General Description
The LM4040 is a precision two-terminal shunt mode,
bandgap voltage reference available in fixed reverse
breakdown voltages of 2.048V, 2.500V, 3.000V, 3.3V,
4.096V, and 5.000V. Ideal for space-critical applica-
tions, the LM4040 is offered in the subminiature 3-pin
SC70 surface-mount package (1.8mm 1.8mm), 50%
smaller than comparable devices in SOT23 surface-
mount packages (SOT23 versions are also available).
Laser-trimmed resistors ensure precise initial accuracy.
With a 100ppm/°C temperature coefficient, the device
is offered in four grades of initial accuracy ranging from
0.1% to 1%. The LM4040 has a 60µA to 15mA shunt
current capability with low dynamic impedance, ensur-
ing stable reverse breakdown voltage accuracy over a
wide range of operating temperatures and currents.
The LM4040 does not require an external stabilizing
capacitor while ensuring stability with any capacitive
load.
The LM4040 is guaranteed over the temperature range
of -40°C to +125°C.
For a 1.225V output version, refer to the LM4041 data
sheet.
________________________Applications
Portable, Battery-Powered Equipment
Notebook Computers
Cell Phones
Industrial Process Controls
Features
oUltra-Small 3-Pin SC70 Package
o0.1% (max) Initial Accuracy
o100ppm/°C (max) Temperature Coefficient
Guaranteed over -40°C to +125°C Temperature
Range
oWide Operating Current Range: 60µA to 15mA
oLow 28µVRMS Output Noise (10Hz to 10kHz)
o2.048V, 2.500V, 3.000V, 3.3V, 4.096V, and 5.000V
Fixed Reverse Breakdown Voltages
oNo Output Capacitors Required
oTolerates Capacitive Loads
LM4040
Improved Precision Micropower Shunt Voltage
Reference with Multiple Reverse Breakdown Voltages
________________________________________________________________
Maxim Integrated Products
1
-
1
3 N.C.*
+
+
LM4040
SC70-3/SOT23-3
TOP VIEW
2
*PIN 3 MUST BE LEFT UNCONNECTED
OR CONNECTED TO PIN 2.
PART TEMP RANGE PIN-
PACKAGE
OUTPUT
VOLTAGE
(V)
LM 4040_IM 3-2.1+T -40°C to +85°C 3 SOT23 2.048
LM 4040_IX 3-2.1+T -40°C to +85°C 3 SC70 2.048
LM 4040_E M 3-2.1+T -40°C to +125°C 3 SOT23 2.048
LM 4040_E X 3-2.1+T -40°C to +125°C 3 SC70 2.048
LM 4040_IM 3-2.5+T -40°C to +85°C 3 SOT23 2.500
LM 4040_IX 3-2.5+T -40°C to +85°C 3 SC70 2.500
LM 4040_IM 3-2.5/V + T -40°C to +85°C 3 SC70 2.500
LM 4040_E M 3-2.5+T -40°C to +125°C 3 SOT23 2.500
LM4040_EM3-2.5/V+T -40°C to +125°C 3 SOT23 2.500
LM 4040_E X 3-2.5+T -40°C to +125°C 3 SC70 2.500
LM 4040_IM 3-3.0+T -40°C to +85°C 3 SOT23 3.000
LM 4040_IX 3-3.0+T -40°C to +85°C 3 SC70 3.000
LM 4040_E X 3-3.0+T -40°C to +125°C 3 SC70 3.000
LM 4040_E X 3-3.3+T -40°C to +125°C 3 SC70 3.300
LM 4040_IM 3-4.1+T -40°C to +85°C 3 SOT23 4.096
LM 4040_IX 3-4.1+T -40°C to +85°C 3 SC70 4.096
LM4040_EM3-4.1 -40°C to +125°C 3 SOT23 4.096
LM4040_EM3-4.1/V+T -40°C to +125°C 3 SOT23 4.096
LM4040_EX3-4.1+T -40°C to +125°C 3 SC70 4.096
LM4040_IM3-5.0+T -40°C to +85°C 3 SOT23 5.000
LM4040_IX3-5.0+T -40°C to +85°C 3 SC70 5.000
LM4040_EM3-5.0+T -40°C to +125°C 3 SOT23 5.000
LM 4040_E M 3-5.0/V + T -40°C to +125°C 3 SOT23 5.000
LM4040_EX3-5.0+T -40°C to +125°C 3 SC70 5.000
Pin Configuration
Selector Guide
19-1787; Rev 7; 11/11
Ordering Information appears at end of data sheet.
