NSC LM4132AMF-2.5

LM4132
SOT-23 Precision Low Dropout Voltage Reference
General Description
Features
The LM4132 family of precision voltage references performs
comparable to the best laser-trimmed bipolar references, but
in cost effective CMOS technology. The key to this break
through is the use of EEPROM registers for correction of
curvature, tempco, and accuracy on a CMOS bandgap architecture that allows package level programming to overcome assembly shift. The shifts in voltage accuracy and
tempco during assembly of die into plastic packages limit the
accuracy of references trimmed with laser techniques.
Unlike other LDO references, the LM4132 is capable of
delivering up to 20mA and does not require an output capacitor or buffer amplifier. These advantages and the SOT23
packaging are important for space-critical applications.
Series references provide lower power consumption than
shunt references, since they do not have to idle the maximum possible load current under no load conditions. This
advantage, the low quiescent current (60µA), and the low
dropout voltage (400mV) make the LM4132 ideal for batterypowered solutions.
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The LM4132 is available in five grades (A, B, C, D and E) for
greater flexibility. The best grade devices (A) have an initial
accuracy of 0.05% with guaranteed temperature coefficient
of 10ppm/˚C or less, while the lowest grade parts (E) have
an initial accuracy of 0.5% and a tempco of 30ppm/˚C.
Output initial voltage accuracy 0.05%
Low temperature coefficient 10ppm/˚C
Low Supply Current, 60µA
Enable pin allowing a 3µA shutdown mode
20mA output current
Voltage options 1.8V, 2.048V, 2.5V, 3.0V, 3.3V, 4.096V
Custom voltage options available (1.8V to 4.096V)
VIN range of VREF + 400mV to 5.5V @ 10mA
Stable with low ESR ceramic capacitors
SOT23-5 Package
Applications
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Instrumentation & Process Control
Test Equipment
Data Acquisition Systems
Base Stations
Servo Systems
Portable, Battery Powered Equipment
Automotive & Industrial
Precision Regulators
Battery Chargers
Communications
Medical Equipment
Typical Application Circuit
20151301
*Note: The capacitor CIN is required and the capacitor COUT is optional.
© 2006 National Semiconductor Corporation
DS201513
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LM4132 SOT-23 Precision Low Dropout Voltage Reference
August 2006
LM4132
Connection Diagram
Top View
20151302
SOT23-5 Package
NS Package Number MF05A
Ordering Information
Input Output Voltage Accuracy at
25˚C And Temperature Coefficient
