LM4040/LM4041

LM4040/LM4041
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 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.
Datasheets and support documentation are available 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.
Applications








Battery-powered equipment
Data acquisition systems
Instrumentation
Process control
Energy management
Product testing
Automotive electronics
Precision audio components
Typical Application
LM4040, LM4041 Fixed Shunt
Regulator Application
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
June 24, 2014
Revision 3.0
Micrel, Inc.
LM4040/LM4041
Ordering Information
Part Number
Marking
Voltage
Accuracy, Temp. Coefficient
Package
LM4040CYM3-2.5
Y2C
2.500V
±0.5%, 100ppm/°C
3-Pin SOT-23
LM4040DYM3-2.5
Y2D
2.500V
±1.0%, 150ppm/°C
3-Pin SOT-23
LM4040CYM3-4.1
Y4C
4.096V
±0.5%, 100ppm/°C
3-Pin SOT-23
LM4040DYM3-4.1
Y4D
4.096V
±1.0%, 150ppm/°C
3-Pin SOT-23
LM4040CYM3-5.0
Y5C
5.000V
±0.5%, 100ppm/°C
3-Pin SOT-23
LM4040DYM3-5.0
Y5D
5.000V
±1.0%, 150ppm/°C
3-Pin SOT-23
LM4041CYM3-1.2
Y1C
1.225V
±0.5%, 100ppm/°C
3-Pin SOT-23
LM4041DYM3-1.2
Y1D
1.225V
±1.0%, 150ppm/°C
3-Pin SOT-23
LM4041CYM3-ADJ
YAC
1.24V to 10V
±0.5%, 100ppm/°C
3-Pin SOT-23
LM4041DYM3-ADJ
YAD
1.24V to 10V
±1.0%, 150ppm/°C
3-Pin SOT-23
Pin Configuration
SOT-23 (M3)
Fixed Version
SOT-23 (M3)
Adjustable Version
Pin Description
Pin Number
Fixed
Pin Number
Adjustable
Pin Name
1
2
+
-
1
FB
2
3
-
3
-
NC
June 24, 2014
Pin Function
Cathode, connect to positive voltage.
Feedback, connect to a resistive divider network to set the output voltage.
Anode, connect to negative voltage.
Not internally connected. This pin must be left floating or connected to – (Pin 2).
2
Revision 3.0
Micrel, Inc.
LM4040/LM4041
Absolute Maximum Ratings(1)
Operating Ratings(2)
Reverse Current .......................................................... 20mA
Forward Current .......................................................... 10mA
Maximum Output Voltage (LM4041-ADJ) ...................... 15V
Lead Temperature
Vapor phase (60s) ............................................... 215°C
Infrared (15s) ....................................................... 220°C
(3)
Power Dissipation (TA = 25°C) .............................. 306mW
Storage Temperature (Ts)......................... –65°C to +150°C
ESD Susceptibility
(4)
Human Body Model .............................................. 2kV
(4)
Machine Model .................................................... 200V
Operating Temperature Range (TA) ............ –40°C to +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
Thermal Resistance
3-Pin SOT-23 (ΘJA) .......................................... 326°C/W
LM4040-2.5 Electrical Characteristics(5)
TA = Operating Temperature Range, bold values indicate TA = TJ = –40°C to +85°C, unless noted.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Units
LM4040C
Reverse Breakdown Voltage
VR
Reverse Breakdown Voltage
(6)
Tolerance
IRMIN
Minimum Operating Current
ΔVR/ΔT
Average Reverse Breakdown
Voltage Temperature
Coefficient
ΔVR/ΔIR
Reverse Breakdown Voltage
Change with Operating Current
Change
2.500
IR = 100µA
45
IR = 10mA
±20
IR = 1mA
±15
IR = 100µA
±15
0.3
IRMIN ≤ IR ≤1mA
2.5
1mA ≤ IR ≤ 15mA
V
±12
mV
±29
mV
60
µA
65
µA
ppm/°C
±100
ppm/°C
ppm/°C
0.8
mV
1.0
mV
6.0
mV
8.0
mV
0.9
Ω
ZR
Reverse Dynamic Impedance
IR = 1mA, f = 120Hz, IAC = 0.1IR
0.3
eN
Wideband Noise
IR = 100µA, 10Hz ≤ f ≤ 10kHz
35
µVRMS
ΔVR
Reverse Breakdown Voltage
Long Term Stability
t = 1000hrs., T = 25°C ±0.1°C, IR = 100µA
120
ppm
Notes:
1. Exceeding the absolute maximum ratings may damage the device.
2. The device is not guaranteed to function outside its operating ratings.
3. The maximum power dissipation must be derated at elevated temperatures and is dictated by TJMAX (maximum junction temperature), ƟJA (junction
to ambient thermal resistance), and TA (ambient temperature). The maximum allowable power dissipation at any temperature is PDMAX = (TJMAX –
TA)/ ƟJA 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, when board-mounted, is 326°C/W for the SOT-23 package.