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
+
Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
LM4040
Improved Precision Micropower Shunt Voltage
Reference with Multiple Reverse Breakdown Voltages
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS—2.048V
(IR= 100µA, TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
Reverse Current (cathode to anode) ..................................20mA
Forward Current (anode to cathode) ..................................10mA
Continuous Power Dissipation (TA= +70°C)
3-Pin SC70 (derate 2.17mW/°C above +70°C)............174mW
3-Pin SOT23 (derate 4.01mW/°C above +70°C)..........320mW
Operating Temperature Range
LM4040_I_ _ _..................................................-40°C to +85°C
LM4040_E_ _ _ ..............................................-40°C to +125°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature......................................................+150°C
Lead Temperature (soldering, 10s)..................................+300°C
Soldering Temperature (reflow) .......................................+260°C
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
LM4040A (0.1%) 2.046 2.048 2.050
LM4040B (0.2%) 2.044 2.048 2.052
LM4040C (0.5%) 2.038 2.048 2.058
Reverse Breakdown Voltage VRTA = +25°C
LM4040D (1.0%) 2.028 2.048 2.068
V
LM4040A ±2.0 ±15
LM4040B ±4.0 ±17
LM4040C ±10 ±23
Reverse Breakdown Voltage
Tolerance (Note 2) VR
LM4040D ±20 ±41
mV
LM4040A/B/C 45 65
Minimum Operating Current IRMIN LM4040D 45 70 µA
IR = 10mA ±20
LM4040A/B/C ±15 ±100
IR = 1mA LM4040D ±15 ±150
Average Reverse Voltage
Temperature Coefficient
(Notes 2 and 3)
∆VR/∆T
IR = 100µA ±15
ppm/°C
LM4040A/B/C 0.3 1.0
IRMIN ≤ IR ≤ 1mA LM4040D 0.3 1.2
LM4040A/B/C 2.5 8.0
Reverse Breakdown Voltage
Change with Operating
Current Change 1mA ≤ IR ≤ 15mA LM4040D 2.5 10.0
mV
LM4040A/B 0.3 0.8
LM4040C 0.3 0.9
Reverse Dynamic
Impedance (Note 3) ZRIR = 1mA, f = 120Hz,
IAC = 0.1IRLM4040D 0.3 1.1
Ω
Wideband Noise eNIR = 100µA, 10Hz ≤ f ≤ 10kHz 28 µVRMS
Reverse Breakdown Voltage
Long-Term Stability ∆VRT = 1000h 120 ppm
LM4040
Improved Precision Micropower Shunt Voltage
Reference with Multiple Reverse Breakdown Voltages
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS—2.500V
(IR= 100µA, TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
LM4040A (0.1%) 2.4975 2.5000 2.5025
LM4040B (0.2%) 2.4950 2.5000 2.5050
LM4040C (0.5%) 2.4875 2.5000 2.5125
Reverse Breakdown Voltage VRTA = +25°C
LM4040D (1.0%) 2.4750 2.5000 2.5250
V
LM4040A ±2.0 ±19
LM4040B ±4.0 ±21
LM4040C ±10 ±29
Reverse Breakdown Voltage
Tolerance (Note 2) VR
LM4040D ±20 ±49
mV
LM4040A/B/C 45 65
Minimum Operating Current IRMIN LM4040D 45 70 µA
IR = 10mA ±20
LM4040A/B/C ±15 ±100
IR = 1mA LM4040D ±15 ±150
Average Reverse Voltage
Temperature Coefficient
(Notes 2 and 3)
∆VR/∆T
IR = 100µA ±15
ppm/°C
LM4040A/B/C 0.3 1.0
IRMIN ≤ IR ≤ 1mA LM4040D 0.4 1.2
LM4040A/B/C 2.5 8.0
Reverse Breakdown Voltage
Change with Operating
Current Change 1mA ≤ IR ≤ 15mA LM4040D 2.5 10.0
mV
LM4040A/B 0.3 0.8
LM4040C 0.3 0.9
Reverse Dynamic
Impedance (Note 3) ZRIR = 1mA, f = 120Hz,
IAC = 0.1IRLM4040D 0.3 1.1
Ω
Wideband Noise eNIR = 100µA, 10Hz ≤ f ≤ 10kHz 35 µVRMS
Reverse Breakdown Voltage
Long-Term Stability ∆VRT = 1000h 120 ppm
LM4040
Improved Precision Micropower Shunt Voltage
Reference with Multiple Reverse Breakdown Voltages
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS—3.000V
(IR= 100µA, TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
LM4040A (0.1%) 2.997 3.000 3.003
LM4040B (0.2%) 2.994 3.000 3.006