LM4132 Supplied as 1000
units, Tape and Reel
LM4132 Supplied as 3000 units,
Tape and Reel
Part Marking
0.05%, 10 ppm/˚C max (A grade)
LM4132AMF-1.8
LM4132AMFX-1.8
R4AA
LM4132AMF-2.0
LM4132AMFX-2.0
R4BA
LM4132AMF-2.5
LM4132AMFX-2.5
R4CA
LM4132AMF-3.0
LM4132AMFX-3.0
R4DA
LM4132AMF-3.3
LM4132AMFX-3.3
R4EA
0.1%, 20 ppm/˚C max (B grade)
0.2%, 20 ppm/˚C max (C grade)
0.4%, 20 ppm/˚C max (D grade)
0.5%, 30 ppm/˚C max (E grade)
LM4132AMF-4.1
LM4132AMFX-4.1
R4FA
LM4132BMF-1.8
LM4132BMFX-1.8
R4AB
LM4132BMF-2.0
LM4132BMFX-2.0
R4BB
LM4132BMF-2.5
LM4132BMFX-2.5
R4CB
LM4132BMF-3.0
LM4132BMFX-3.0
R4DB
LM4132BMF-3.3
LM4132BMFX-3.3
R4EB
LM4132BMF-4.1
LM4132BMFX-4.1
R4FB
LM4132CMF-1.8
LM4132CMFX-1.8
R4AC
LM4132CMF-2.0
LM4132CMFX-2.0
R4BC
LM4132CMF-2.5
LM4132CMFX-2.5
R4CC
LM4132CMF-3.0
LM4132CMFX-3.0
R4DC
LM4132CMF-3.3
LM4132CMFX-3.3
R4EC
LM4132CMF-4.1
LM4132CMFX-4.1
R4FC
LM4132DMF-1.8
LM4132DMFX-1.8
R4AD
LM4132DMF-2.0
LM4132DMFX-2.0
R4BD
LM4132DMF-2.5
LM4132DMFX-2.5
R4CD
LM4132DMF-3.0
LM4132DMFX-3.0
R4DD
LM4132DMF-3.3
LM4132DMFX-3.3
R4ED
LM4132DMF-4.1
LM4132DMFX-4.1
R4FD
LM4132EMF-1.8
LM4132EMFX-1.8
R4AE
LM4132EMF-2.0
LM4132EMFX-2.0
R4BE
LM4132EMF-2.5
LM4132EMFX-2.5
R4CE
LM4132EMF-3.0
LM4132EMFX-3.0
R4DE
LM4132EMF-3.3
LM4132EMFX-3.3
R4EE
LM4132EMF-4.1
LM4132EMFX-4.1
R4FE
Pin Descriptions
Pin #
Name
Function
1
N/C
No connect pin, leave floating
2
GND
Ground
3
EN
Enable pin
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4
VIN
Input supply
5
VREF
Reference output
2
Lead Temperature
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Infrared (15sec)
Maximum Voltage on any input
Vapor Phase (60 sec)
260˚C
215˚C
220˚C
ESD Susceptibility (Note 3)
Human Body Model
-0.3 to 6V
Output short circuit duration
(soldering, 10sec)
2kV
Indefinite
Power Dissipation (TA = 25˚C)
(Note 2)
Storage Temperature Range
Operating Ratings
350mW
Maximum Input Supply Voltage
−65˚C to 150˚C
5.5V
Maximum Enable Input Voltage
VIN
Maximum Load Current
20mA
Junction Temperature Range (TJ)
−40˚C to
+125˚C
Electrical Characteristics
LM4132-1.8 (VOUT = 1.8V) Limits in standard type are for TJ = 25˚C only, and limits in boldface type apply
over the junction temperature (TJ) range of -40˚C to +125˚C unless otherwise specified. Minimum and Maximum limits are
guaranteed through test, design, or statistical correlation. Typical values represent the most likely parametric norm at TJ =
25˚C, and are provided for reference purposes only. Unless otherwise specified VIN = 5V and ILOAD = 0
Symbol
VREF
TCVREF / ˚C
(Note 6)
Parameter
Conditions
Typ
Min
(Note
Max
(Note 4)
5)
(Note 4)
LM4132A-1.8
