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March 2005 1 M9999-031805
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
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. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
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LM4040
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LM4041
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