LM4040C (0.5%) 2.985 3.000 3.015
Reverse Breakdown Voltage VRTA = +25°C
LM4040D (1.0%) 2.970 3.000 3.030
V
LM4040A ±3.0 ±22
LM4040B ±6.0 ±26
LM4040C ±15 ±34
Reverse Breakdown Voltage
Tolerance (Note 2) VR
LM4040D ±30 ±59
mV
LM4040A/B/C 45 67
Minimum Operating Current IRMIN LM4040D 45 70 µA
IR = 10mA ±20
LM4040A/B/C ±15 ±100
IR = 1mA LM4040D ±15 ±150
Average Reverse Voltage
Temperature Coefficient
(Notes 2 and 3)
∆VR/∆T
IR = 100µA ±15
ppm/°C
LM4040A/B/C 0.3 1.0
IRMIN ≤ IR ≤ 1mA LM4040D 0.3 1.2
LM4040A/B/C 2.5 8.0
Reverse Breakdown Voltage
Change with Operating
Current Change 1mA ≤ IR ≤ 15mA LM4040D 2.5 10.0
mV
LM4040A/B 0.3 0.8
LM4040C 0.3 0.9
Reverse Dynamic
Impedance (Note 3) ZRIR = 1mA, f = 120Hz,
IAC = 0.1IRLM4040D 0.3 1.1
Ω
Wideband Noise eNIR = 100µA, 10Hz ≤ f ≤ 10kHz 45 µVRMS
Reverse Breakdown Voltage
Long-Term Stability ∆VRT = 1000h 120 ppm
LM4040
Improved Precision Micropower Shunt Voltage
Reference with Multiple Reverse Breakdown Voltages
_______________________________________________________________________________________ 5
ELECTRICAL CHARACTERISTICS—3.300V
(IR= 100µA, TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
LM4040A (0.1%) 3.2967 3.3000 3.3033
LM4040B (0.2%) 3.2934 3.3000 3.3066
LM4040C (0.5%) 3.2835 3.3000 3.3165
Reverse Breakdown Voltage VRTA = +25°C
LM4040D (1.0%) 3.2670 3.3000 3.3330
V
LM4040A ±3.0 ±22
LM4040B ±6.0 ±26
LM4040C ±15 ±34
Reverse Breakdown Voltage
Tolerance (Note 2) VR
LM4040D ±30 ±59
mV
LM4040A/B/C 45 67
Minimum Operating Current IRMIN LM4040D 45 70 µA
IR = 10mA ±20
LM4040A/B/C ±15 ±100
IR = 1mA LM4040D ±15 ±150
Average Reverse Voltage
Temperature Coefficient
(Notes 2 and 3)
∆VR/∆T
IR = 100µA ±15
ppm/°C
LM4040A/B/C 0.3 1.0
IRMIN ≤ IR ≤ 1mA LM4040D 0.3 1.2
LM4040A/B/C 2.5 8.0
Reverse Breakdown Voltage
Change with Operating
Current Change 1mA ≤ IR ≤ 15mA LM4040D 2.5 10.0
mV
LM4040A/B 0.3 0.8
LM4040C 0.3 0.9
Reverse Dynamic
Impedance (Note 3) ZRIR = 1mA, f = 120Hz,
IAC = 0.1IRLM4040D 0.3 1.1
Ω
Wideband Noise eNIR = 100µA, 10Hz ≤ f ≤ 10kHz 50 µVRMS
Reverse Breakdown Voltage
Long-Term Stability ∆VRT = 1000h 120 ppm
LM4040
Improved Precision Micropower Shunt Voltage
Reference with Multiple Reverse Breakdown Voltages
6 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS—4.096V
(IR= 100µA, TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
LM4040A (0.1%) 4.092 4.096 4.100
LM4040B (0.2%) 4.088 4.096 4.104
LM4040C (0.5%) 4.076 4.096 4.116
Reverse Breakdown Voltage VRTA = +25°C
LM4040D (1.0%) 4.055 4.096 4.137
V
LM4040A ±4.1 ±31
LM4040B ±8.2 ±35
LM4040C ±20 ±47
Reverse Breakdown Voltage
Tolerance (Note 2) VR
LM4040D ±41 ±81
mV
LM4040A/B/C 50 73
Minimum Operating Current IRMIN LM4040D 50 78 µA
IR = 10mA ±30
LM4040A/B/C ±20 ±100
IR = 1mA LM4040D ±20 ±150
Average Reverse Voltage
Temperature Coefficient
(Notes 2 and 3)
∆VR/∆T
IR = 100µA ±15
ppm/°C
LM4040A/B/C 0.5 1.2
IRMIN ≤ IR ≤ 1mA LM4040D 0.5 1.5
LM4040A/B/C 3.0 10.0
Reverse Breakdown Voltage
Change with Operating
Current Change 1mA ≤ IR ≤ 15mA LM4040D 3.0 13.0
mV
LM4040A/B/C 0.5 1.0
Reverse Dynamic
Impedance (Note 3) ZRIR = 1mA, f = 120Hz,
IAC = 0.1IRLM4040D 0.5 1.3
Ω
Wideband Noise eNIR = 100µA, 10Hz ≤ f ≤ 10kHz 64 µVRMS
Reverse Breakdown Voltage
Long-Term Stability ∆VRT = 1000h 120 ppm
LM4040
Improved Precision Micropower Shunt Voltage
Reference with Multiple Reverse Breakdown Voltages
_______________________________________________________________________________________ 7
Note 1: All devices are 100% production tested at TA= +25°C and are guaranteed by design for TA= TMIN to TMAX, as specified.