4. Devices are ESD sensitive. Handling precautions are recommended. Human body model, 1.5kΩ in series with 100pF. The machine model is a
200pF capacitor discharged directly into each pin.
5. Specification for packaged product only.
6. The boldface (overtemperature) 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 overtemperature tolerance for the different grades follows:
a. C-grade: ±1.15% = ±0.5% ±100ppm/°C × 65°C
b. D-grade: ±1.98% = ±1.0% ±150ppm/°C × 65°C
Example: The C-grade LM4040-2.5 has an overtemperature Reverse Breakdown Voltage tolerance of ±2.5 × 1.15% = ±29mV.
June 24, 2014
3
Revision 3.0
Micrel, Inc.
LM4040/LM4041
LM4040-2.5 Electrical Characteristics(5) (Continued)
TA = Operating Temperature Range, bold values indicate TA = TJ = –40°C to +85°C, unless noted.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Units
LM4040D
Reverse Breakdown Voltage
VR
Reverse Breakdown Voltage
(6)
Tolerance
IRMIN
Minimum Operating Current
ΔVR/ΔT
Average Reverse Breakdown
Voltage Temperature
Coefficient
ΔVR/ΔIR
Reverse Breakdown Voltage
Change with Operating Current
Change
2.500
IR = 100µA
45
IR = 10mA
±20
IR = 1mA
±15
IR = 100µA
±15
0.3
IRMIN ≤ IR ≤1mA
2.5
1mA ≤ IR ≤ 15mA
V
±25
mV
±49
mV
65
µA
70
µA
ppm/°C
±150
ppm/°C
ppm/°C
1.0
mV
1.2
mV
8.0
mV
10.0
mV
1.1
Ω
ZR
Reverse Dynamic Impedance
IR = 1mA, f = 120Hz, IAC = 0.1IR
0.3
eN
Wideband Noise
IR = 100µA, 10Hz ≤ f ≤ 10kHz
35
µVRMS
ΔVR
Reverse Breakdown Voltage
Long Term Stability
t = 1000hrs., T = 25°C ±0.1°C, IR = 100µA
120
ppm
LM4040-4.1 Electrical Characteristics(5)
TA = Operating Temperature Range, bold values indicate TA = TJ = –40°C to +85°C, unless noted.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Units
LM4040C
Reverse Breakdown Voltage
VR
Reverse Breakdown Voltage
(6)
Tolerance
IRMIN
Minimum Operating Current
ΔVR/ΔT
Average Reverse Breakdown
Voltage Temperature
Coefficient
ΔVR/ΔIR
Reverse Breakdown Voltage
Change with Operating Current
Change
4.096
IR = 100µA
50
IR = 10mA
±30
IR = 1mA
±20
IR = 100µA
±20
0.5
IRMIN ≤ IR ≤1mA
3.0
1mA ≤ IR ≤ 15mA
V
±20
mV
±47
mV
68
µA
73
µA
ppm/°C
±100
ppm/°C
ppm/°C
0.9
mV
1.2
mV
7.0
mV
10.0
mV
Reverse Dynamic Impedance
IR = 1mA, f = 120Hz, IAC = 0.1IR
0.5
eN
Wideband Noise
IR = 100µA, 10Hz ≤ f ≤ 10kHz
80
µVRMS
ΔVR
Reverse Breakdown Voltage
Long Term Stability
t = 1000hrs., T = 25°C ±0.1°C, IR = 100µA
120
ppm
June 24, 2014
4
1.0
Ω
ZR
Revision 3.0
Micrel, Inc.
