LMV431/LMV431A/LMV431B
Low-Voltage (1.24V) Adjustable Precision Shunt
Regulators
General Description
The LMV431, LMV431A and LMV431B are precision 1.24V
shunt regulators capable of adjustment to 30V. Negative
feedback from the cathode to the adjust pin controls the
cathode voltage, much like a non-inverting op amp configu-
ration (Refer to Symbol and Functional diagrams). A two
resistor voltage divider terminated at the adjust pin controls
the gain of a 1.24V band-gap reference. Shorting the cath-
ode to the adjust pin (voltage follower) provides a cathode
voltage of a 1.24V.
The LMV431, LMV431A and LMV431B have respective ini-
tial tolerances of 1.5%, 1% and 0.5%, and functionally lends
themselves to several applications that require zener diode
type performance at low voltages. Applications include a 3V
to 2.7V low drop-out regulator, an error amplifier in a 3V
off-line switching regulator and even as a voltage detector.
These parts are typically stable with capacitive loads greater
than 10nF and less than 50pF.
The LMV431, LMV431A and LMV431B provide performance
at a competitive price.
Features
n
Low Voltage Operation/Wide Adjust Range (1.24V/30V)
n
0.5% Initial Tolerance (LMV431B)
n
Temperature Compensated for Industrial Temperature
Range (39 PPM/C for the LMV431AI)
n
Low Operation Current (55A)
n
Low Output Impedance (0.25
)
n
Fast Turn-On Response
n
Low Cost
Applications
n
Shunt Regulator
n
Series Regulator
n
Current Source or Sink
n
Voltage Monitor
n
Error Amplifier
n
3V Off-Line Switching Regulator
n
Low Dropout N-Channel Series Regulator
Connection Diagrams
TO92: Plastic Package
10095801
Top View
SOT23-5
10095844
*Pin 1 is not internally connected.
*Pin 2 is internally connected to Anode pin. Pin 2 should be either floating
or connected to Anode pin.
Top View
SOT23-3
10095867
Top View
August 2003
LMV431/LMV431A/LMV431B
Low-V
oltage
(1.24V)
Adjustable
Precision
Shunt
Regulators
2003 National Semiconductor Corporation
DS100958
www.national.com
Symbol and Functional Diagrams
10095859
10095860
Simplified Schematic
10095803
LMV431/LMV431A/LMV431B
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2
Ordering Information
Package
Temperature
Range
Voltage Tolerance
Part Number
Package Marking
NSC Drawing
TO92
Industrial Range
-40C to +85C
1%
LMV431AIZ
LMV431AIZ
Z03A
1.5%
LMV431IZ
LMV431IZ
Commerial Range
0C to +70C
0.5%
LMV431BCZ
LMV431BCZ
1%
LMV431ACZ
LMV431ACZ
1.5%
LMV431CZ
LMV431CZ
SOT23-5
Industrial Range
-40C to +85C
1%
LMV431AIM5
N08A
MF05A
1%
LMV431AIM5X
N08A
1.5%
LMV431IM5
N08B
1.5%
LMV431IM5X
N08B
Commercial Range
0C to +70C
0.5%
LMV431BCM5
N09C
0.5%
LMV431BCM5X
N09C
1%
LMV431ACM5
N09A
1%
LMV431ACM5X
N09A
1.5%
LMV431CM5
N09B
1.5%
LMV431CM5X
N09B
SOT23-3
Industrial Range
-40 to +85C
0.5%
LMV431BIMF
RLB
MF03A
0.5%
LMV431BIMFX
1%
LMV431AIMF
RLA
1%
LMV431AIMFX
DC/AC Test Circuits for Table and
Curves
10095804
FIGURE 1. Test Circuit for V
Z
= V
REF
10095805
Note:
V
Z
= V
REF
(1 + R1/R2) + I
REF
R1
FIGURE 2. Test Circuit for V
Z
>
V
REF
10095806
FIGURE 3. Test Circuit for Off-State Current
LMV431/LMV431A/LMV431B
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3
Absolute Maximum Ratings
(Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Storage Temperature Range
-65C to +150C
Operating Temperature Range
Industrial (LMV431AI, LMV431I)
-40C to +85C
Commercial (LMV431AC,
LMV431C,
LMV431BC)
0C to +70C
Lead Temperature
TO92 Package/SOT23 -5,-3 Package
(Soldering, 10 sec.)
