LM4125
Precision Micropower Low Dropout Voltage Reference
General Description
The LM4125 is a precision low power low dropout bandgap
voltage reference with up to 5 mA output current source and
sink capability.
This series reference operates with input voltages as low as
2V and up to 6V consuming 160 A (Typ.) supply current. In
power down mode, device current drops to less than 2 A.
The LM4125 comes in two grades (A and Standard) and
three voltage options for greater flexibility. The best grade
devices (A) have an initial accuracy of 0.2%, while the stan-
dard have an initial accuracy of 0.5%, both with a tempco of
50ppm/C guaranteed from -40C to +125C.
The very low dropout voltage, low supply current and power-
down capability of the LM4125 makes this product an ideal
choice for battery powered and portable applications.
The device performance is guaranteed over the industrial
temperature range (-40C to +85C), while certain specs are
guaranteed over the extended temperature range (-40C to
+125C). Please contact National for full specifications over
the extended temperature range. The LM4125 is available in
a standard 5-pin SOT-23 package.
Features
n
Small SOT23-5 package
n
Low dropout voltage:
120 mV Typ
@
1 mA
n
High output voltage accuracy:
0.2%
n
Source and Sink current output:
5 mA
n
Supply current:
160 A Typ.
n
Low Temperature Coefficient:
50 ppm/C
n
Fixed output voltages:
2.048, 2.5,and 4.096
n
Industrial temperature Range:
-40C to +85C
n
(For extended temperature range, -40C to 125C,
contact National Semiconductor)
Applications
n
Portable, battery powered equipment
n
Instrumentation and process control
n
Automotive & Industrial
n
Test equipment
n
Data acquisition systems
n
Precision regulators
n
Battery chargers
n
Base stations
n
Communications
n
Medical equipment
Connection Diagram
20069802
Refer to the Ordering Information Table in this Data Sheet for Specific Part Number
SOT23-5 Surface Mount Package
November 2003
LM4125
Precision
Micropower
Low
Dropout
V
oltage
Reference
2003 National Semiconductor Corporation
DS200698
www.national.com
Ordering Information
Industrial Temperature Range (-40C to + 85C)
Initial Output Voltage Accuracy at 25C
And Temperature Coefficient
LM4125 Supplied as
1000 Units, Tape and
Reel
LM4125 Supplied as
3000 Units, Tape and
Reel
Top
Marking
0.2%, 50 ppm/C max (A grade)
LM4125AIM5-2.0
LM4125AIM5X-2.0
R80A
LM4125AIM5-2.5
LM4125AIM5X-2.5
R81A
LM4125AIM5-4.1
LM4125AIM5X-4.1
R82A
0.5%, 50 ppm/C max
LM4125IM5-2.0
LM4125IM5X-2.0
R80B
LM4125IM5-2.5
LM4125IM5X-2.5
R81B
LM4125IM5-4.1
LM4125IM5X-4.1
R82B
SOT-23 Package Marking Information
Only four fields of marking are possible on the SOT-23's small surface. This
table gives the meaning of the four fields.
Field Information
First Field:
R = Reference
Second and third Field:
80 = 2.048V Voltage Option
81 = 2.500V Voltage Option
82 = 4.096V Voltage Option
Fourth Field:
A-B = Initial Reference Voltage Tolerance
A =
0.2%
B =
0.5%
LM4125
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2
Absolute Maximum Ratings
(Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Maximum Voltage on input or
enable pins
-0.3V to 8V
Output Short-Circuit Duration
Indefinite
Power Dissipation (T
A
= 25C) (Note 2):
MA05B package -
JA
280C/W
Power Dissipation
350 mW
ESD Susceptibility (Note 3)
Human Body Model
Machine Model
2 kV
200V
Lead Temperature:
Soldering, (10 sec.)
+260C
Vapor Phase (60 sec.)
+215C
Infrared (15 sec.)
+220C
Operating Range
(Note 1)
Storage Temperature
Range
-65C to +150C
Ambient Temperature
Range
-40C to +85C
Junction Temperature
Range
-40C to +125C
Electrical Characteristics
LM4125-2.048V and 2.5V
Unless otherwise specified V
IN
= 3.3V, I
LOAD
= 0, C
OUT
= 0.01F, T
A
= T
j
= 25C.
Limits with standard typeface are for T
j
= 25C, and limits in boldface type apply over the -40C
T
A
+85C temperature
range.