LM4040/LM4041
LM4040-4.1 Electrical Characteristics(5) (Continued)
TA = Operating Temperature Range, bold values indicate TA = TJ = –40°C to +85°C, unless noted.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Units
LM4040D
Reverse Breakdown Voltage
VR
Reverse Breakdown Voltage
(6)
Tolerance
IRMIN
Minimum Operating Current
ΔVR/ΔT
Average Reverse Breakdown
Voltage Temperature
Coefficient
ΔVR/ΔIR
Reverse Breakdown Voltage
Change with Operating Current
Change
4.096
IR = 100µA
50
IR = 10mA
±30
IR = 1mA
±20
IR = 100µA
±20
0.5
IRMIN ≤ IR ≤1mA
3.0
1mA ≤ IR ≤ 15mA
V
±41
mV
±81
mV
73
µA
78
µA
ppm/°C
±150
ppm/°C
ppm/°C
1.2
mV
1.5
mV
9.0
mV
13.0
mV
1.3
Ω
ZR
Reverse Dynamic Impedance
IR = 1mA, f = 120Hz, IAC = 0.1IR
0.5
eN
Wideband Noise
IR = 100µA, 10Hz ≤ f ≤ 10kHz
80
µVRMS
ΔVR
Reverse Breakdown Voltage
Long Term Stability
t = 1000hrs., T = 25°C ±0.1°C, IR = 100µA
120
ppm
LM4040-5.0 Electrical Characteristics(5)
TA = Operating Temperature Range, bold values indicate TA = TJ = –40°C to +85°C, unless noted.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Units
LM4040C
Reverse Breakdown Voltage
VR
Reverse Breakdown Voltage
(6)
Tolerance
IRMIN
Minimum Operating Current
ΔVR/ΔT
Average Reverse Breakdown
Voltage Temperature
Coefficient
ΔVR/ΔIR
Reverse Breakdown Voltage
Change with Operating Current
Change
5.000
IR = 100µA
54
IR = 10mA
±30
IR = 1mA
±20
IR = 100µA
±20
0.5
IRMIN ≤ IR ≤1mA
3.5
1mA ≤ IR ≤ 15mA
V
±25
mV
±58
mV
74
µA
80
µA
ppm/°C
±100
ppm/°C
ppm/°C
1.0
mV
1.4
mV
8.0
mV
12.0
mV
Reverse Dynamic Impedance
IR = 1mA, f = 120Hz, IAC = 0.1IR
0.5
eN
Wideband Noise
IR = 100µA, 10Hz ≤ f ≤ 10kHz
80
µVRMS
ΔVR
Reverse Breakdown Voltage
Long Term Stability
t = 1000hrs., T = 25°C ±0.1°C, IR = 100µA
120
ppm
June 24, 2014
5
1.1
Ω
ZR
Revision 3.0
Micrel, Inc.
LM4040/LM4041
LM4040-5.0 Electrical Characteristics(5) (Continued)
TA = Operating Temperature Range, bold values indicate TA = TJ = –40°C to +85°C, unless noted.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Units
LM4040D
Reverse Breakdown Voltage
VR
Reverse Breakdown Voltage
(6)
Tolerance
IRMIN
Minimum Operating Current
ΔVR/ΔT
Average Reverse Breakdown
Voltage Temperature
Coefficient
ΔVR/ΔIR
Reverse Breakdown Voltage
Change with Operating Current
Change
5.000
IR = 100µA
54
IR = 10mA
±30
IR = 1mA
±20
IR = 100µA
±20
0.5
IRMIN ≤ IR ≤1mA
3.5
1mA ≤ IR ≤ 15mA
V
±50
mV
±99
mV
79
µA
85
µA
ppm/°C
±150
ppm/°C
ppm/°C
1.3
mV
1.8
mV
10.0
mV
15.0
mV
1.5
Ω
ZR
Reverse Dynamic Impedance
IR = 1mA, f = 120Hz, IAC = 0.1IR
0.5
eN
Wideband Noise
IR = 100µA, 10Hz ≤ f ≤ 10kHz
80
µVRMS
ΔVR
Reverse Breakdown Voltage
Long Term Stability
t = 1000hrs., T = 25°C ±0.1°C, IR = 100µA
120
ppm
LM4041-1.2 Electrical Characteristics(5)
TA = Operating Temperature Range, bold values indicate TA = TJ = –40°C to +85°C, unless noted.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Units
LM4041C
Reverse Breakdown Voltage
VR
Reverse Breakdown Voltage
(6)
Tolerance
IRMIN
Minimum Operating Current
ΔVR/ΔT
Average Reverse Breakdown
Voltage Temperature
Coefficient
ΔVR/ΔIR
Reverse Breakdown Voltage
Change with Operating Current
Change
1.225
IR = 100µA
45
IR = 10mA
±20
IR = 1mA
±15
IR = 100µA
±15
0.7
IRMIN ≤ IR ≤1mA
4.0
1mA ≤ IR ≤ 15mA
V
±6
mV
±14
mV
60
µA
65
µA
ppm/°C
±100
ppm/°C
ppm/°C
1.5
mV
2.0
mV
6.0
mV
8.0
mV
Reverse Dynamic Impedance
IR = 1mA, f = 120Hz, IAC = 0.1IR
0.5
eN
Wideband Noise
IR = 100µA, 10Hz ≤ f ≤ 10kHz
20
µVRMS
ΔVR
Reverse Breakdown Voltage
Long Term Stability
t = 1000hrs., T = 25°C ±0.1°C, IR = 100µA
120
ppm
June 24, 2014
6
1.5
Ω
ZR
Revision 3.0
Micrel, Inc.