Note 2: The overtemperature limit for Reverse Breakdown Voltage Tolerance is defined as the room-temperature Reverse
Breakdown Voltage Tolerance ±[(∆VR/∆T)(max∆T)(VR)], where ∆VR/∆T is the VRtemperature coefficient, max∆T is the maxi-
mum difference in temperature from the reference point of +25°C to TMIN or TMAX, and VRis the reverse breakdown volt-
age. The total overtemperature tolerance for the different grades in the temperature range where max∆T = +65°C is shown
below:
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
The total over-temperature tolerance for the different grades in the extended temperature range where max ∆T = +100°C is
shown below:
A grade: ±1.1% = ±0.1% ±100ppm/°C 100°C
B grade: ±1.2% = ±0.2% ±100ppm/°C 100°C
C grade: ±1.5% = ±0.5% ±100ppm/°C 100°C
D grade: ±2.5% = ±1.0% ±150ppm/°C 100°C
Therefore, as an example, the A-grade LM4040-2.5 has an over-temperature reverse breakdown voltage tolerance of ±2.5V
0.75% = ±19mV.
Note 3: Guaranteed by design.
ELECTRICAL CHARACTERISTICS—5.000V
(IR= 100µA, TA= TMIN to TMAX, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
LM4040A (0.1%) 4.995 5.000 5.005
LM4040B (0.2%) 4.990 5.000 5.010
LM4040C (0.5%) 4.975 5.000 5.025
Reverse Breakdown Voltage VRTA = +25°C
LM4040D (1.0%) 4.950 5.000 5.050
V
LM4040A ±5.0 ±38
LM4040B ±10 ±43
LM4040C ±25 ±58
Reverse Breakdown Voltage
Tolerance (Note 2) VR
LM4040D ±50 ±99
mV
LM4040A/B/C 54 80
Minimum Operating Current IRMIN LM4040D 54 85 µA
IR = 10mA ±30
LM4040A/B/C ±20 ±100
IR = 1mA LM4040D ±20 ±150
Average Reverse Voltage
Temperature Coefficient
(Notes 2 and 3)
∆VR/∆T
IR = 100µA ±15
ppm/°C
LM4040A/B/C 0.5 1.4
IRMIN ≤ IR ≤ 1mA LM4040D 0.5 1.8
LM4040A/B/C 3.5 12.0
Reverse Breakdown Voltage
Change with Operating
Current Change 1mA ≤ IR ≤ 15mA LM4040D 3.5 15.0
mV
LM4040A/B/C 0.5 1.1
Reverse Dynamic
Impedance (Note 3) ZRIR = 1mA, f = 120Hz,
IAC = 0.1IRLM4040D 0.5 1.5
Ω
Wideband Noise eNIR = 100µA, 10Hz ≤ f ≤ 10kHz 80 µVRMS
Reverse Breakdown Voltage
Long-Term Stability ∆VRT = 1000h 120 ppm
LM4040
Improved Precision Micropower Shunt Voltage
Reference with Multiple Reverse Breakdown Voltages
8 _______________________________________________________________________________________
LM4040-2.5V
TEMPERATURE DRIFT
LM4040-02
TEMPERATURE (°C)
REFERENCE VOLTAGE CHANGE (mV)
1007550250-25
-4
-3
-2
-1
0
1
-5
-50 125
LM4040-5.0V
TEMPERATURE DRIFT
LM4040 toc03
TEMPERATURE (°C)
REFERENCE VOLTAGE CHANGE (mV)
1007550250-25
-15
-10
-5
0
5
-20
-50 125
Typical Operating Characteristics
(IR= 100µA, SC70-3 package, TA= +25°C, unless otherwise noted.)
0
1
2
3
4
5
6
050100
REVERSE CHARACTERISTICS AND
MINIMUM OPERATING CURRENT
LM4040-01
REVERSE CURRENT (µA)
REVERSE VOLTAGE (V)
LM4040_I_3-5.0
LM4040_I_3-4.1
LM4040_I_3-3.0
LM4040_I_3-2.5
LM4040_I_3-2.1
LM4040-5.0V
REVERSE VOLTAGE vs. ISHUNT
LM4040 toc05
ISHUNT (mA)
REVERSE VOLTAGE CHANGE (mV)
15105
1
2
3
4
5
6
0
020
TA = -40°C
TA = +125°C
TA = +85°C
TA = +25°C
LM4040-2.5V
REVERSE VOLTAGE vs. ISHUNT
LM4040-04
ISHUNT (mA)
REVERSE VOLTAGE CHANGE (mV)
15105
1
2
3
4
5
0
020
TA = +125°C
TA = -40°C
TA = +25°C
TA = +85°C
LM4040
Improved Precision Micropower Shunt Voltage
Reference with Multiple Reverse Breakdown Voltages
_______________________________________________________________________________________ 9
VGEN
VR AC-COUPLED
+25µA
-25µA
10mV/div
LM4040-5.0V
LOAD-TRANSIENT RESPONSE
LM4040-07
40µs/div
ISHUNT = 100µA ± 25µA
RL = 100kΩ, SEE FIGURE 1
VGEN
VR AC-COUPLED
+250µA
-250µA
10mV/div
LM4040
-
2
.