(A Grade - 0.05%)
-0.05
0.05
LM4132B-1.8
(B Grade - 0.1%)
-0.1
0.1
LM4132C-1.8
(C Grade - 0.2%)
-0.2
0.2
LM4132D-1.8
(D Grade - 0.4%)
-0.4
0.4
LM4132E-1.8
(E Grade - 0.5%)
-0.5
0.5
LM4132A-1.8
0˚C ≤ TJ ≤ + 85˚C
10
-40˚C ≤ TJ ≤ +125˚C
20
LM4132B-1.8
20
LM4132C-1.8
20
-40˚C ≤ TJ ≤ +125˚C
30
Supply Current
Supply Current in Shutdown
60
100
µA
EN = 0V
3
7
µA
120
ppm / mA
∆VREF/∆VIN
Line Regulation
VREF + 400mV ≤ VIN ≤ 5.5V
30
∆VREF/∆ILOAD
Load Regulation
0mA ≤ ILOAD ≤ 20mA
25
Long Term Stability (Note 7)
1000 Hrs
50
Thermal Hysteresis (Note 8)
-40˚C ≤ TJ ≤ +125˚C
75
∆VREF
VIN - VREF
ppm / ˚C
20
LM4132E-1.8
IQ_SD
%
Temperature Coefficient
LM4132D-1.8
IQ
Unit
Output Voltage Initial Accuracy
ppm / V
ppm
Dropout Voltage (Note 9)
ILOAD = 10mA
230
VN
Output Noise Voltage
0.1 Hz to 10 Hz
170
ISC
Short Circuit Current
75
mA
VIL
Enable Pin Maximum Low Input
Level
35
%VIN
VIH
Enable Pin Minimum High Input
Level
65
3
400
mV
µVPP
%VIN
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LM4132
Absolute Maximum Ratings (Note 1)
LM4132
Electrical Characteristics
LM4132-2.0 (VOUT = 2.048V)
Limits in standard type are for TJ = 25˚C only, and limits in boldface type apply over the junction temperature (TJ) range of -40˚C to +125˚C unless otherwise specified. Minimum and Maximum limits are
guaranteed through test, design, or statistical correlation. Typical values represent the most likely parametric norm at TJ =
25˚C, and are provided for reference purposes only. Unless otherwise specified VIN = 5V and ILOAD = 0
Symbol
VREF
TCVREF / ˚C
(Note 6)
Parameter
Conditions
Typ
Min
(Note
Max
(Note 4)
5)
(Note 4)
LM4132A-2.0
(A Grade - 0.05%)
-0.05
0.05
LM4132B-2.0
(B Grade - 0.1%)
-0.1
0.1
LM4132C-2.0
(C Grade - 0.2%)
-0.2
0.2
LM4132D-2.0
(D Grade - 0.4%)
-0.4
0.4
LM4132E-2.0
(E Grade - 0.5%)
-0.5
0.5
LM4132A-2.0
0˚C ≤ TJ ≤ + 85˚C
10
-40˚C ≤ TJ ≤ +125˚C
20
LM4132B-2.0
20
LM4132C-2.0
20
-40˚C ≤ TJ ≤ +125˚C
30
Supply Current
60
100
7
Supply Current in Shutdown
EN = 0V
3
∆VREF/∆VIN
Line Regulation
VREF + 400mV ≤ VIN ≤ 5.5V
30
∆VREF/∆ILOAD
Load Regulation
0mA ≤ ILOAD ≤ 20mA
25
Long Term Stability (Note 7)
1000 Hrs
50
Thermal Hysteresis (Note 8)
-40˚C ≤ TJ ≤ +125˚C
75
∆VREF
VIN - VREF
ppm / ˚C
20
LM4132E-2.0
IQ_SD
%
Temperature Coefficient
LM4132D-2.0
IQ
Unit
Output Voltage Initial Accuracy
µA
µA
ppm / V
120
ppm / mA
ppm
Dropout Voltage (Note 9)
ILOAD = 10mA
175
VN
Output Noise Voltage
0.1 Hz to 10 Hz
190
ISC
Short Circuit Current
75
mA
VIL
Enable Pin Maximum Low Input
Level
35
%VIN
VIH
Enable Pin Minimum High Input
Level
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65
4
400
mV
µVPP
%VIN