265C
Internal Power Dissipation (Note 2)
TO92
0.78W
SOT23-5, -3 Package
0.28W
Cathode Voltage
35V
Continuous Cathode Current
-30 mA to +30mA
Reference Input Current range
-.05mA to 3mA
Operating Conditions
Cathode Voltage
V
REF
to 30V
Cathode Current
0.1 mA to 15mA
Temperature range
LMV431AI
-40C
T
A
85C
Thermal Resistance (
JA
)(Note 3)
SOT23-5, -3 Package
455 C/W
TO-92 Package
161 C/W
Derating Curve (Slope = -1/
JA
)
10095830
LMV431C Electrical Characteristics
T
A
= 25C unless otherwise specified
Symbol
Parameter
Conditions
Min
Typ
Max
Units
V
REF
Reference Voltage
V
Z
= V
REF
, I
Z
= 10mA
(See Figure 1 )
T
A
= 25C
1.222
1.24
1.258
T
A
= Full Range
1.21
1.27
V
V
DEV
Deviation of Reference Input Voltage
Over Temperature (Note 4)
V
Z
= V
REF
, I
Z
= 10mA,
T
A
= Full Range (See Figure 1)
4
12
mV
Ratio of the Change in Reference
Voltage to the Change in Cathode
Voltage
I
Z
= 10mA (see Figure 2 )
V
Z
from V
REF
to 6V
R
1
= 10k, R
2
=
and 2.6k
-1.5
-2.7
mV/V
I
REF
Reference Input Current
R
1
= 10k
, R
2
=
I
I
= 10mA (see Figure 2)
0.15
0.5
A
I
REF
Deviation of Reference Input Current
over Temperature
R
1
= 10k
, R
2
=
,
I
I
= 10mA, T
A
= Full Range (see Figure 2)
0.05
0.3
A
I
Z(MIN)
Minimum Cathode Current for
Regulation
V
Z
= V
REF
(see Figure 1)
55
80
A
I
Z(OFF)
Off-State Current
V
Z
=6V, V
REF
= 0V (see Figure 3 )
0.001
0.1
A
r
Z
Dynamic Output Impedance (Note 5)
V
Z
= V
REF
, I
Z
= 0.1mA to 15mA
Frequency = 0Hz (see Figure 1)
0.25
0.4
LMV431/LMV431A/LMV431B
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LMV431I Electrical Characteristics
T
A
= 25C unless otherwise specified
Symbol
Parameter
Conditions
Min
Typ
Max
Units
V
REF
Reference Voltage
V
Z
= V
REF
, I
Z
= 10mA
(See Figure 1 )
T
A
= 25C
1.222
1.24
1.258
V
T
A
= Full Range
1.202
1.278
V
DEV
Deviation of Reference Input Voltage
Over Temperature (Note 4)
V
Z
= V
REF
, I
Z
= 10mA,
T
A
= Full Range (See Figure 1)
6
20
mV
Ratio of the Change in Reference
Voltage to the Change in Cathode
Voltage
I
Z
= 10mA (see Figure 2 )
V
Z
from V
REF
to 6V
R
1
= 10k, R
2
=
and 2.6k
-1.5
-2.7
mV/V
I
REF
Reference Input Current
R
1
= 10k
, R
2
=
I
I
= 10mA (see Figure 2)
0.15
0.5
A
I
REF
Deviation of Reference Input Current
over Temperature
R
1
= 10k
, R
2
=
,
I
I
= 10mA, T
A
= Full Range (see Figure 2)
0.1
0.4
A
I
Z(MIN)
Minimum Cathode Current for
Regulation
V
Z
= V
REF
(see Figure 1)
55
80
A
I
Z(OFF)
Off-State Current
V
Z
= 6V, V
REF
= 0V (see Figure 3 )
0.001
0.1
A
r
Z
Dynamic Output Impedance (Note 5)
V
Z
= V
REF
, I
Z
= 0.1mA to 15mA
Frequency = 0Hz (see Figure 1)
0.25
0.4
LMV431AC Electrical Characteristics
T
A
= 25C unless otherwise specified
Symbol
Parameter
Conditions
Min
Typ
Max
Units
V
REF
Reference Voltage
V
Z
= V
REF
, I
Z
= 10 mA
(See Figure 1 )
T
A
= 25C
1.228
1.24
1.252
V
T
A
= Full Range
1.221
1.259
V
DEV
Deviation of Reference Input Voltage
Over Temperature (Note 4)
V
Z
= V
REF
, I
Z
= 10mA,
T
A
= Full Range (See Figure 1)
4
12
mV
Ratio of the Change in Reference
Voltage to the Change in Cathode
Voltage
I
Z
= 10 mA (see Figure 2 )
V
Z
from V
REF
to 6V
R
1
= 10k, R
2
=
and 2.6k
-1.5
-2.7
mV/V
I
REF
Reference Input Current
R
1
= 1 k
, R
2
=
I
I
= 10 mA (see Figure 2)
0.15
0.50
A
I
REF
Deviation of Reference Input Current
over Temperature
R
1
= 10 k
, R
2
=
,
I
I
= 10 mA, T
A
= Full Range (see Figure 2)
0.05
0.3
A
I
Z(MIN)
Minimum Cathode Current for
Regulation
V
Z
= V
REF
(see Figure 1)
55
80
A
I
Z(OFF)
Off-State Current
V
Z
= 6V, V
REF
= 0V (see Figure 3 )
0.001
0.1
A
r
Z
Dynamic Output Impedance (Note 5)
V
Z
= V
REF
, I
Z
= 0.1mA to 15mA
Frequency = 0 Hz (see Figure 1)
0.25
0.4
LMV431/LMV431A/LMV431B
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