LM4040/LM4041
LM4041-1.2 Electrical Characteristics(5) (Continued)
TA = Operating Temperature Range, bold values indicate TA = TJ = –40°C to +85°C, unless noted.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Units
LM4041D
Reverse Breakdown Voltage
VR
Reverse Breakdown Voltage
(6)
Tolerance
IRMIN
Minimum Operating Current
ΔVR/ΔT
Average Reverse Breakdown
Voltage Temperature
Coefficient
ΔVR/ΔIR
Reverse Breakdown Voltage
Change with Operating Current
Change
1.225
IR = 100µA
45
IR = 10mA
±20
IR = 1mA
±15
IR = 100µA
±15
0.7
IRMIN ≤ IR ≤1mA
2.5
1mA ≤ IR ≤ 15mA
V
±12
mV
±24
mV
65
µA
70
µA
ppm/°C
±150
ppm/°C
ppm/°C
2.0
mV
2.5
mV
8.0
mV
10.0
mV
2.0
Ω
ZR
Reverse Dynamic Impedance
IR = 1mA, f = 120Hz, IAC = 0.1IR
0.5
eN
Wideband Noise
IR = 100µA, 10Hz ≤ f ≤ 10kHz
20
µVRMS
ΔVR
Reverse Breakdown Voltage
Long Term Stability
t = 1000hrs., T = 25°C ±0.1°C, IR = 100µA
120
ppm
June 24, 2014
7
Revision 3.0
Micrel, Inc.
LM4040/LM4041
LM4041-ADJ Electrical Characteristics(5)
TA = Operating Temperature Range, bold values indicate TA = TJ = –40°C to +85°C, unless noted.
Symbol
Parameter
Condition
Min.
Reverse Breakdown Voltage
IR = 100µA, VOUT = 5V
Reverse Breakdown Voltage
(6)
Tolerance
IR = 100µA
Typ.
Max.
Units
LM4041C
VR
IRMIN
45
Minimum Operating Current
IRMIN ≤ IR ≤ 1mA, VOUT ≥ 1.6V
ΔVREF/
ΔIR
1.233
(7)
Reference Voltage Change with
Operating Current
(7)
1mA ≤ IR ≤ 15mA, VOUT ≥ 1.6V
ΔVREF/
ΔVO
Reference Voltage Change with
Output Voltage Change
IFB
Feedback Current
ΔVREF/ΔT
Average Reference Voltage
Temperature Coefficient
ZOUT
Dynamic Output Impedance
0.7
2.0
-1.55
IR = 1mA
60
V
±6.2
mV
±14
mV
60
µA
65
µA
1.5
mV
2.0
mV
4.0
mV
6.0
mV
-2.0
mV/V
-2.5
mV/V
100
nA
120
nA
VOUT = 5V, IR = 10mA
±20
VOUT = 5V, IR = 1mA
±15
VOUT = 5V, IR = 100µA
±15
ppm/°C
IR = 1mA, f = 120Hz, IAC = 0.1IR
VOUT = VREF
0.3
Ω
VOUT = 10V
ppm/°C
±100
2.0
ppm/°C
Ω
eN
Wideband Noise
IR = 100µA, 10Hz ≤ f ≤ 10kHz
20
µVRMS
ΔVR
Reverse Breakdown Voltage
Long Term Stability
t = 1000hrs, T = 25°C ±0.1°C, IR = 100µA
120
ppm
Note:
7. 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.
June 24, 2014
8
Revision 3.0
Micrel, Inc.