over the junction temperature (TJ) range of -40˚C to +125˚C unless otherwise specified. Minimum and Maximum limits are
guaranteed through test, design, or statistical correlation. Typical values represent the most likely parametric norm at TJ =
25˚C, and are provided for reference purposes only. Unless otherwise specified VIN = 5V and ILOAD = 0
Symbol
VREF
TCVREF / ˚C
(Note 6)
Parameter
Conditions
Min
(Note 4)
Typ
(Note 5)
(A Grade - 0.05%)
-0.05
0.05
LM4132B-2.5
(B Grade - 0.1%)
-0.1
0.1
LM4132C-2.5
(C Grade - 0.2%)
-0.2
0.2
LM4132D-2.5
(D Grade - 0.4%)
-0.4
0.4
LM4132E-2.5
(E Grade - 0.5%)
-0.5
0.5
Temperature Coefficient
LM4132A-2.5
0˚C ≤ TJ ≤ + 85˚C
10
-40˚C ≤ TJ ≤ +125˚C
20
LM4132B-2.5
20
LM4132C-2.5
20
-40˚C ≤ TJ ≤ +125˚C
30
Supply Current
60
100
µA
3
7
µA
120
ppm / mA
EN = 0V
∆VREF/∆VIN
Line Regulation
VREF + 400mV ≤ VIN ≤ 5.5V
50
∆VREF/∆ILOAD
Load Regulation
0mA ≤ ILOAD ≤ 20mA
25
Long Term Stability (Note 7)
1000 Hrs
50
Thermal Hysteresis (Note 8)
-40˚C ≤ TJ ≤ +125˚C
75
VIN - VREF
ppm / ˚C
20
Supply Current in Shutdown
∆VREF
%
LM4132A-2.5
LM4132E-2.5
IQ_SD
Unit
Output Voltage Initial Accuracy
LM4132D-2.5
IQ
Max
(Note 4)
ppm / V
ppm
Dropout Voltage (Note 9)
ILOAD = 10mA
175
VN
Output Noise Voltage
0.1 Hz to 10 Hz
240
ISC
Short Circuit Current
75
mA
VIL
Enable Pin Maximum Low Input
Level
35
%VIN
VIH
Enable Pin Minimum High Input
Level
65
5
400
mV
µVPP
%VIN
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LM4132
Electrical Characteristics
LM4132-2.5 (VOUT = 2.5V) Limits in standard type are for TJ = 25˚C only, and limits in boldface type apply
LM4132
Electrical Characteristics
LM4132-3.0 (VOUT = 3.0V) Limits in standard type are for TJ = 25˚C only, and limits in boldface type apply
over the junction temperature (TJ) range of -40˚C to +125˚C unless otherwise specified. Minimum and Maximum limits are
guaranteed through test, design, or statistical correlation. Typical values represent the most likely parametric norm at TJ =
25˚C, and are provided for reference purposes only. Unless otherwise specified VIN = 5V and ILOAD = 0
Symbol
VREF
TCVREF / ˚C
(Note 6)
Parameter
Conditions
Min
Typ
(Note 4) (Note 5)
(A Grade - 0.05%)
-0.05
0.05
LM4132B-3.0
(B Grade - 0.1%)
-0.1
0.1
LM4132C-3.0
(C Grade - 0.2%)
-0.2
0.2
LM4132D-3.0
(D Grade - 0.4%)
-0.4
0.4
LM4132E-3.0
(E Grade - 0.5%)
-0.5
0.5
Temperature Coefficient
LM4132A-3.0
0˚C ≤ TJ ≤ + 85˚C
10
-40˚C ≤ TJ ≤ +125˚C
20
LM4132B-3.0
20
LM4132C-3.0
20
-40˚C ≤ TJ ≤ +125˚C
30
Supply Current
60
100
µA
7
µA
120
ppm / mA
EN = 0V
3
∆VREF/∆VIN
Line Regulation
VREF + 400mV ≤ VIN ≤ 5.5V
70
∆VREF/∆ILOAD
Load Regulation
