LM4120
Precision Micropower Low Dropout Voltage Reference
General Description
The LM4120 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 12V consuming 160 A (Typ.) supply current. In
power down mode, device current drops to less than 2 A.
The LM4120 comes in two grades (A and Standard) and
seven 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 LM4120 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 LM4120 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
Enable pin
n
Fixed output voltages:
1.8, 2.048, 2.5, 3.0, 3.3, 4.096
and 5.0V
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
Functional Block Diagram
Connection Diagram
DS101047-1
DS101047-2
Refer to the Ordering Information Table in this Data Sheet for Specific
Part Number
SOT23-5 Surface Mount Package
February 2000
LM4120
Precision
Micropower
Low
Dropout
V
oltage
Reference
2000 National Semiconductor Corporation
DS101047
www.national.com
Ordering Information
Industrial Temperature Range (-40C to + 85C)
Initial Output Voltage Accuracy at 25C
And Temperature Coefficient
LM4120 Supplied as
1000 Units, Tape and
Reel
LM4120 Supplied as
3000 Units, Tape and
Reel
Top
Marking
0.2%, 50 ppm/C max (A grade)
LM4120AIM5-1.8
LM4120AIM5X-1.8
R21A
LM4120AIM5-2.0
LM4120AIM5X-2.0
R14A
LM4120AIM5-2.5
LM4120AIM5X-2.5
R08A
LM4120AIM5-3.0
LM4120AIM5X-3.0
R15A
LM4120AIM5-3.3
LM4120AIM5X-3.3
R16A
LM4120AIM5-4.1
LM4120AIM5X-4.1
R17A
LM4120AIM5-5.0
LM4120AIM5X-5.0
R18A
0.5%, 50 ppm/C max
LM4120IM5-1.8
LM4120IM5X-1.8
R21B
LM4120IM5-2.0
LM4120IM5X-2.0
R14B
LM4120IM5-2.5
LM4120IM5X-2.5
R08B
LM4120IM5-3.0
LM4120IM5X-3.0
R15B
LM4120IM5-3.3
LM4120IM5X-3.3
R16B
LM4120IM5-4.1
LM4120IM5X-4.1
R17B
LM4120IM5-5.0
LM4120IM5X-5.0
R18B
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:
21 = 1.800V Voltage Option
14 = 2.048V Voltage Option
08 = 2.500V Voltage Option
15 = 3.000V Voltage Option
16 = 3.300V Voltage Option
17 = 4.096V Voltage Option
18 = 5.000V Voltage Option
Fourth Field:
A-B = Initial Reference Voltage Tolerance
A =
0.2%
B =
0.5%
LM4120
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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 14V
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
LM4120-1.8V, 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 tem-
perature range.
Symbol
Parameter
Conditions
Min (Note 5)
Typ (Note 4)
Max (Note 5)
Units
V
OUT
Output Voltage Initial
Accuracy
LM4120A-1.800
LM4120A-2.048
LM4120A-2.500
0.2
%
LM4120-1.800
LM4120-2.048
LM4120-2.500
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
12V
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
80
mV
I
LOAD
= +1 mA
120
150
180
I
LOAD
= +5 mA
180
210
250
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
250
275
A
I
SS
Power-down Supply Current
Enable = 0.4V
-40C
T
J
+85C
Enable = 0.2V
1
2
A
V
H
Logic High Input Voltage
2.4
V
2.4
V
L
Logic Low Input Voltage
0.4
V
0.2
I
H
Logic High Input Current
7
15
A
LM4120
www.national.com
3
Electrical Characteristics
LM4120-1.8V, 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
I
L
Logic Low Input Current
0.1
A
I
SC
Short Circuit Current
V
IN
= 3.3V, V
OUT
= 0
15
mA
6
30
V
IN
= 12V, 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
Electrical Characteristics
LM4120-3.0V, 3.3V, 4.096V and 5.0V
Unless otherwise specified V
IN
= V
OUT
+ 1V, 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
LM4120A-3.000
LM4120A-3.300
LM4120A-4.096
LM4120A-5.000
0.2
%
LM4120-3.000
LM4120-3.300
LM4120-4.096
LM4120-5.000
0.5
%
TCV
OUT
/C
Temperature Coefficient
-40C
T
A
+125C
14
50
ppm/c
V
OUT
/
V
IN
Line Regulation
(V
OUT
+ 1V)
V
IN
12V
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
80
mV
I
LOAD
= +1 mA
120
150
180
I
LOAD
= +5 mA
180
210
250
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
250
275
A
I
SS
Power-down Supply Current
Enable = 0.4V
-40C
T
J
+85C
Enable = 0.2V
1
2
A
LM4120
www.national.com
4
Electrical Characteristics
LM4120-3.0V, 3.3V, 4.096V and 5.0V
Unless otherwise specified V
IN
= V
OUT
+ 1V, 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
H
Logic High Input Voltage
2.4
V
2.4
V
L
Logic Low Input Voltage
0.4
V
0.2
I
H
Logic High Input Current
7
15
A
I
L
Logic Low Input Current
0.1
A
I
SC
Short Circuit Current
V
OUT
= 0
15
mA
6
30
V
IN
= 12V, 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
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 guar-
anteed 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 di-
rectly 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 1.8V, 2.0V, 2.5V and V
OUT
+
1V for others.For 1.8V option, dropout voltage is not guaranteed over temperature. 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.
LM4120 Typical Operating Characteristics
Unless otherwise specified, V
IN
= 3.3V, V
OUT
= 2.5V,
I
LOAD
= 0, C
OUT
= 0.022F, T
A
= 25C and V
EN
= V
IN
.
Long Term Drift
DS101047-12
Typical Temperature Drift
DS101047-13
Short Circuit Current vs
Temperature
DS101047-14
LM4120
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5
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