120Hz
IAC = 0.1 IR
0.5
ZR
Reverse Dynamic Impedance
eN
Wideband Noise
IR = 100µA
10Hz ≤ f ≤ 10kHz
ΔVR
Reverse Breakdown Voltage
Long Term Stability
t = 1000hrs
T = 25°C ±0.1°C
IR = 100µA
Note 4.
Specification for packaged product only.
Note 5.
Typicals are at TJ = 25°C and represent most likely parametric norm.
Note 6.
Note 7.
LM4041DIM3
Limits
(Note 6)
Units
(Limit)
±12
±24
mV (max)
mV (max)
65
70
µA
µA (max)
µA (max)
V
±150
ppm/°C
ppm/°C (max)
ppm/°C (max)
2.0
2.5
mV
mV (max)
mV (max)
8.0
10.0
mV
mV (max)
mV (max)
2.0
Ω
Ω (max)
20
µVRMS
120
ppm
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 Voltage Tolerance ±[(ΔVR/ΔT)(65°C)(VR)]. ΔVR/ΔT is the VR temperature coefficient, 65°C is the temperature range from –40°C to the reference
point of 25°C, and VR 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
9
M9999-031805
LM4040/4041
Micrel, Inc.
LM4041-Adjustable Electrical Characteristics (Note 4)
Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TJ = 25°C unless otherwise specified (SOT-23, see Note 8),
IRMIN ≤ IR < 12mA, VREF ≤ VOUT ≤ 10V. The grades C and D designate initial Reverse Breakdown Voltage tolerance of ±0.5% and ±1%,
respectively for VOUT = 5V.
Symbol
Parameter
Conditions
(Note 5)
Typical
Limits
VREF
Reference Breakdown Voltage
IR = 100µA
VOUT = 5V
1.233
Reference Breakdown Voltage
Tolerance (Note 9)
IRMIN
Minimum Operating Current
ΔVREF
/ΔIR
Reference Voltage
Change with Operating
Current Change
ΔVREF
/ΔVO
Reference Voltage Change
with Output Voltage Change
IFB
Feedback Current
ΔVREF
/ΔT
Average Reference
Voltage Temperature
Coefficient
(Note 9)
ZOUT
Dynamic Output Impedance
eN
Wideband Noise
ΔVREF
Reference Voltage
Long Term Stability
IR = 100µA
45
IRMIN ≤ IR 1mA
SOT-23:
VOUT ≥ 1.6V
(Note 8)
0.7
1mA ≤ IR 15mA
SOT-23:
VOUT ≥ 1.6V
(Note 8)
2
IR = 1mA
–1.55
60
VOUT = 5V
IR = 10mA
IR = 1mA
IR = 100µA
IR = 1mA, f = 120Hz
IAC = 0.1 IR
VOUT = VREF
VOUT = 10V
±20
±15
±15
(Limit)
(Note 6)
Units
V
±6.2
±14
±12
±24
mV (max)
mV (max)
60
65
65
70
µA
µA (max)
µA (max)
1.5
2.0
2.0
2.5
mV
mV (max)
mV (max)
4
6
6
8
mV
mV (max)
mV (max)
–2.0
–2.5
–2.5
–3.0
mV/V
mV/V (max)
mV/V (max)
100
120
150
200
nA
nA (max)
nA (max)
±100
±150
ppm/°C
ppm/°C (max)
ppm/°C (max)
20
µVRMS
120
ppm
Specification for packaged product only.
Note 5.
Typicals are at TJ = 25°C and represent most likely parametric norm.
Note 7.
Limits
(Note 6)
Ω
Ω (max)
Note 4.
Note 6.
LM4041DIM3
0.3
2
IR = 100µA
10Hz ≤ f ≤ 10kHz
t = 1000hrs
T = 25°C ±0.1°C
IR = 100µA
LM4041CIM3
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 Voltage Tolerance ±[(ΔVR/ΔT)(65°C)(VR)]. ΔVR/ΔT is the VR temperature coefficient, 65°C is the temperature range from –40°C to the reference
point of 25°C, and VR 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.
Note 8.
When VOUT ≤ 1.6V, the LM4041-ADJ 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 curve in the “Typical Performance Characteristics” section.
Note 9.
Reference voltage and temperature coefficient will change with output voltage. See “Typical Performance Characteristics” curves.
M9999-031805
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March 2005
LM4040/4041
Micrel, Inc.
LM4041 Typical Characteristics
RS 30k
VIN
1Hz rate
V
R
LM4041-1.2
Test Circuit
March 2005
11
M9999-031805
LM4040/4041
Micrel, Inc.
LM4041 Typical Characteristics
IR
(+)
LM4041-ADJ
FB
V OUT
( – ) 2V / step
V
†
Reverse Characteristics
Test Circuit
IR
+
CL
120k
FB
–
* Output Impedance vs. Freq.
Test Circuit
+ 15V
5.1k
INPUT
FB
100k
‡
M9999-031805
(+)
LM4041-ADJ
VOUT
(–)
* Output impedance measurement..
†
Reverse characteristics measurement.
‡
Large signal response measurement.
Large Signal Response
Test Circuit
12
March 2005
LM4040/4041
Micrel, Inc.