0mA ≤ ILOAD ≤ 20mA
25
Long Term Stability (Note 7)
1000 Hrs
50
Thermal Hysteresis (Note 8)
-40˚C ≤ TJ ≤ +125˚C
75
VIN - VREF
ppm / ˚C
20
Supply Current in Shutdown
∆VREF
%
LM4132A-3.0
LM4132E-3.0
IQ_SD
Unit
Output Voltage Initial Accuracy
LM4132D-3.0
IQ
Max
(Note 4)
ppm / V
ppm
Dropout Voltage (Note 9)
ILOAD = 10mA
175
VN
Output Noise Voltage
0.1 Hz to 10 Hz
285
ISC
Short Circuit Current
75
mA
VIL
Enable Pin Maximum Low Input
Level
35
%VIN
VIH
Enable Pin Minimum High Input
Level
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65
6
400
mV
µVPP
%VIN
over the junction temperature (TJ) range of -40˚C to +125˚C unless otherwise specified. Minimum and Maximum limits are
guaranteed through test, design, or statistical correlation. Typical values represent the most likely parametric norm at TJ =
25˚C, and are provided for reference purposes only. Unless otherwise specified VIN = 5V and ILOAD = 0
Symbol
VREF
TCVREF / ˚C
(Note 6)
Parameter
Conditions
Min
Typ
Max
(Note 4) (Note 5) (Note 4)
LM4132A-3.3
(A Grade - 0.05%)
-0.05
0.05
LM4132B-3.3
(B Grade - 0.1%)
-0.1
0.1
LM4132C-3.3
(C Grade - 0.2%)
-0.2
0.2
LM4132D-3.3
(D Grade - 0.4%)
-0.4
0.4
LM4132E-3.3
(E Grade - 0.5%)
-0.5
0.5
LM4132A-3.3
0˚C ≤ TJ ≤ + 85˚C
10
-40˚C ≤ TJ ≤ +125˚C
20
LM4132B-3.3
20
LM4132C-3.3
20
-40˚C ≤ TJ ≤ +125˚C
30
Supply Current
60
100
µA
3
7
µA
120
ppm / mA
Supply Current in Shutdown
EN = 0V
∆VREF/∆VIN
Line Regulation
VREF + 400mV ≤ VIN ≤ 5.5V
85
∆VREF/∆ILOAD
Load Regulation
0mA ≤ ILOAD ≤ 20mA
25
Long Term Stability (Note 7)
1000 Hrs
50
Thermal Hysteresis (Note 8)
-40˚C ≤ TJ ≤ +125˚C
75
∆VREF
VIN - VREF
ppm / ˚C
20
LM4132E-3.3
IQ_SD
%
Temperature Coefficient
LM4132D-3.3
IQ
Unit
Output Voltage Initial Accuracy
ppm / V
ppm
Dropout Voltage (Note 9)
ILOAD = 10mA
175
VN
Output Noise Voltage
0.1 Hz to 10 Hz
310
ISC
Short Circuit Current
75
mA
VIL
Enable Pin Maximum Low Input
Level
35
%VIN
VIH
Enable Pin Minimum High Input
Level
65
7
400
mV
µVPP
%VIN
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LM4132
Electrical Characteristics
LM4132-3.3 (VOUT = 3.3V) Limits in standard type are for TJ = 25˚C only, and limits in boldface type apply
LM4132
Electrical Characteristics
LM4132-4.1 (VOUT = 4.096V)
Limits in standard type are for TJ = 25˚C only, and limits in boldface type apply over the junction temperature (TJ) range of -40˚C to +125˚C unless otherwise specified. Minimum and Maximum limits are
guaranteed through test, design, or statistical correlation. Typical values represent the most likely parametric norm at TJ =
25˚C, and are provided for reference purposes only. Unless otherwise specified VIN = 5V and ILOAD = 0
