19-1704; Rev 4; 7/05
Improved Precision Micropower
Shunt Voltage Reference
General Description
The LM4041 is a precision two-terminal shunt mode,
bandgap voltage reference with a fixed reverse break-
down voltage of 1.225V. Ideal for space-critical appli-
cations, the LM4041 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 LM4041 has a 60µA to 12mA shunt
current capability with low dynamic impedance, ensur-
ing stable reverse-breakdown voltage accuracy over a
wide range of operating temperatures and currents.
The LM4041 does not require an external stabilizing
capacitor while ensuring stability with any capacitive
load.
The LM4041 is guaranteed over the temperature range
-40°C to +125°C.
Features
♦
Ultra-Small 3-Pin SC70 Package
♦
0.1% (max) Initial Accuracy
♦
100ppm/°C (max) Temperature Coefficient
Guaranteed over -40°C to +125°C Temperature
Range
♦
Wide Operating Current Range: 60µA to 12mA
♦
Low 20µV
RMS
Output Noise (10Hz to 10kHz)
♦
1.225V Fixed Reverse Breakdown Voltage
♦
No Output Capacitors Required
♦
Tolerates Capacitive Loads
LM4041
Ordering Information
PART
LM4041AIX3-1.2-T
LM4041AIM3-1.2-T
LM4041AEX3-1.2-T
LM4041AEM3-1.2-T
LM4041BIX3-1.2-T
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +125°C
-40°C to +125°C
-40°C to +85°C
-40°C to +85°C
-40°C to +125°C
-40°C to +125°C
-40°C to +85°C
-40°C to +85°C
-40°C to +125°C
-40°C to +125°C
-40°C to +85°C
-40°C to +85°C
-40°C to +125°C
-40°C to +125°C
PIN-
TOP
PACKAGE MARK
3 SC70-3
3 SOT23-3
3 SC70-3
3 SOT23-3
3 SC70-3
3 SOT23-3
3 SC70-3
3 SOT23-3
3 SC70-3
3 SOT23-3
3 SC70-3
3 SOT23-3
3 SC70-3
3 SOT23-3
3 SC70-3
3 SOT23-3
ABF
FZEB
ALB
FZNC
ABG
FZEC
ALC
FZND
ABH
FZED
ALD
FZNE
ABI
FZEE
ALE
FZNF
________________________Applications
Portable, Battery-Powered Equipment
Notebook Computers
Cell Phones
Industrial Process Controls
LM4041BIM3-1.2-T
LM4041BEX3-1.2-T
LM4041BEM3-1.2-T
LM4041CIX3-1.2-T
LM4041CIM3-1.2-T
LM4041CEX3-1.2-T
LM4041CEM3-1.2-T
LM4041DIX3-1.2-T
LM4041DIM3-1.2-T
LM4041DEX3-1.2-T
Pin Configuration
TOP VIEW
LM4041DEM3-1.2-T
*See
Selector Guide for a listing of LM4041 Output Voltage,
Initial Accuracy, and Temperature Coefficient specifications.
+
1
Selector Guide
LM4041
3
N.C.*
PART
LM4041A___-1.2-T
-
2
INITIAL
ACCURACY
(%)
0.1
0.2
0.5
1.0
OUTPUT
VOLTAGE
(V)
1.225
1.225
1.225
1.225
TEMPCO
(ppm/°C)
100
100
100
150
SC70-3/SOT23-3
*PIN 3 MUST BE LEFT FLOATING OR CONNECTED TO PIN 2.
LM4041B___-1.2-T
LM4041C___-1.2-T
LM4041D___-1.2-T
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Improved Precision Micropower
Shunt Voltage Reference
LM4041
ABSOLUTE MAXIMUM RATINGS
Reverse Current (cathode to anode) ..................................20mA
Forward Current (anode to cathode) ..................................10mA
Continuous Power Dissipation (T
A
= +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
LM4041_I_ _ _..................................................-40°C to +85°C
LM4041_E_ _ _ ..............................................-40°C to +125°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature ......................................................+150°C
Lead Temperature (soldering, 10s) ................................+300° C
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.
