Datasheet LM4051AIM3X-ADJ, LM4051AIM3-ADJ, LM4051AIM3-1.2, LM4051CIM3X-ADJ, LM4051CIM3X-1.2 Datasheet (NSC)

LM4051
Precision Micropower Shunt Voltage Reference

LM4051 Precision Micropower Shunt Voltage Reference

February 2000

General Description

Ideal for space critical applications, the LM4051 precision
voltage reference is available in the sub-miniature (3 mm x

1.3 mm) SSOT-23 surface-mount package. The LM4051’s
advanced designeliminates the need for an external stabiliz­ing capacitor while ensuring stability with any capacitive
load, thus making the LM4051 easy to use. Further reducing
design effort is the availability of a fixed (1.225V) and adjust­able reverse breakdown voltage. The minimum operating
current is 60 µA for the LM4051-1.2 and the LM4051-ADJ.
Both versions have a maximum operating current of 12 mA.

The LM4051 comes in three grades (A, B, and C). The best
grade devices (A) have an initial accuracy of 0.1%, while the
B-grade have 0.2% and the C-grade 0.5%, all with a tempco
of 50 ppm/˚C guaranteed from −40˚C to 125˚C.

The LM4051 utilizes fuse and zener-zap trim of reference
voltage during wafer sort to ensure that the prime parts have
an accuracy of better than

±

0.1% (A grade) at 25˚C.

Features

n Small packages: SSOT-23
n No output capacitor required
n Tolerates capacitive loads
n Reverse breakdown voltage options of 1.225V and

adjustable

Key Specifications (LM4051-1.2)

n Output voltage tolerance

±

(A grade, 25˚C)

n Low output noise

(10 Hz to 10kHz) 20µV

n Wide operating current range 60µA to 12mA
n Industrial temperature range

(tempco guaranteed from

−40˚C to +125˚C)

n Low temperature coefficient 50 ppm/˚C (max)

0.1%(max)

rms

−40˚C to +85˚C

Applications

n Portable, Battery-Powered Equipment
n Data Acquisition Systems
n Instrumentation
n Process Control
n Energy Management
n Automotive and Industrial
n Precision Audio Components
n Base Stations
n Battery Chargers
n Medical Equipment
n Communication

Connection Diagrams

DS101222-1

*This pin must be left floating or connected to pin 2.

SSOT-23

DS101222-40

Top View

See NS Package Number MF03A

© 2000 National Semiconductor Corporation DS101222 www.national.com

Ordering Information

LM4051

±

±

±

Reverse Breakdown

Voltage Tolerance at 25˚C and

Average Reverse Breakdown

Voltage Temperature Coefficient

0.1%, 50 ppm/˚C max (A grade) LM4051AIM3-1.2 LM4051AIM3X-1.2 RIA

0.2%, 50 ppm/˚C max (B grade) LM4051BIM3-1.2 LM4051BIM3X-1.2 RIB

0.5%, 50 ppm/˚C max (C grade) LM4051CIM3-1.2 LM4051CIM3X-1.2 RIC

LM4051 Supplied as

1000 Units, Tape and

Reel

LM4051AIM3-ADJ LM4051AIM3X-ADJ RHA

LM4051BIM3-ADJ LM4051BIM3X-ADJ RHB

LM4051CIM3-ADJ LM4051CIM3X-ADJ RHC

SOT-23 Package Marking Information

Only three fields of marking are possible on the SSOT-23’s small surface. This
table gives the meaning of the three fields.

Field Definition

First Field:

R = Reference

Second Field:

I = 1.225V Voltage Option
H = Adjustable

Third Field:

A–C = Initial Reverse Breakdown

Voltage or Reference Voltage Tolerance

±

A=

0.1%, B =±0.2%, C =±0.5%

LM4051 Supplied as

3000 Units, Tape and

Reel

Part Marking

www.national.com 2

LM4051

Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.

Reverse Current 20 mA
Forward Current 10 mA
Maximum Output Voltage

(LM4051-ADJ) 15V

Power Dissipation (T

= 25˚C) (Note 2)

A

M3 Package 280 mW
Storage Temperature −65˚C to +150˚C
Lead Temperature
M3 Packages

Vapor phase (60 seconds) +215˚C
Infrared (15 seconds) +220˚C

LM4051-1.2
Electrical Characteristics

Boldface limits apply for TA=TJ=T

verse Breakdown Voltage tolerances of

Symbol Parameter Conditions

V

R

Reverse Breakdown
Voltage

Reverse Breakdown
Voltage

Tolerance (Note 6)

I

RMIN

Minimum Operating
Current

∆V

/∆T Average Reverse

R

Breakdown
Voltage Temperature
Coefficient (Note 6)

∆V

/∆IRReverse Breakdown

R

Voltage
Change with Operating
Current Change

Z

R

Reverse Dynamic
Impedance

to T

MIN

±

0.1%,±0.2% and±0.5% respectively.