Symbol
VREF
TCVREF / ˚C
(Note 6)
Parameter
Conditions
Typ
Min
(Note
Max
(Note 4)
5)
(Note 4)
LM4132A-4.1
(A Grade - 0.05%)
-0.05
0.05
LM4132B-4.1
(B Grade - 0.1%)
-0.1
0.1
LM4132C-4.1
(C Grade - 0.2%)
-0.2
0.2
LM4132D-4.1
(D Grade - 0.4%)
-0.4
0.4
LM4132E-4.1
(E Grade - 0.5%)
-0.5
0.5
LM4132A-4.1
0˚C ≤ TJ ≤ + 85˚C
10
-40˚C ≤ TJ ≤ +125˚C
20
LM4132B-4.1
20
LM4132C-4.1
20
-40˚C ≤ TJ ≤ +125˚C
30
Supply Current
60
100
3
7
Supply Current in Shutdown
EN = 0V
∆VREF/∆VIN
Line Regulation
VREF + 400mV ≤ VIN ≤ 5.5V
∆VREF/∆ILOAD
Load Regulation
0mA ≤ ILOAD ≤ 20mA
25
Long Term Stability (Note 7)
1000 Hrs
50
Thermal Hysteresis (Note 8)
-40˚C ≤ TJ ≤ +125˚C
75
∆VREF
VIN - VREF
ppm / ˚C
20
LM4132E-4.1
IQ_SD
%
Temperature Coefficient
LM4132D-4.1
IQ
Unit
Output Voltage Initial Accuracy
100
µA
µA
ppm / V
120
ppm / mA
ppm
Dropout Voltage (Note 9)
ILOAD = 10mA
175
VN
Output Noise Voltage
0.1 Hz to 10 Hz
350
400
ISC
Short Circuit Current
75
mA
VIL
Enable Pin Maximum Low Input
Level
35
%VIN
VIH
Enable Pin Minimum High Input
Level
65
mV
µVPP
%VIN
Note 1: Absolute Maximum Ratings indicate limits beyond which damage may occur to the device. Operating Ratings indicate conditions for which the device is
intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications, see Electrical Characteristics.
Note 2: Without PCB copper enhancements. The maximum power dissipation must be de-rated at elevated temperatures and is limited by TJMAX (maximum
junction temperature), θJ-A (junction to ambient thermal resistance) and TA (ambient temperature). The maximum power dissipation at any temperature is: PDissMAX
= (TJMAX - TA) /θJ-A up to the value listed in the Absolute Maximum Ratings. θJ-A for SOT23-5 package is 220˚C/W, TJMAX = 125˚C.
Note 3: The human body model is a 100 pF capacitor discharged through a 1.5 kΩ resistor into each pin.
Note 4: Limits are 100% production tested at 25˚C. Limits over the operating temperature range are guaranteed through correlation using Statistical Quality Control.
Note 5: Typical numbers are at 25˚C and represent the most likely parametric norm.
Note 6: Temperature coefficient is measured by the "Box" method; i.e., the maximum ∆VREF is divided by the maximum ∆T.
Note 7: Long term stability is VREF @ 25˚C measured during 1000 hrs.
Note 8: Thermal hysteresis is defined as the change in +25˚C output voltage before and after cycling the device from (-40˚C to 125˚C).
Note 9: Dropout voltage is defined as the minimum input to output differential at which the output voltage drops by 0.5% below the value measured with a 5V input.
