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.
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 60A 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
-40C to +125C.
________________________Applications
Portable, Battery-Powered Equipment
Notebook Computers
Cell Phones
Industrial Process Controls
Features
o Ultra-Small 3-Pin SC70 Package
o 0.1% (max) Initial Accuracy
o 100ppm/C (max) Temperature Coefficient
Guaranteed over -40C to +125C Temperature
Range
o Wide Operating Current Range: 60A to 12mA
o Low 20V
RMS
Output Noise (10Hz to 10kHz)
o 1.225V Fixed Reverse Breakdown Voltage
o No Output Capacitors Required
o Tolerates Capacitive Loads
LM4041
Improved Precision Micropower
Shunt Voltage Reference
________________________________________________________________ Maxim Integrated Products
1
-
1
3
N.C.*
+
LM4041
SC70-3/SOT23-3
TOP VIEW
2
*PIN 3 MUST BE LEFT FLOATING OR CONNECTED TO PIN 2.
PART
INITIAL
ACCURACY
(%)
OUTPUT
VOLTAGE
(V)
TEMPCO
(ppm/C)
LM4041A___-1.2-T
0.1
1.225
100
LM4041B___-1.2-T
0.2
1.225
100
LM4041C___-1.2-T
0.5
1.225
100
LM4041D___-1.2-T
1.0
1.225
150
Pin Configuration
Selector Guide
19-1704; Rev 2; 5/03
Ordering Information
PART
TEMP RANGE
PIN-
PACKAGE
TOP
MARK
LM4041AIX3-1.2-T
-40C to +85C
3 SC70-3
ABF
LM4041AIM3-1.2-T
-40C to +85C
3 SOT23-3
FZEB
LM4041AEX3-1.2-T
-40C to +125C
3 SC70-3
ALB
LM4041AEM3-1.2-T
-40C to +125C
3 SOT23-3
FZNC
LM4041BIX3-1.2-T
-40C to +85C
3 SC70-3
ABG
LM4041BIM3-1.2-T
-40C to +85C
3 SOT23-3
FZEC
LM4041BEX3-1.2-T
-40C to +125C
3 SC70-3
ALC
LM4041BEM3-1.2-T
-40C to +125C
3 SOT23-3
FZND
LM4041CIX3-1.2-T
-40C to +85C
3 SC70-3
ABH
LM4041CIM3-1.2-T
-40C to +85C
3 SOT23-3
FZED
LM4041CEX3-1.2-T
-40C to +125C
3 SC70-3
ALD
LM4041CEM3-1.2-T
-40C to +125C
3 SOT23-3
FZNE
LM4041DIX3-1.2-T
-40C to +85C
3 SC70-3
ABI
LM4041DIM3-1.2-T
-40C to +85C
3 SOT23-3
FZEE
LM4041DEX3-1.2-T
-40C to +125C
3 SC70-3
ALE
LM4041DEM3-1.2-T
-40C to +125C
3 SOT23-3
FZNF
*See Selector Guide for a listing of LM4041 Output Voltage,
Initial Accuracy, and Temperature Coefficient specifications.
LM4041
Improved Precision Micropower
Shunt Voltage Reference
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(I
R
= 100A, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25C.) (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
ESD per Method 3015.7
Human Body Model .......................................................2000V
Machine Model.................................................................200V
Continuous Power Dissipation (T
A
= +70C)
3-Pin SC70 (derate 2.17mW/C above +70C) ............174mW
3-Pin SOT23 (derate 4.01mW/C above +70C)..........320mW
Operating Temperature Range
LM4041_I_ _ _..................................................-40C to +85C
LM4041_E_ _ _ ..............................................-40C to +125C
Storage Temperature Range .............................-65C to +150C
Junction Temperature ......................................................+150C
Lead Temperature (soldering, 10s) ................................+300 C
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
LM4041A (0.1%)
1.2238
1.2250
1.2262
LM4041B (0.2%)
1.2226
1.2250
1.2275
LM4041C (0.5%)
1.2189
1.2250
1.2311
Reverse Breakdown Voltage
V
R
T
A
= +25C
LM4041D (1.0%)
1.2128
1.2250
1.2373
V
LM4041A (0.1%)
1.2
9.2
LM4041B (0.2%)
2.4
10.4
LM4041C (0.5%)
6.0
14
Reverse Breakdown Voltage
Tolerance (Note 2)
V
R
LM4041D (1.0%)
12
24
mV
LM4041A/B/C
45
60
Minimum Operating Current
I
RMIN
LM4041D
45
65
A
I
R
= 10mA
20
LM4041A/B/C
15
100
I
R
= 1mA
LM4041D
15
150
Average Reverse Voltage
Temperature Coefficient
(Note 2)
V
R
/
T
I
R
= 100
A
15
ppm/
C
LM4041A/B/C
0.7
1.5
I
RMIN
I
R
1mA
LM4041D
0.7
2.0
LM4041A/B/C
2.5
8.0
Reverse Breakdown Voltage
Change with Operating
Current Change
V
R
/
I
R
1mA
I
R
12mA
LM4041D
2.5
10.0
mV
LM4041A/B/C
0.5
1.5
Reverse Dynamic
Impedance (Note 3)
Z
R
I
R
= 1mA, f = 120Hz,
I
AC
= 0.1I
R
LM4041D
0.5
2.0
LM4041
Improved Precision Micropower
Shunt Voltage Reference
_______________________________________________________________________________________
3
ELECTRICAL CHARACTERISTICS (continued)
(I
R
= 100A, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25C.) (Note 1)
Note 1: All devices are 100% production tested at +25C 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)(maxT)(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 +25C 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 = +65C is
shown below:
A grade: 0.75% = 0.1% 100ppm/C
65C
B grade: 0.85% = 0.2% 100ppm/C
65C
C grade: 1.15% = 0.5% 100ppm/C
65C
D grade: 1.98% = 1.0% 150ppm/C
65C
The total overtemperature tolerance for the different grades in the extended temperature range where max
T = +100C is
shown below:
A grade: 1.1% = 0.1% 100ppm/C
100C
B grade: 1.2% = 0.2% 100ppm/C
100C
C grade: 1.5% = 0.5% 100ppm/C
100C
D grade: 2.5% = 1.0% 150ppm/C
100C
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.