; all other limits TA=TJ= 25˚C. The grades A, B and C designate initial Re-

MAX

IR= 100 µA 1.225 V

I

= 100 µA

R

=10mA

I

R

I

=1mA

R

I

= 100 µA

R

∆T = −40˚C to 125˚C

≤ IR≤ 1 mA 0.3 mV

I

RMIN

1mA≤I

≤12 mA 1.8 mV

R

IR= 1 mA, f = 120 Hz 0.5 Ω

ESD Susceptibility

Human Body Model (Note 3) 2 kV
Machine Model (Note 3) 200V

See AN-450 “Surface Mounting Methods and Their Effect
on Product Reliability” for other methods of soldering
surface mount devices.

Operating Ratings(Notes 1, 2)

Temperature Range (T
Industrial Temperature Range −40˚C ≤ T
Reverse Current

LM4051-1.2 60 µA to 12 mA
LM4051-ADJ 60 µA to 12 mA

Output Voltage Range

LM4051-ADJ 1.24V to 10V

Typical

(Note 4)

LM4051AIM3

(Limits)

(Note 5)

±

1.2

±

5.2

LM4051BIM3

(Limits)

(Note 5)

±

2.4

±

6.4

LM4051CIM3

Limts

(Note 5)

±

±

10.1 mV (max)

39 µA

60 60 60 µA (max)
65 65 65 µA (max)

±

20 ppm/˚C

±

15 ppm/˚C

±

15

±

50

±

50

±

1.1 1.1 1.1 mV (max)

1.5 1.5 1.5 mV (max)

6.0 6.0 6.0 mV (max)

8.0 8.0 8.0 mV (max)

≤ TA≤ T

min

6 mV (max)

50 ppm/˚C

≤ +85˚C

A

Units

(Limit)

(max)

max

)

e

N

Wideband Noise IR= 100 µA 20 µV

rms

10 Hz ≤ f ≤ 10 kHz

∆V

Reverse Breakdown

R

Voltage
Long Term Stability

t = 1000 hrs
T = 25˚C
I

R

±

= 100 µA

0.1˚C
120 ppm

(Note 9)

V

HYST

Output Hysteresis

∆T = −40˚C to 125˚C 0.36 mV/V

(Note 10)

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LM4051-ADJ (Adjustable)
Electrical Characteristics

LM4051

Boldface limits apply for TA=TJ=T

,I

≤ IR≤ 12 mA, V

RMIN

±

0.2% and±0.5%, respectively for V

REF

≤ V

OUT

Symbol Parameter Conditions

V

REF

Reference Voltage IR= 100 µA, V
Reference Voltage

Tolerance (Note 6),
(Note 8)

I

RMIN

Minimum Operating
Current

/∆IRReference

∆V

REF

VoltageChange with
Operating Current
Change

/∆VOReference Voltage

∆V

REF

Changewith Output
Voltage Change

I

FB

∆V

REF

Feedback Current 70

/∆T Average

ReferenceVoltage
Temperature
Coefficient (Note 8)

Z

OUT

Dynamic Output
Impedance

e

N

Wideband Noise IR= 100 µA

Reference Voltage

∆V

REF

Long Term Stability
(Note 9)

V

HYST

Output Hysteresis
(Note 10)

to T

MIN

≤ 10V. The grades A, B and C designate initial Reference Voltage Tolerances of±0.1%,

= 5V.

OUT

= 100 µA, V

I

R

≤ IR≤ 1mA

I

RMIN

≥ 1.6V

V

OUT

(Note 7)
1mA≤I

≥ 1.6V(Note 7)

V

OUT

= 0.1 mA −1.69

I

R

= 2.5V

V

OUT

I

= 10mA 20 ppm/˚C

R

I

= 1mA 15 ppm/˚C

R

I

= 100µA 15

R

∆T = −40˚C to +125˚C
IR= 1 mA,

f = 120 Hz,

= 0.1 I

I

AC

V

OUT=VREF

V

= 10V

OUT

V

OUT=VREF

10 Hz ≤ f ≤ 10 kHz
t = 1000 hrs,

= 100 µA

I

R

T = 25˚C
∆T = −40˚C to +125˚C 0.3 mV/V

; all other limits TJ= 25˚C unless otherwise specified (SSOT-23, see (Note 7)