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LM4132
Typical Performance Characteristics for 1.8V
Output Voltage vs Temperature
Load Regulation
20151364
20151367
Line Regulation
0.1-10Hz Noise Spectrum
20151379
20151368
Output Voltage Noise Spectrum
Power Supply Rejection vs Frequency
20151376
20151373
9
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LM4132
Typical Performance Characteristics for 2.048V
Output Voltage vs Temperature
Load Regulation
20151304
20151303
Line Regulation
0.1 - 10 Hz Noise
20151314
20151309
Output Voltage Noise Spectrum
Power Supply Rejection vs Frequency
20151340
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20151315
10
LM4132
Typical Performance Characteristics for 2.5V
Output Voltage vs Temperature
Load Regulation
20151354
20151355
Line Regulation
0.1 - 10 Hz Noise
20151321
20151356
Output Voltage Noise Spectrum
Power Supply Rejection vs Frequency
20151357
20151358
11
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LM4132
Typical Performance Characteristics for 3.0V
Output Voltage vs Temperature
Load Regulation
20151365
20151369
Line Regulation
0.1-10 Hz Noise Spectrum
20151380
20151370
Output Voltage Noise Spectrum
Power Supply Rejection vs Frequency
20151374
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20151377
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LM4132
Typical Performance Characteristics for 3.3V
Output Voltage vs Temperature
Load Regulation
20151366
20151371
Line Regulation
0.1-10 Hz Noise Spectrum
20151381
20151372
Output Voltage Noise Spectrum
Power Supply Rejection vs Frequency
20151378
20151375
13
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LM4132
Typical Performance Characteristics for 4.096V
Output Voltage vs Temperature
Load Regulation
20151360
20151359
Line Regulation
0.1 - 10 Hz Noise
20151319
20151361
Output Voltage Noise Spectrum
Power Supply Rejection vs Frequency
20151362
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20151363
14
LM4132
Typical Performance Characteristics
Dropout vs Load to 0.5% Accuracy
Supply Current vs Input Voltage
20151308
20151353
Enable Threshold Voltage and Hysteresis
Shutdown IQ vs Temperature
20151310
20151317
Typical Long Term Stability
Ground Current vs Load Current
20151330
20151318
15
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LM4132
Typical Performance Characteristics
(Continued)
Typical Thermal Hysteresis
Turn-On Transient Response
20151352
20151331
Line Transient Response
VIN = 4V to 5.5V
Load Transient Response
ILOAD = 0 to 10mA
20151350
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20151351
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Thermal hysteresis is defined as the change in output voltage at 25oC after some deviation from 25oC. This is to say
that thermal hysteresis is the difference in output voltage
between two points in a given temperature profile. An illustrative temperature profile is shown in Figure 1.
THEORY OF OPERATION
The foundation of any voltage reference is the band-gap
circuit. While the reference in the LM4132 is developed from
the gate-source voltage of transistors in the IC, principles of
the band-gap circuit are easily understood using a bipolar
example. For a detailed analysis of the bipolar band-gap
circuit, please refer to Application Note AN-56.
SUPPLY AND ENABLE VOLTAGES
To ensure proper operation, VEN and VIN must be within a
specified range. An acceptable range of input voltages is
VIN > VREF + 400mV (ILOAD ≤ 10mA)
The enable pin uses an internal pull-up current source (IPULL_UP ) 2µA) that may be left floating or triggered by an
external source. If the part is not enabled by an external
source, it may be connected to VIN. An acceptable range of
enable voltages is given by the enable transfer characteristics. See the Electrical Characteristics section and Enable
Transfer Characteristics figure for more detail. Note, the part
will not operate correctly for VEN > VIN.
20151338
FIGURE 1. Illustrative Temperature Profile
This may be expressed analytically as the following:
COMPONENT SELECTION
A small ceramic (X5R or X7R) capacitor on the input must be
used to ensure stable operation. The value of CIN must be
sized according to the output capacitor value. The value of
CIN must satisfy the relationship CIN ≥ COUT. When no output
capacitor is used, CIN must have a minimum value of 0.1µF.
Noise on the power-supply input may affect the output noise.
Larger input capacitor values (typically 4.7µF to 22µF) may
help reduce noise on the output and significantly reduce
overshoot during startup. Use of an additional optional bypass capacitor between the input and ground may help
further reduce noise on the output. With an input capacitor,
the LM4132 will drive any combination of resistance and
capacitance up to VREF/20mA and 10µF respectively.
The LM4132 is designed to operate with or without an output
capacitor and is stable with capacitive loads up to 10µF.
Connecting a capacitor between the output and ground will
significantly improve the load transient response when
switching from a light load to a heavy load. The output
capacitor should not be made arbitrarily large because it will
effect the turn-on time as well as line and load transients.
While a variety of capacitor chemistry types may be used, it
is typically advisable to use low esr ceramic capacitors. Such
capacitors provide a low impedance to high frequency signals, effectively bypassing them to ground. Bypass capacitors should be mounted close to the part. Mounting bypass
capacitors close to the part will help reduce the parasitic
trace components thereby improving performance.