Symbol
Parameter
Conditions
Min
(Note 5)
Typ
(Note 4)
Max
(Note 5)
Units
V
OUT
Output Voltage Initial
Accuracy
LM4125A-2.048
LM4125A-2.500
0.2
%
LM4125-2.048
LM4125-2.500
0.5
%
TCV
OUT
/C
Temperature
Coefficient
-40C
T
A
+125C
14
50
ppm/c
V
OUT
/
V
IN
Line Regulation
3.3V
V
IN
6V
0.0007
0.008
0.01
%/V
V
OUT
/
I
LOAD
Load Regulation
0 mA
I
LOAD
1 mA
0.03
0.08
0.17
%/mA
1 mA
I
LOAD
5 mA
0.01
0.04
0.1
-1 mA
I
LOAD
0 mA
0.04
0.12
-5 mA
I
LOAD
-1 mA
0.01
V
IN
-V
OUT
Dropout Voltage
(Note 6)
I
LOAD
= 0 mA
45
65
100
mV
I
LOAD
= +1 mA
120
150
200
I
LOAD
= +5 mA
180
210
300
V
N
Output Noise Voltage
(Note 8)
0.1 Hz to 10 Hz
20
V
PP
10 Hz to 10 kHz
36
V
PP
I
S
Supply Current
160
257
290
A
I
SC
Short Circuit Current
V
IN
= 3.3V, V
OUT
= 0
15
mA
6
30
V
IN
= 6V, V
OUT
= 0
17
6
30
Hyst
Thermal Hysteresis
(Note 7)
-40C
T
A
125C
0.5
mV/V
LM4125
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3
Electrical Characteristics
LM4125-2.048V and 2.5V
Unless otherwise specified V
IN
= 3.3V, I
LOAD
= 0, C
OUT
= 0.01F, T
A
= T
j
= 25C.
Limits with standard typeface are for T
j
= 25C, and limits in boldface type apply over the -40C
T
A
+85C temperature
range. (Continued)
Symbol
Parameter
Conditions
Min
(Note 5)
Typ
(Note 4)
Max
(Note 5)
Units
V
OUT
Long Term Stability
(Note 9)
1000 hrs.
@
25C
100
ppm
Electrical Characteristics
LM4125-4.096V
Unless otherwise specified V
IN
= 5V, I
LOAD
= 0, C
OUT
= 0.01F, T
A
= T
j
= 25C. Limits with standard typeface are for T
j
=
25C, and limits in boldface type apply over the -40C
T
A
+85C temperature range.
Symbol
Parameter
Conditions
Min (Note 5)
Typ (Note
4)
Max (Note
5)
Units
V
OUT
Output Voltage Initial
Accuracy
LM4125A-4.096
0.2
%
LM4125-4.096
0.5
%
TCV
OUT
/C
Temperature
Coefficient
-40C
T
A
+125C
14
50
ppm/c
V
OUT
/
V
IN
Line Regulation
5V
V
IN
6V
0.0007
0.008
0.01
%/V
V
OUT
/
I
LOAD
Load Regulation
0 mA
I
LOAD
1 mA
0.03
0.08
0.17
%/mA
1 mA
I
LOAD
5 mA
0.01
0.04
0.1
-1 mA
I
LOAD
0 mA
0.04
0.12
-5 mA
I
LOAD
-1 mA
0.01
V
IN
-V
OUT
Dropout Voltage
(Note 6)
I
LOAD
= 0 mA
45
65
100
mV
I
LOAD
= +1 mA
120
150
200
I
LOAD
= +5 mA
180
210
300
V
N
Output Noise Voltage
(Note 8)
0.1 Hz to 10 Hz
20
V
PP
10 Hz to 10 kHz
36
V
PP
I
S
Supply Current
160
257
290
A
I
SC
Short Circuit Current
V
OUT
= 0
15
mA
6
30
V
IN
= 6V, V
OUT
= 0
17
6
30
Hyst
Thermal Hysteresis
(Note 7)
-40C
T
A
125C
0.5
mV/V
V
OUT
Long Term Stability
(Note 9)
1000 hrs.
@
25C
100
ppm
LM4125
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4
Note 1: "Absolute Maximum Ratings" indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see Electrical Characteristics. The
guaranteed specifications apply only for the test conditions listed. Some performance characteristics may degrade when the device is not operated under the listed
test conditions.
Note 2: Without PCB copper enhancements. The maximum power dissipation must be de-rated at elevated temperatures and is limited by T
JMAX
(maximum
junction temperature),
J-A
(junction to ambient thermal resistance) and T
A
(ambient temperature). The maximum power dissipation at any temperature is: PDiss
MAX
= (T
JMAX
- T
A
)/
J-A
up to the value listed in the Absolute Maximum Ratings.
Note 3: The human body model is a 100 pF capacitor discharged through a 1.5 k
resistor into each pin. The machine model is a 200 pF capacitor discharged
directly into each pin.
Note 4: Typical numbers are at 25C and represent the most likely parametric norm.
Note 5: Limits are 100% production tested at 25C. Limits over the operating temperature range are guaranteed through correlation using Statistical Quality Control
(SQC) methods. The limits are used to calculate National's Averaging Outgoing Quality Level (AOQL).
Note 6: Dropout voltage is the differential voltage between V
OUT
and V
IN
at which V
OUT
changes
1% from V
OUT
at V
IN
= 3.3V for 2.0V, 2.5V and 5V for 4.1V. A
parasitic diode exists between input and output pins; it will conduct if V
OUT
is pulled to a higher voltage than V
IN
.
Note 7: Thermal hysteresis is defined as the change in +25C output voltage before and after exposing the device to temperature extremes.
Note 8: Output noise voltage is proportional to V
OUT
. V
N
for other voltage option is calculated using (V
N(1.8V)
/1.8) * V
OUT
. V
N
(2.5V) = (36V
PP
/1.8) * 2.5 = 46V
PP
.
Note 9: Long term stability is change in V
REF
at 25C measured continuously during 1000 hrs.
LM4125
www.national.com
5
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