ELECTRICAL CHARACTERISTICS
(I
R
= 100µA, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
LM4041A (0.1%)
Reverse Breakdown Voltage
V
R
T
A
= +25°C
LM4041B (0.2%)
LM4041C (0.5%)
LM4041D (1.0%)
LM4041A (0.1%)
Reverse Breakdown Voltage
Tolerance (Note 2)
∆V
R
LM4041B (0.2%)
LM4041C (0.5%)
LM4041D (1.0%)
Minimum Operating Current
I
RMIN
I
R
= 10mA
Average Reverse Voltage
Temperature Coefficient
(Notes 2 and 3)
∆V
R
/∆T
I
R
= 1mA
I
R
= 100µA
Reverse Breakdown Voltage
Change with Operating
Current Change
Reverse Dynamic
Impedance (Note 3)
I
RMIN
≤
I
R
≤
1mA
∆V
R
/∆I
R
1mA
≤
I
R
≤
12mA
Z
R
I
R
= 1mA, f = 120Hz,
I
AC
= 0.1I
R
LM4041A/B/C
LM4041D
LM4041A/B/C
LM4041D
LM4041A/B/C
LM4041D
LM4041A/B/C
LM4041D
LM4041A/B/C
LM4041D
MIN
1.2238
1.2226
1.2189
1.2128
TYP
1.2250
1.2250
1.2250
1.2250
±1.2
±2.4
±6.0
±12
45
45
±20
±15
±15
±15
0.7
0.7
2.5
2.5
0.5
0.5
1.5
2.0
8.0
10.0
1.5
2.0
Ω
mV
±100
±150
ppm/°C
MAX
1.2262
1.2275
1.2311
1.2373
±9.2
±10.4
±14
±24
60
65
µA
mV
V
UNITS
2
_______________________________________________________________________________________
Improved Precision Micropower
Shunt Voltage Reference
ELECTRICAL CHARACTERISTICS (continued)
(I
R
= 100µA, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
Wideband Noise
Reverse Breakdown Voltage
Long-Term Stability
SYMBOL
e
N
∆V
R
CONDITIONS
I
R
= 100µA, 10Hz
≤
f
≤
10kHz
T = 1000h, I
R
= 100µA
MIN
TYP
20
120
MAX
UNITS
µV
RMS
ppm
LM4041
Note 1:
All devices are 100% production tested at +25°C and are guaranteed by design for T
A
= T
MIN
to T
MAX
, as specified.
Note 2:
The overtemperature limit for Reverse Breakdown Voltage Tolerance is defined as the room-temperature Reverse
Breakdown Voltage Tolerance ±[(∆V
R
/
∆T)(max∆T)(V
R
)], where
∆V
R
/
∆T
is the V
R
temperature coefficient, max∆T is the
maximum difference in temperature from the reference point of +25°C to T
MIN
or T
MAX
, and V
R
is the reverse breakdown
voltage. 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 overtemperature 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 LM4041-1.2 has an overtemperature reverse breakdown voltage tolerance of ±2.5V
x 0.75% = ±19mV.
Note 3:
Guaranteed by design.
Typical Operating Characteristics
(I
R
= 100µA, SC70-3 package, T
A
= +25°C, unless otherwise noted.)
REVERSE CHARACTERISTICS AND
MINIMUM OPERATING CURRENT
LM4041-01
TEMPERATURE DRIFT
LM4041 toc02
REVERSE VOLTAGE vs. CURRENT
LM4041 toc03
100
1
REFERENCE VOLTAGE CHANGE (mV)
6
REVERSE VOLTAGE CHANGE (mV)
5
4
3
2
T
A
= -40°C
1
0
T
A
= +85°C
T
A
= +125°C
T
A
= +25°C
80
REVERSE CURRENT (µA)
0
60
-1
40
20
-2
0
0
0.4
0.8
1.2
1.6
2.0
REVERSE VOLTAGE (V)
-3
-50
-25
0
25
50
75
100
125
TEMPERATURE (°C)
0
5
10
15
20
SOURCE CURRENT (mA)
_______________________________________________________________________________________
3
Improved Precision Micropower
Shunt Voltage Reference
LM4041
Typical Operating Characteristics (continued)
(I
R
= 100µA, SC70-3 package, T
A
= +25°C, unless otherwise noted.)