Applications Information
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 (VREF) and the ratio of the external feedback resistors as shown in Figure 2. The output
is found using the equation:
(1)
VO = VREF [ (R2/R1) + 1 ]
where VO is the desired output voltage. The actual value of
the internal VREF is a function of VO. The “corrected” VREF
is determined by:
(2)
VREF´ = VO (ΔVREF / ΔVO) + VY
where VO is the desired output voltage. ΔVREF / ΔVO is found
in the “Electrical Characteristics” and is typically –1.3mV/V and
VY is equal to 1.233V. Replace the value of VREF in equation
(1) with the value VREF found using equation (2).
Note that actual output voltage can deviate from that predicted using the typical ΔVREF / ΔVO in equation (2); for Cgrade parts, the worst-case ΔVREF / ΔVO is –2.5mV/V and
VY = 1.248V.
The following example shows the difference in output voltage resulting from the typical and worst case values of
ΔVREF / ΔVO.
Let VO = +9V. Using the typical values of ΔVREF /ΔVO , VREF
is 1.223V. Choosing a value of R1 = 10kΩ, R2 = 63.272kΩ.
Using the worst case ΔVREF / ΔVO for the C-grade and Dgrade 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
ΔVREF / ΔVO will work in most cases, requiring no further
adjustment.
The stable operation of the LM4040 and LM4041 references
requires an external capacitor greater than 10nF connected
between the (+) and (–) pins. Bypass capacitors with values
between 100pF and 10nF have been found to cause the
devices to exhibit instabilities.
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 (RS) is connected between the
supply voltage and the LM4040-x.x or LM4041-1.2 reference.
RS determines the current that flows through the load (IL)
and the reference (IQ). Since load current and supply voltage may vary, RS should be small enough to supply at least
the minimum acceptable IQ 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 IL is at its minimum, RS 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.
RS is determined by the supply voltage (VS), the load and
operating current, (IL and IQ), and the reference’s reverse
breakdown voltage (VR):
Rs = (Vs – VR) / (IL + IQ)
Typical Application Circuits
R1
+ FB 120k
LM4041-ADJ
D1
–
λ
D1
R2
1M
FB
LM4041–
ADJ
λ
R1
120k
R2
1M
> –12V
R3
LED ON
330
< –12V
R3
LED ON
200
–5V
–5V
Figure 3. Voltage Level Detector
March 2005
+
Figure 4. Voltage Level Detector
13
M9999-031805
LM4040/4041
Micrel, Inc.
VIN
R1
I
VOUT
D1
1N914
R2
50A
VIN
I
D2
1N914
+
LM4041-ADJ
FB
–
R3
240k
+
LM4041-ADJ
R4
240k
Figure 5. Fast Positive Clamp
2.4V + ∆VD1
FB
–
D1
1N457
+
LM4041-ADJ
VIN
R1
R2
390k
R3
500k
I
FB –
D1
1N457
R1
VOUT
VOUT
D2
1N457
+
LM4041-ADJ
LM4041-ADJ
+
FB
–
FB
–
VOUT
R2
D2
510k – 1N457
FB
LM4041-ADJ
+
R3
510k
Figure 6. Bidirectional Clamp
±2.4V
VIN
I
R1
R4
390k
D1
1N457
Figure 7. Bidirectional Adjustable Clamp
±18V to ±2.4V
R2
330k
R3
1M
D2
1N457
FB –
R4
330k
LM4041-ADJ
+
Figure 8. Bidirectional Adjustable Clamp
±2.4 to ±6V
0 to 20mA
1N4002
D2
+ 5V
R1
390Ω
± 2%
D1*
+
FB
LM4041-ADJ
–
λ
N.C.
I THRESHOLD =
1
6
2
5
3
4N28
N.C.
R2
470k
CMOS
4
1.24V
5A
+
= 3.2mA
R1 4N28 GAIN
* D1 can be any LED, VF = 1.5V to 2.2V at 3mA. D1 may act as an indicator.
D1 will be on if ITHRESHOLD falls below the threshold current, except with I = O.
Figure 9. Floating Current Detector
M9999-031805
14
March 2005
LM4040/4041
Micrel, Inc.
+15V
+
LM4041-ADJ
R1
FB
–
2N2905
2N
3964
R2
120k
1A < IOUT = 100mA
1.24V
I OUT =
R1
Figure 10. Current Source
0 to 20 mA
R1
332Ω
±1%
D2
1N4002
+5V
+
FB
1N914
LM4041-ADJ
–
R3
100k
2N2222
R2
22k
D1*
λ
1
6
2
5
3
N.C.
1.24V
I THRESHOLD =
= 3.7mA ± 2%
R1
4N28
4
R4
10M
CMOS
* D1 can be any LED, VF = 1.5V to 2.2V at 3mA. D1 may act as an indicator.
D1 will be on if ITHRESHOLD falls below the threshold current, except with I = O.
Figure 11. Precision Floating Current Detector
March 2005
15
M9999-031805
LM4040/4041
Micrel, Inc.
Package Information
SOT-23 (M3)
MICREL INC.
2180 FORTUNE DRIVE
SAN JOSE, CA 95131
USA
TEL + 1 (408) 944-0800 FAX + 1 (408) 474-1000 WEB http://www.micrel.com
This information furnished by Micrel in this data sheet is believed to be accurate and reliable. However no responsibility is assumed by Micrel for its use.
Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can
reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into
the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser's
use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser's own risk and Purchaser agrees to fully indemnify
Micrel for any damages resulting from such use or sale.
© 2004 Micrel Incorporated
M9999-031805
16
March 2005
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