5V
LOAD-TRANSIENT RESPONSE
LM4040-08
10µs/div
ISHUNT = 1mA ± 250µA
RL = 10kΩ, SEE FIGURE 1
Typical Operating Characteristics (continued)
(IR= 100µA, SC70 package, TA= +25°C, unless otherwise noted.)
VGEN
VR AC-COUPLED
+25µA
-25µA
2mV/div
LM4040-2.5V
LOAD-TRANSIENT RESPONSE
LM4040-06
10µs/div
CH1: VGEN 2V/div
CH2: VR AC-COUPLED 2mV/div
ISHUNT = 100µA ± 25µA, RL = 100kΩ, SEE FIGURE 1
VGEN
VR AC-COUPLED
+2.5mA
-2.5mA
20mV/div
LM4040-2.5V
LOAD-TRANSIENT RESPONSE
LM4040-10
10µs/div
ISHUNT = 10mA ± 2.5mA
RL = 1kΩ, SEE FIGURE 1
VGEN
VR AC-COUPLED
+2.5mA
-2.5mA
20mV/div
LM4040-5.0V
LOAD-TRANSIENT RESPONSE
LM4040-11
10µs/div
ISHUNT = 10mA ± 2.5mA
RL = 1kΩ, SEE FIGURE 1
VGEN
VR AC-COUPLED
+250µA
-250µA
10mV/div
LM4040-5.0V
LOAD-TRANSIENT RESPONSE
LM4040-09
10µs/div
ISHUNT = 1mA ± 250µA
RL = 10kΩ, SEE FIGURE 1
1kΩ
VB
+
-
ISHUNT
VR
RL
VGEN
Figure 1. Load-Transient Test Circuit
LM4040
Improved Precision Micropower Shunt Voltage
Reference with Multiple Reverse Breakdown Voltages
10 ______________________________________________________________________________________
VIN
VOUT
LM4040-5.0V
STARTUP CHARACTERISTICS
LM4040-13
0405020 3010 60 70 80 90
RESPONSE TIME (µs)
5V
0V
0V
4V
2V
RS = 16kΩ
SEE FIGURE 2
0.1k 10k1k 100k 1M
LM4040-2.5V
OUTPUT IMPEDANCE vs. FREQUENCY
LM4040-14
FREQUENCY (Hz)
IMPEDANCE (Ω)
1000
0.1
1
10
100
IR = 150µA
IR = 1mA
C1 = 1µF
C1 = 0
Typical Operating Characteristics (continued)
(IR= 100µA, SC70 package, TA= +25°C, unless otherwise noted.)
VIN
VOUT
LM4040-2.5V
STARTUP CHARACTERISTICS
LM4040-12
01620812424283236
RESPONSE TIME (µs)
5V
0V
0V
2V
1V
RS = 30kΩ
SEE FIGURE 2
110010 1k 10k
LM4040-5.0V
NOISE vs. FREQUENCY
LM4040-17
FREQUENCY (Hz)
10,000
100
1000
NOISE (nV/√Hz)
0.1k 10k1k 100k 1M
LM4040-5.0V
OUTPUT IMPEDANCE vs. FREQUENCY
LM4040-15
FREQUENCY (Hz)
IMPEDANCE (Ω)
100
0.1
1
10 IR = 150µA
IR = 1mA
C1 = 0
C1 = 1µF
RS
VIN
1Hz RATE
50%
DUTY CYCLE
VR
Figure 2. Startup Characteristics Test Circuit
LM4040
Improved Precision Micropower Shunt Voltage
Reference with Multiple Reverse Breakdown Voltages
______________________________________________________________________________________ 11
Detailed Description
The LM4040 shunt references use the bandgap princi-
ple to produce a stable, accurate voltage. The device
behaves similarly to an ideal zener diode; a fixed volt-
age is maintained across its output terminals when
biased with 60µA to 15mA of reverse current. The
LM4040 behaves similarly to a silicon diode when
biased with forward currents up 10mA.
Figure 3 shows a typical operating circuit. The LM4040
is ideal for providing a stable reference from a high-
voltage power supply.
Applications Information
The LM4040’s internal pass transistor is used to maintain a
constant output voltage (VSHUNT) by sinking the necessary
amount of current across a source resistor. The source
resistance (RS) is determined from the load current (ILOAD)
range, supply voltage (VS) variations, VSHUNT, and desired
quiescent current.