LOAD-TRANSIENT RESPONSE
LM4041-04
LOAD-TRANSIENT RESPONSE
LM4041-05
LOAD-TRANSIENT RESPONSE
LM4041-06
V
GEN
V
GEN
2V/div
2V/div
V
GEN
2V/div
V
R
(AC-COUPLED)
V
R
(AC-COUPLED)
2mV/div
I
SHUNT
= 100µA
±
25µA,
R
L
= 100kΩ
SEE FIGURE 1
10µs/div
I
SHUNT
= 1mA
±
250µA,
R
L
= 10kΩ
SEE FIGURE 1
10µs/div
V
R
2mV/div
2mV/div
I
SHUNT
= 10mA
±
2.5mA,
R
L
= 1kΩ
SEE FIGURE 1
10µs/div
STARTUP CHARACTERISTICS
LM4041-07
OUTPUT IMPEDANCE vs. FREQUENCY
LM4041-08
NOISE vs. FREQUENCY
I
R
= 200µA
LM4041-09
5V
V
IN
OV
R
S
= 30kΩ
SEE FIGURE 2
1000
C
1
= 0
100
IMPEDANCE (Ω)
10,000
NOISE (nV/√Hz)
C
1
= 1µF
I
R
= 1mA
1.5V
1.0V
V
OUT
O.5V
0V
1000
10
I
R
= 150µA
1
0.1
0
4
8
12
16
100
1k
RESPONSE TIME (µs)
100
100k
1M
10
100
1k
10k
FREQUENCY (Hz)
10k
FREQUENCY (Hz)
I
SHUNT
1kΩ
R
L
V
R
V
GEN
V
IN
1Hz RATE
R
S
30kΩ
V
B
+
-
V
R
Figure 1. Load-Transient Test Circuit
Figure 2. Startup Characteristics Test Circuit
4
_______________________________________________________________________________________
Improved Precision Micropower
Shunt Voltage Reference
Pin Description
PIN
1
2
3
NAME
+
−
N.C.
Positive Terminal of the Shunt Reference
Negative Terminal of the Shunt Reference
Leave this pin unconnected, or connect to pin 2.
FUNCTION
LM4041
Detailed Description
The LM4041 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 of +1.225V is maintained across its output termi-
nals when biased with 60µA to 12mA of reverse
current. The LM4041 behaves similarly to a silicon
diode when biased with forward currents up 10mA.
Figure 3 shows a typical operating circuit. The LM4041
is ideal for providing a stable reference from a high-
voltage power supply.
V
S
I
SHUNT
+ I
LOAD
I
LOAD
V
R
I
SHUNT
R
S
Applications Information
The LM4041’s internal pass transistor is used to main-
tain a constant output voltage (V
SHUNT
) by sinking the
necessary amount of current across a source resistor.
The source resistance (R
S
) is determined from the load
current (I
LOAD
) range, supply voltage (V
S
) variations,
V
SHUNT
, and desired quiescent current.
Choose the value of R
S
when V
S
is at a minimum and
I
LOAD
is at a maximum. Maintain a minimum I
SHUNT
of
60µA at all times. The R
S
value should be large enough
to keep I
SHUNT
less than 12mA for proper regulation
when V
S
is maximum and I
LOAD
is at a minimum. To
prevent damage to the device, I
SHUNT
should never
exceed 20mA.
Therefore, the value of R
S
is bounded by the following
equation:
[V
S(MIN)
- V
R
] / [60µA + I
LOAD(MAX)
] > R
S
>
[V
S(MAX)
- V
R
] / [20mA + I
LOAD(MIN)
]
Choosing a larger resistance minimizes the total power
dissipation in the circuit by reducing the shunt current
(P
D(TOTAL)
= V
S
✕
I
SHUNT
). Provide a safety margin to
incorporate the worst-case tolerance of the resistor
LM4041
Figure 3. Typical Operating Circuit
used. Ensure that the resistor’s power rating is ade-
quate, using the following general power equation:
P
R
= I
SHUNT
✕
(V
S(MAX)
- V
R
)
Output Capacitance
The LM4041 does not require an external capacitor for
frequency stability and is stable for any output capaci-
tance.
Temperature Performance
The LM4041 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.
_______________________________________________________________________________________
5
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