MAX

Typical

(Note 4)

= 5V 1.212 V

OUT

=5V

OUT

LM4051AIM3

(Note 5)

±

1.2

±

5.2

LM4051BIM3

(Note 5)

±

2.4

±

6.4

LM4051CIM3

(Note 5)

±

6

±

10.1

36

60

65

60

65

65

70

0.3

≤12 mA

R

R

0.6

1.1

1.5

6

8

−2.8

−3.5

130

150

±

50

1.1

1.5

6

8

−2.8

−3.5

130

150

±

50

1.1

1.5

6

8

−2.8

−3.5

130

150

±

50 ppm/˚C

0.3
2

20 µV

120 ppm

±

0.1˚C

Units

(Limit)

mV (max)
mV (max)

µA
µA (max)
µA (max)

mV

mV (max)

mV(max)

mV
mV (max)
mV (max)

mV/V
mV/V (max)
mV/V (max)

nA
nA (max)
nA (max)

(max)

Ω
Ω

rms

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Electrical Characteristics (continued)

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is

functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the 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: The maximum power dissipation must be derated at elevated temperatures and is dictated by T
bient thermal resistance), and T
given in the Absolute Maximum Ratings, whichever is lower. For the LM4051, T
280˚C/W for the SSOT-23 package.

Note 3: The human body model is a 100 pF capacitor discharged through a 1.5 kΩ resistor into each pin. The machine model is a 200 pF capacitor discharged di-
rectly into each pin.

Note 4: Typicals are at T
Note 5: Limits are 100% production tested at 25˚C. Limits over temperature are guaranteed through correlation using Statistical Quality Control (SQC) methods.

The limits are used to calculate National’s AOQL.
Note 6: The boldface (over-temperature) limit for Reverse Breakdown Voltage Toleranceisdefinedastheroomtemperature Reverse Breakdown Voltage Tolerance

±

[(∆VR/∆T)(max ∆T)(VR)]. Where, ∆VR/∆T is the VRtemperature coefficient, max∆T is the maximum difference in temperature from the reference point of 25 ˚C to

or T

T

MAX

max∆T=65˚C is shown below:

, and VRis the reverse breakdown voltage. The total over-temperature tolerance for the different grades in the industrial temperature range where

MIN

(ambient temperature). The maximum allowable power dissipation at any temperature is PD

A

= 25˚C and represent most likely parametric norm.

J

= 125˚C, and the typical thermal resistance (θJA), when board mounted, is

Jmax

A-grade:±0.425% =±0.1%±50 ppm/˚C x 65˚C

±

B-grade:
C-grade:

Therefore, as an example, the A-grade LM4051-1.2 has an over-temperature Reverse Breakdown Voltage tolerance of±1.2V x 0.425% =±5.2 mV.
Note 7: When V

the die (-) output and the package (-) output pin. See the Output Saturation curve in the Typical Performance Characteristics section.

Note 8: Reference voltage and temperature coefficient will change with output voltage. See Typical Performance Characteristics curves.
Note 9: Long term stability is V
Note 10: Thermal hysteresis is defined as the changes in 25˚C output voltage before and after cycling the device from −40˚C or +125˚C.

≤ 1.6V, the LM4051-ADJ in the SSOT-23 package must operate at reduced IR. This is caused by the series resistance of the die attach between

OUT

@

25˚C measured during 1000 hrs.

R

0.522% =±0.2%±50 ppm/˚C x 65˚C

±

0.825% =±0.5%±50 ppm/˚C x 65˚C

(maximum junction temperature), θJA(junction to am-

Jmax

max

=(T

Jmax−TA

)/θJAor the number

LM4051

Typical Performance Characteristics

Temperature Drift for Different
Average Temperature Coefficient

DS101222-19

Output Impedance vs Frequency

DS101222-4

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Typical Performance Characteristics (Continued)

LM4051

Noise Voltage

Reverse Characteristics and
Minimum Operating Current

Start-Up
Characteristics

Reference Voltage vs Output
Voltage and Temperature

DS101222-5

DS101222-7

DS101222-9

DS101222-8

Reference Voltage vs Temperature
and Output Voltage

DS101222-11

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DS101222-10

Typical Performance Characteristics (Continued)

LM4051

Feedback Current vs Output
Voltage and Temperature

Output Impedance vs Frequency

DS101222-12

Output Saturation
(SOT-23 Only)

DS101222-33

Output Impedance vs Frequency

Reverse Characteristics

DS101222-13

DS101222-15

DS101222-14

DS101222-16

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Typical Performance Characteristics (Continued)