Choose the value of RSwhen VSis at a minimum and ILOAD
is at a maximum. Maintain a minimum ISHUNT of 60µA at all
times. The RSvalue should be large enough to keep
ISHUNT less than 15mA for proper regulation when VSis
maximum and ILOAD is at a minimum. To prevent damage
to the device, ISHUNT should never exceed 20mA.
Therefore, the value of RSis bounded by the following
equation:
[VS(MIN) - VR] / [60µA + ILOAD(MAX)] > RS>
[VS(MAX) - VR] / [20mA + ILOAD(MIN)]
Choosing a larger resistance minimizes the total power dis-
sipation in the circuit by reducing the shunt current
(PD(TOTAL) = VSISHUNT). Provide a safety margin to
incorporate the worst-case tolerance of the resistor used.
Ensure that the resistor’s power rating is adequate, using
the following general power equation:
PDR= ISHUNT (VS(MAX) - VSHUNT)
Output Capacitance
The LM4040 does not require an external capacitor for fre-
quency stability and is stable for any output capacitance.
Temperature Performance
The LM4040 typically exhibits an output voltage tem-
perature coefficient within ±15ppm/°C. The polarity of
the temperature coefficient may be different from one
device to another; some may have positive coefficients,
and others may have negative coefficients.
High Temperature Operation
The maximum junction temperature of the LM4040 is
+150°C. The maximum operating temperature for the
LM4040_E_ is +125°C. At a maximum load current of 15mA
and a maximum output voltage of 5V, the part will dissipate
75mW of power. The power dissipation limits of the 3-pin
SC70 call for a derating value of 2.17mW/°C above +70°C
and thus for 75mW of power dissipation, the part will self-
heat to 35.56°C above ambient temperature. If the ambient
temperature is +125°C, the part operates at 159.56°C,
thereby exceeding the maximum junction temperature
value of +150°C. For high-temperature operation, care must
be taken to ensure the combination of ambient temperature,
output power dissipation and package thermal resistance
does not conspire to raise the device temperature beyond
that listed in the
Absolute Maximum Ratings
. Either reduce
the output load current or the ambient temperature to keep
the part within the limits.
Figure 3. Typical Operating Circuit
LM4040
ILOAD
ISHUNT
RS
VS
VR
ISHUNT + ILOAD
Pin Description
PIN NAME FUNCTION
1 + Positive Terminal of the Shunt Reference
2−Negative Terminal of the Shunt Reference
3 N.C. No connection. Leave this pin unconnected or connected to pin 2.
LM4040
Improved Precision Micropower Shunt Voltage
Reference with Multiple Reverse Breakdown Voltages
12 ______________________________________________________________________________________
PART OUTPUT
VOLTAGE (V)
INITIAL
ACCURACY
(%)
TEMPCO
(ppm/°C) TEMP RANGE PIN-PACKAGE TOP
MARK
LM4040AIM3-2.1+T 2.048 0.1 100 -40°C to +85°C 3 SOT23 FZEF
LM4040AIX3-2.1+T 2.048 0.1 100 -40°C to +85°C 3 SC70 ABJ
LM4040BIM3-2.1+T 2.048 0.2 100 -40°C to +85°C 3 SOT23 FZEG
LM4040BIX3-2.1+T 2.048 0.2 100 -40°C to +85°C 3 SC70 ABK
LM4040CIM3-2.1+T 2.048 0.5 100 -40°C to +85°C 3 SOT23 FZEH
LM4040CIX3-2.1+T 2.048 0.5 100 -40°C to +85°C 3 SC70 ABL
LM4040DIM3-2.1+T 2.048 1.0 150 -40°C to +85°C 3 SOT23 FZEI
LM4040DIX3-2.1+T 2.048 1.0 150 -40°C to +85°C 3 SC70 ABM