Where
VHYS = Thermal hysteresis expressed in ppm
VREF = Nominal preset output voltage
VREF1 = VREF before temperature fluctuation
VREF2 = VREF after temperature fluctuation.
The LM4132 features a low thermal hysteresis of 75 ppm
(typical) from -40˚C to 125˚C after 8 temperature cycles.
TEMPERATURE COEFFICIENT
Temperature drift is defined as the maximum deviation in
output voltage over the operating temperature range. This
deviation over temperature may be illustrated as shown in
Figure 2.
SHORT CIRCUITED OUTPUT
The LM4132 features indefinite short circuit protection. This
protection limits the output current to 75mA when the output
is shorted to ground.
20151339
FIGURE 2. Illustrative VREF vs Temperature Profile
TURN ON TIME
Turn on time is defined as the time taken for the output
voltage to rise to 90% of the preset value. The turn on time
depends on the load. The turn on time is typically 33.2µs
when driving a 1µF load and 78.8µs when driving a 10µF
load. Some users may experience an extended turn on time
(up to 10ms) under brown out conditions and low temperatures (-40˚C).
Temperature coefficient may be expressed analytically as
the following:
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LM4132
THERMAL HYSTERESIS
Application Information
LM4132
Application Information
(Continued)
TD = Temperature drift
VREF = Nominal preset output voltage
VREF_MIN = Minimum output voltage over operating
temperature range
VREF_MAX = Maximum output voltage over operating
temperature range
Where:
VREF is in volts (V) and VERROR is in milli-volts (mV).
Voltage error (mV) to percentage error (percent):
∆T = Operating temperature range.
The LM4132 features a low temperature drift of 10ppm
(max) to 30ppm (max), depending on the grade.
LONG TERM STABILITY
Long-term stability refers to the fluctuation in output voltage
over a long period of time (1000 hours). The LM4132 features a typical long-term stability of 50ppm over 1000 hours.
The measurements are made using 5 units of each voltage
option, at a nominal input voltage (5V), with no load, at room
temperature.
Where:
VREF is in volts (V) and VERROR is in milli-volts (mV).
PRINTED CIRCUIT BOARD and LAYOUT
CONSIDERATIONS
References in SOT packages are generally less prone to PC
board mounting than devices in Small Outline (SOIC) packages. To minimize the mechanical stress due to PC board
mounting that can cause the output voltage to shift from its
initial value, mount the reference on a low flex area of the PC
board, such as near the edge or a corner.
The part may be isolated mechanically by cutting a U shape
slot on the PCB for mounting the device. This approach also
provides some thermal isolation from the rest of the circuit.
EXPRESSION OF ELECTRICAL CHARACTERISTICS
Electrical characteristics are typically expressed in mV, ppm,
or a percentage of the nominal value. Depending on the
application, one expression may be more useful than the
other. To convert one quantity to the other one may apply the
following:
ppm to mV error in output voltage:
Bypass capacitors must be mounted close to the part.
Mounting bypass capacitors close to the part will reduce the
parasitic trace components thereby improving performance.
Where:
VREF is in volts (V) and VERROR is in milli-volts (mV).
Bit error (1 bit) to voltage error (mV):
VREF is in volts (V), VERROR is in milli-volts (mV), and n is the
number of bits.
mV to ppm error in output voltage:
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18
LM4132
Typical Application Circuits
20151326
FIGURE 3. Voltage Reference with Complimentary Output
20151327
FIGURE 4. Precision Voltage Reference with Force and Sense Output
20151328
FIGURE 5. Programmable Current Source
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LM4132 SOT-23 Precision Low Dropout Voltage Reference
Physical Dimensions
inches (millimeters) unless otherwise noted
SOT23-5 Package
NS Package Number MF05A
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves
the right at any time without notice to change said circuitry and specifications.
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