LM4051

Large Signal Response

DS101222-17

Thermal Hysteresis

DS101222-18

DS101222-50

Functional Block Diagram

*LM4051-ADJ only
**LM4051-1.2 only

DS101222-21

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Applications Information

The LM4051 is a precision micro-power curvature-corrected
bandgap shunt voltage reference. For space critical applica­tions, the LM4051 is available in the sub-miniature SSOT-23
surface-mount package. The LM4051 has been designed for
stable operation without the need of an external capacitor
connected between the “+” pin and the “−” pin. If, however,a
bypass capacitor is used, the LM4051 remains stable. De­sign effort is further reduced with the choice of either a fixed

1.2V or an adjustable reverse breakdown voltage. The mini­mum operating current is 60 µA for the LM4051-1.2 and the
LM4051-ADJ. Both versions have a maximum operating cur­rent of 12 mA.

LM4051s using the SSOT-23 package have pin 3 connected
as the (-) output through the package’s die attach interface.
Therefore, the LM4051-1.2’s pin 3 must be left floating or
connected to pin 2 and the LM4051-ADJ’s pin 3 is the (-) out­put.

In a conventional shunt regulator application
external series resistor (R
ply voltage and the LM4051. R
flows through the load (I

) is connected between the sup-

S

determines the current that

S

) and the LM4051 (IQ). Since load

L

current and supply voltage may vary, R
enough to supply at least the minimum acceptable I
LM4051 even when the supply voltage is at its minimum and
the load current is at its maximum value. When the supply
voltage is at its maximum and I

is at its minimum, RSshould

L

be large enough so that the current flowing through the
LM4051 is less than 12 mA.

R

should be selected based on the supply voltage, (VS), the

S

desired load and operating current, (I
LM4051’s reverse breakdown voltage, V

(Figure 1)

should be small

S

Q

and IQ), and the

L

.

R

,an

to the

where V
nal V

is the output voltage. The actual value of the inter-

O

is a function of VO. The “corrected” V

REF

REF

is deter-

mined by

V

REF=VO

(∆V

/∆VO)+V

REF

Y

(3)

where

V

= 1.22V

Y

∆V

/∆VOis found in the Electrical Characteristics and is

REF

typically −1.55 mV/V.You can get a more accurate indication
of the output voltage by replacing the value of V

REF

in equa-

tion (1) with the value found using equation (3).

Typical Applications

DS101222-22

FIGURE 1. Shunt Regulator

LM4051

The LM4051-ADJ’s output voltage can be adjusted to any
value in the range of 1.24V through 10V. It is a function of the
internal reference voltage (V
feedback resistors as shown in

) and the ratio of the external

REF

Figure 2

. The output voltage

is found using the equation

V

O=VREF

[(R2/R1) + 1] (1)

(2)

DS101222-34

FIGURE 2. Adjustable Shunt Regulator

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Typical Applications (Continued)

LM4051

FIGURE 3. Bounded amplifier reduces saturation-induced delays and can prevent succeeding stage damage.

Nominal clamping voltage is

DS101222-24

±

VO(LM4051’s reverse breakdown voltage) +2 diode VF.

DS101222-20

FIGURE 4. Voltage Level Detector

DS101222-23

FIGURE 5. Voltage Level Detector

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Typical Applications (Continued)

DS101222-25

FIGURE 6. Fast Positive Clamp

2.4V + V

D1

DS101222-35

FIGURE 8. Bidirectional Adjustable

±

Clamp

18V to±2.4V

LM4051

DS101222-26

FIGURE 7. Bidirectional Clamp±2.4V

FIGURE 10. Simple Floating Current Detector

DS101222-36

FIGURE 9. Bidirectional Adjustable

±

Clamp

2.4V to±6V

DS101222-37

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Typical Applications (Continued)

LM4051

FIGURE 11. Current Source

Note 11: *D1 can be any LED, VF= 1.5V to 2.2V at 3 mA. D1 may act as an indicator. D1 will be on if I

=O.

DS101222-38

THRESHOLD

falls below the threshold current, except with I

FIGURE 12. Precision Floating Current Detector

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DS101222-39

Typical Applications (Continued)

LM4051

DS101222-28

DS101222-29

FIGURE 13. Precision 1 µA to 1 mA Current Sources

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Physical Dimensions inches (millimeters) unless otherwise noted

Plastic Surface Mount Package (M3)

NS Package Number MF03A

(JEDEC Registration TO-236AB)

LM4051 Precision Micropower Shunt Voltage Reference

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whose failure to perform when properly used in
accordance with instructions for use provided in the
labeling, can be reasonably expected to result in a
significant injury to the user.

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Corporation

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