LM4040AEM3-2.1+T 2.048 0.1 100 -40°C to +125°C 3 SOT23 FZNG
LM4040AEX3-2.1+T 2.048 0.1 100 -40°C to +125°C 3 SC70 ALF
LM4040BEM3-2.1-T 2.048 0.2 100 -40°C to +125°C 3 SOT23 FZNH
LM4040BEX3-2.1-T 2.048 0.2 100 -40°C to +125°C 3 SC70 ALG
LM4040CEM3-2.1-T 2.048 0.5 100 -40°C to +125°C 3 SOT23 FZNI
LM4040CEX3-2.1+T 2.048 0.5 100 -40°C to +125°C 3 SC70 ALH
LM4040DEM3-2.1+T 2.048 1.0 150 -40°C to +125°C 3 SOT23 FZNJ
LM4040DEX3-2.1+T 2.048 1.0 150 -40°C to +125°C 3 SC70 ALI
LM4040AIM3-2.5+T 2.500 0.1 100 -40°C to +85°C 3 SOT23 FZEJ
LM4040AIX3-2.5+T 2.500 0.1 100 -40°C to +85°C 3 SC70 ABN
LM4040BIM3-2.5+T 2.500 0.2 100 -40°C to +85°C 3 SOT23 FZEK
LM4040BIM3-2.5/V+T 2.500 0.2 100 -40°C to +125°C 3 SOT23 FZWL
LM4040BIX3-2.5+T 2.500 0.2 100 -40°C to +85°C 3 SC70 ABO
LM4040CIM3-2.5+T 2.500 0.5 100 -40°C to +85°C 3 SOT23 FZEL
LM4040CIX3-2.5+T 2.500 0.5 100 -40°C to +85°C 3 SC70 ABP
LM4040DIM3-2.5+T 2.500 1.0 150 -40°C to +85°C 3 SOT23 FZEM
LM4040DIX3-2.5+T 2.500 1.0 150 -40°C to +85°C 3 SC70 ABQ
LM4040AEM3-2.5+T 2.500 0.1 100 -40°C to +125°C 3 SOT23 FZNK
LM4040AEX3-2.5+T 2.500 0.1 100 -40°C to +125°C 3 SC70 ALJ
LM4040BEM3-2.5+T 2.500 0.2 100 -40°C to +125°C 3 SOT23 FZNL
LM4040BEX3-2.5+T 2.500 0.2 100 -40°C to +125°C 3 SC70 ALK
LM4040CEM3-2.5+T 2.500 0.5 100 -40°C to +125°C 3 SOT23 FZNM
LM4040CEM3-2.5/V+T 2.500 0.5 100 -40°C to +125°C 3 SOT23 FZVZ
LM4040CEX3-2.5+T 2.500 0.5 100 -40°C to +125°C 3 SC70 ALL
LM4040DEM3-2.5+T 2.500 1.0 150 -40°C to +125°C 3 SOT23 FZNN
LM4040DEX3-2.5+T 2.500 1.0 150 -40°C to +125°C 3 SC70 ALM
Ordering Information
+
Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
LM4040
Improved Precision Micropower Shunt Voltage
Reference with Multiple Reverse Breakdown Voltages
______________________________________________________________________________________ 13
PART OUTPUT
VOLTAGE (V)
INITIAL
ACCURACY
(%)
TEMPCO
(ppm/°C) TEMP RANGE PIN-PACKAGE TOP
MARK
LM4040AIM3-3.0+T 3.000 0.1 100 -40°C to +85°C 3 SOT23 FZEN
LM4040AIX3-3.0+T 3.000 0.1 100 -40°C to +85°C 3 SC70 ABR
LM4040BIM3-3.0+T 3.000 0.2 100 -40°C to +85°C 3 SOT23 FZEO
LM4040BIX3-3.0+T 3.000 0.2 100 -40°C to +85°C 3 SC70 ABS
LM4040CIM3-3.0+T 3.000 0.5 100 -40°C to +85°C 3 SOT23 FZEP
LM4040CIX3-3.0+T 3.000 0.5 100 -40°C to +85°C 3 SC70 ABT
LM4040DIM3-3.0+T 3.000 1.0 150 -40°C to +85°C 3 SOT23 FZEQ
LM4040DIX3-3.0+T 3.000 1.0 150 -40°C to +85°C 3 SC70 ABU
LM4040AEM3-3.0+T 3.000 0.1 100 -40°C to +125°C 3 SOT23 FZNO
LM4040AEX3-3.0+T 3.000 0.1 100 -40°C to +125°C 3 SC70 ALN
LM4040BEM3-3.0+T 3.000 0.2 100 -40°C to +125°C 3 SOT23 FZNP
LM4040BEX3-3.0+T 3.000 0.2 100 -40°C to +125°C 3 SC70 ALO
LM4040CEX3-3.0+T 3.000 0.5 100 -40°C to +125°C 3 SC70 ALP
LM4040DEM3-3.0+T 3.000 1.0 150 -40°C to +125°C 3 SOT23 FZNR
LM4040DEX3-3.0+T 3.000 1.0 150 -40°C to +125°C 3 SC70 ALQ
LM4040AEX3-3.3+T 3.300 0.1 100 -40°C to +125°C 3 SC70 ANY
LM4040BEX3-3.3+T 3.300 0.2 100 -40°C to +125°C 3 SC70 ANZ
LM4040CEX3-3.3+T 3.300 0.5 100 -40°C to +125°C 3 SC70 AOA
LM4040DEX3-3.3+T 3.300 1.0 150 -40°C to +125°C 3 SC70 AOB
LM4040AIM3-4.1+T 4.096 0.1 100 -40°C to +85°C 3 SOT23 FZER
LM4040AIX3-4.1+T 4.096 0.1 100 -40°C to +85°C 3 SC70 ABV
LM4040BIM3-4.1+T 4.096 0.2 100 -40°C to +85°C 3 SOT23 FZES
LM4040BIX3-4.1+T 4.096 0.2 100 -40°C to +85°C 3 SC70 ABW