LM4040/LM4041
LM4041-ADJ Electrical Characteristics(5)
TA = Operating Temperature Range, bold values indicate TA = TJ = –40°C to +85°C, unless noted.
Symbol
Parameter
Condition
Min.
Reverse Breakdown Voltage
IR = 100µA, VOUT = 5V
Reverse Breakdown Voltage
(6)
Tolerance
IR = 100µA
Typ.
Max.
Units
LM4041D
VR
IRMIN
45
Minimum Operating Current
IRMIN ≤ IR ≤ 1mA, VOUT ≥ 1.6V
ΔVREF/
ΔIR
1.233
(7)
Reference Voltage Change with
Operating Current
(7)
1mA ≤ IR ≤ 15mA, VOUT ≥ 1.6V
ΔVREF/
ΔVO
Reference Voltage Change with
Output Voltage Change
IFB
Feedback Current
ΔVREF/ΔT
Average Reference Voltage
Temperature Coefficient
ZOUT
Dynamic Output Impedance
0.7
2.0
-1.55
IR = 1mA
60
V
±12
mV
±24
mV
65
µA
70
µA
2.0
mV
2.5
mV
6.0
mV
8.0
mV
-2.5
mV/V
-3.0
mV/V
150
nA
200
nA
VOUT = 5V, IR = 10mA
±20
VOUT = 5V, IR = 1mA
±15
VOUT = 5V, IR = 100µA
±15
ppm/°C
IR = 1mA, f = 120Hz, IAC = 0.1IR
VOUT = VREF
0.3
Ω
VOUT = 10V
ppm/°C
±150
2.0
ppm/°C
Ω
eN
Wideband Noise
IR = 100µA, 10Hz ≤ f ≤ 10kHz
20
µVRMS
ΔVR
Reverse Breakdown Voltage
Long Term Stability
t = 1000hrs, T = 25°C ±0.1°C, IR = 100µA
120
ppm
June 24, 2014
9
Revision 3.0
Micrel, Inc.
LM4040/LM4041
Test Circuit
LM4040
LM4041
Reverse Characteristics Test Circuit
Output Impedance vs. Frequency Test Circuit
Large Signal Response Test Circuit
June 24, 2014
10
Revision 3.0
Micrel, Inc.
LM4040/LM4041
LM4040 Typical Characteristics
June 24, 2014
11
Revision 3.0
Micrel, Inc.
LM4040/LM4041
LM4041 Typical Characteristics
June 24, 2014
12
Revision 3.0
Micrel, Inc.
LM4040/LM4041
Functional Diagrams
LM4040, LM4041 Fixed
June 24, 2014
LM4041 Adjustable
13
Revision 3.0
Micrel, Inc.
LM4040/LM4041
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 following equation:
Applications Information
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. The
LM4041-ADJs use pin 3 as the (–) output.
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:
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). Because 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.
VREF = VO (ΔVREF/ΔVO) + VY
June 24, 2014
Eq. 3
where VO is the desired output voltage. ΔVREF/ΔVO is
found in the Electrical Characteristics section and is
typically –1.3mV/V and VY is equal to 1.233V. Replace
the value of VREF in Equation 2 with the value VREF found
using Equation 3.
Note that actual output voltage can deviate from that
predicted using the typical ΔVREF/ΔVO in Equation 3; for
C-grade 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.
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)
Eq. 2
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 Cgrade 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 ΔVREF/ΔVO will work in most
cases, requiring no further adjustment.
Eq. 1
14
Revision 3.0
Micrel, Inc.
LM4040/LM4041
Typical Application Circuits
Figure 1. Voltage Level Detector
Figure 2. Voltage Level Detector
Figure 3. Fast Positive Clamp
2.4V + ΔVD1
Figure 4. Bidirectional Clamp
±2.4V
Figure 5. Bidirectional Adjustable Clamp
±18V to ±2.4V
Figure 6. Bidirectional Adjustable Clamp
±2.4V to ±6V
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Revision 3.0
Micrel, Inc.
LM4040/LM4041
Typical Application Circuits (Continued)
Figure 7. Floating Current Detector
Figure 8. Current Source
Figure 9. Precision Floating Current Detector
June 24, 2014
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Revision 3.0
Micrel, Inc.
LM4040/LM4041
Package Information(8)
3-Pin SOT-23 (M3)
Note:
8. Package information is correct as of the publication date. For updates and most current information, go to www.micrel.com.
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