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Wideband Noise
e
N
I
R
= 100
A, 10Hz f 10kHz
20
V
RMS
Reverse Breakdown Voltage
Long-Term Stability
V
R
T = 1000h, I
R
= 100
A
120
ppm
TEMPERATURE DRIFT
LM4041 toc02
TEMPERATURE (
C)
REFERENCE VOLTAGE CHANGE (mV)
100
75
50
25
0
-25
-2
-1
0
1
-3
-50
125
REVERSE VOLTAGE vs. CURRENT
LM4041 toc03
SOURCE CURRENT (mA)
REVERSE VOLTAGE CHANGE (mV)
15
10
5
1
2
3
4
5
6
0
0
20
T
A
= +25
C
T
A
= -40
C
T
A
= +125
C
T
A
= +85
C
Typical Operating Characteristics
(I
R
= 100A, SC70-3 package, T
A
= +25C, unless otherwise noted.)
0
20
60
40
80
100
0
0.8
0.4
1.2
1.6
2.0
REVERSE CHARACTERISTICS AND
MINIMUM OPERATING CURRENT
LM4041-01
REVERSE VOLTAGE (V)
REVERSE CURRENT (A)
LM4041
Improved Precision Micropower
Shunt Voltage Reference
4
_______________________________________________________________________________________
100
10k
1k
100k
1M
OUTPUT IMPEDANCE vs. FREQUENCY
LM4041-08
FREQUENCY (Hz)
IMPEDANCE (
)
1000
0.1
1
10
100
C
1
= 0
I
R
=
C
1
= 1
F
I
R
= 1mA
150
A
10,000
100
10
1k
10k
1000
FREQUENCY (Hz)
100
NOISE vs. FREQUENCY
LM4041-09
I
R
= 200
A
NOISE (nV/
Hz)
R
S
= 30k
SEE FIGURE 2
0
8
4
12
16
STARTUP CHARACTERISTICS
LM4041-07
RESPONSE TIME (
s)
5V
V
IN
OV
0V
1.5V
1.0V
V
OUT
O.5V
V
GEN
V
R
(AC-COUPLED)
2V/div
2mV/div
LOAD-TRANSIENT RESPONSE
LM4041-05
10
s/div
I
SHUNT
= 1mA
250A,
R
L
= 10k
SEE FIGURE 1
V
GEN
V
R
2V/div
2mV/div
LOAD-TRANSIENT RESPONSE
LM4041-06
10
s/div
I
SHUNT
= 10mA
2.5mA,
R
L
= 1k
SEE FIGURE 1
V
GEN
V
R
(AC-COUPLED)
2V/div
2mV/div
LOAD-TRANSIENT RESPONSE
LM4041-04
10
s/div
I
SHUNT
= 100
A 25A,
R
L
= 100k
SEE FIGURE 1
Typical Operating Characteristics (continued)
(I
R
= 100A, SC70-3 package, T
A
= +25C, unless otherwise noted.)
R
S
30k
V
IN
1Hz RATE
V
R
Figure 2. Startup Characteristics Test Circuit
1k
V
B
+
-
I
SHUNT
V
R
R
L
V
GEN
Figure 1. Load-Transient Test Circuit
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 60A 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.
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
60A 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
] / [60A + 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
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.
LM4041
Improved Precision Micropower
Shunt Voltage Reference
_______________________________________________________________________________________
5
Pin Description
PIN
NAME
FUNCTION
1
+
Positive Terminal of the Shunt Reference
2
-
Negative Terminal of the Shunt Reference
3
N.C.
Leave this pin unconnected, or connect to pin 2.
Figure 3. Typical Operating Circuit
LM4041
I
LOAD
I
SHUNT
R
S
V
S
V
R
I
SHUNT
+ I
LOAD
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