LM4040CIM3-4.1+T 4.096 0.5 100 -40°C to +85°C 3 SOT23 FZET
LM4040CIX3-4.1+T 4.096 0.5 100 -40°C to +85°C 3 SC70 ABX
LM4040DIM3-4.1+T 4.096 1.0 150 -40°C to +85°C 3 SOT23 FZEU
LM4040DIX3-4.1+T 4.096 1.0 150 -40°C to +85°C 3 SC70 ABY
LM4040AEM3-4.1+T 4.096 0.1 100 -40°C to +125°C 3 SOT23 FZNS
LM4040AEX3-4.1+T 4.096 0.1 100 -40°C to +125°C 3 SC70 ALR
LM4040BEM3-4.1+T 4.096 0.2 100 -40°C to +125°C 3 SOT23 FZNT
LM4040BEX3-4.1+T 4.096 0.2 100 -40°C to +125°C 3 SC70 ALS
LM4040CEM3-4.1+T 4.096 0.5 100 -40°C to +125°C 3 SOT23 FZNU
Ordering Information (continued)
+
Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
LM4040
Improved Precision Micropower Shunt Voltage
Reference with Multiple Reverse Breakdown Voltages
14 ______________________________________________________________________________________
PART OUTPUT
VOLTAGE (V)
INITIAL
ACCURACY
(%)
TEMPCO
(ppm/°C) TEMP RANGE PIN-PACKAGE TOP
MARK
LM4040CEX3-4.1+T 4.096 0.5 100 -40°C to +125°C 3 SC70 ALT
LM4040DEM3-4.1+T 4.096 1.0 150 -40°C to +125°C 3 SOT23 FZNV
LM4040DEM3-4.1/V+T 4.096 1.0 150 -40°C to +125°C 3 SOT23 FZWA
LM4040DEX3-4.1+T 4.096 1.0 150 -40°C to +125°C 3 SC70 ALU
LM4040AIM3-5.0+T 5.000 0.1 100 -40°C to +85°C 3 SOT23 FZEV
LM4040AIX3-5.0+T 5.000 0.1 100 -40°C to +85°C 3 SC70 ABZ
LM4040BIM3-5.0+T 5.000 0.2 100 -40°C to +85°C 3 SOT23 FZEW
LM4040BIX3-5.0+T 5.000 0.2 100 -40°C to +85°C 3 SC70 ACA
LM4040CIM3-5.0+T 5.000 0.5 100 -40°C to +85°C 3 SOT23 FZEX
LM4040CIX3-5.0+T 5.000 0.5 100 -40°C to +85°C 3 SC70 ACB
LM4040DIM3-5.0+T 5.000 1.0 150 -40°C to +85°C 3 SOT23 FZEY
LM4040DIX3-5.0+T 5.000 1.0 150 -40°C to +85°C 3 SC70 ACC
LM4040AEM3-5.0+T 5.000 0.1 100 -40°C to +125°C 3 SOT23 FZNW
LM4040AEM3-5.0/V+T 5.000 0.1 100 -40°C to +125°C 3 SOT23 FZWB
LM4040AEX3-5.0+T 5.000 0.1 100 -40°C to +125°C 3 SC70 ALV
LM4040BEM3-5.0+T 5.000 0.2 100 -40°C to +125°C 3 SOT23 FZNX
LM4040BEX3-5.0+T 5.000 0.2 100 -40°C to +125°C 3 SC70 ALW
LM4040CEM3-5.0+T 5.000 0.5 100 -40°C to +125°C 3 SOT23 FZNY
LM4040CEM3-5.0/V+T 5.000 0.5 100 -40°C to +125°C 3 SOT23 +FZWC
LM4040CEX3-5.0+T 5.000 0.5 100 -40°C to +125°C 3 SC70 ALX
LM4040DEM3-5.0+T 5.000 1.0 150 -40°C to +125°C 3 SOT23 FZNZ
LM4040DEX3-5.0+T 5.000 1.0 150 -40°C to +125°C 3 SC70 ALY
Ordering Information (continued)
Chip Information
PROCESS: BiCMOS
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maxim-ic.com/packages. Note that a
“+”, “#”, or “-” in the package code indicates RoHS status only.
Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
PACKAGE
TYPE
PACKAGE
CODE OUTLINE NO. LAND
PATTERN NO.
3 SOT23 U3+1 21-0051 90-0179
3 SC70 X3+2 21-0075 90-0208
+
Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in
the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
15
____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2011 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
LM4040
Improved Precision Micropower Shunt Voltage
Reference with Multiple Reverse Breakdown Voltages
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 8/00 Initial release —
5 7/05 Updated Electrical Characteristics. 2–7
6 4/11 Updated Selector Guide, Absolute Maximum Ratings, and Ordering
Information.1, 2, 12, 13, 14
7 11/11 Add /V+ automotive-qualified identification to the Selector Guide and
Ordering Information.1, 12