LM4051_技术文档

February 2000

LM4051

Precision Micropower Shunt Voltage Reference

General Description

Key Specifications (LM4051-1.2)

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 design eliminates the need for an external stabiliz-

ing 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 adjust-

able 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.

n Output voltage tolerance

(A grade, 25˚C)

±

0.1%(max)

n Low output noise

(10 Hz to 10kHz)

20µV_rms

n Wide operating current range

60µA to 12mA

−40˚C to +85˚C

n Industrial temperature range

(tempco guaranteed from

−40˚C to +125˚C)

n Low temperature coefficient

50 ppm/˚C (max)

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.

Applications

n Portable, Battery-Powered Equipment

n Data Acquisition Systems

n Instrumentation

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.

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

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

Connection Diagrams

SSOT-23

DS101222-40

DS101222-1

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

Top View

See NS Package Number MF03A

DS101222

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Ordering Information

Reverse Breakdown

LM4051 Supplied as

1000 Units, Tape and

Reel

LM4051 Supplied as

3000 Units, Tape and

Reel

Part Marking

Voltage Tolerance at 25˚C and

Average Reverse Breakdown

Voltage Temperature Coefficient

±

0.1%, 50 ppm/˚C max (A grade)

0.2%, 50 ppm/˚C max (B grade)

0.5%, 50 ppm/˚C max (C grade)

LM4051AIM3-1.2

LM4051AIM3-ADJ

LM4051BIM3-1.2

LM4051BIM3-ADJ

LM4051CIM3-1.2

LM4051CIM3-ADJ

LM4051AIM3X-1.2

LM4051AIM3X-ADJ

LM4051BIM3X-1.2

LM4051BIM3X-ADJ

LM4051CIM3X-1.2

LM4051CIM3X-ADJ

RIA

RHA

RIB

RHB

RIC

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%

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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.

ESD Susceptibility

Human Body Model (Note 3)

Machine Model (Note 3)

2 kV

200V

See AN-450 “Surface Mounting Methods and Their Effect

on Product Reliability” for other methods of soldering

surface mount devices.

Reverse Current

20 mA

10 mA

Forward Current

Maximum Output Voltage

(LM4051-ADJ)

Operating Ratings(Notes 1, 2)

15V

Temperature Range

Industrial Temperature Range

Reverse Current

LM4051-1.2

(T_min≤ T_A≤ T_max)

Power Dissipation (T_A= 25˚C) (Note 2)

M3 Package

−40˚C ≤ T_A≤ +85˚C

280 mW

Storage Temperature

Lead Temperature

−65˚C to +150˚C

60 µA to 12 mA

LM4051-ADJ

M3 Packages

Output Voltage Range

LM4051-ADJ

Vapor phase (60 seconds)

Infrared (15 seconds)

+215˚C

+220˚C

1.24V to 10V

LM4051-1.2

Electrical Characteristics

Boldface limits apply for T_A= T_J= T_MINto T_MAX; all other limits T_A= T_J= 25˚C. The grades A, B and C designate initial Re-

±

verse Breakdown Voltage tolerances of 0.1%, 0.2% and 0.5% respectively.

LM4051AIM3 LM4051BIM3 LM4051CIM3

Typical

(Note 4)

Units

(Limit)

Symbol

V_R

Parameter

Conditions

I_R= 100 µA

(Limits)

(Note 5)

Limts

(Note 5)

Reverse Breakdown

Voltage

1.225

V

±

6

Reverse Breakdown

Voltage

I_R= 100 µA

1.2

2.4

mV (max)

±

10.1

Tolerance (Note 6)

5.2

6.4

mV (max)

µA

I_RMIN

Minimum Operating

Current

39

60

µA (max)

ppm/˚C

65

±

∆V_R/∆T Average Reverse

Breakdown

I_R= 10 mA

I_R= 1 mA

20

15

Voltage Temperature

Coefficient (Note 6)

±

50

I_R= 100 µA

∆T = −40˚C to 125˚C

50

ppm/˚C

(max)

∆V_R/∆I_RReverse Breakdown

Voltage

I_RMIN≤ I_R≤ 1 mA

0.3

mV

1.1

mV (max)

mV

Change with Operating

Current Change

1.5

1 mA ≤ I_R≤ 12 mA

I_R= 1 mA, f = 120 Hz

1.8

6.0

mV (max)

Ω

8.0

Z_R

Reverse Dynamic

Impedance

0.5

20

e_N

Wideband Noise

I_R= 100 µA

µV_rms

10 Hz ≤ f ≤ 10 kHz

∆V_R

Reverse Breakdown

Voltage

t = 1000 hrs

±

T = 25˚C 0.1˚C

120

ppm

Long Term Stability

(Note 9)

I_R= 100 µA

V_HYST

Output Hysteresis

(Note 10)

∆T = −40˚C to 125˚C

0.36

mV/V

3

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LM4051-ADJ (Adjustable)

Electrical Characteristics

Boldface limits apply for T_A= T_J= T_MINto T_MAX; all other limits T_J= 25˚C unless otherwise specified (SSOT-23, see (Note 7)

±

, I_RMIN≤ I_R≤ 12 mA, V_REF≤ V_OUT≤ 10V. The grades A, B and C designate initial Reference Voltage Tolerances of 0.1%,

±

0.2% and 0.5%, respectively for V_OUT= 5V.

Typical LM4051AIM3 LM4051BIM3 LM4051CIM3

Units

(Limit)

Symbol

Parameter

Conditions

(Note 4)

(Note 5)

V_REF

Reference Voltage

I_R= 100 µA, V_OUT= 5V

1.212

V

±

6

±

10.1

Reference Voltage

Tolerance (Note 6),

(Note 8)

1.2

5.2

2.4

6.4

mV (max)

I_RMIN

Minimum Operating

Current

36

0.3

µA

µA (max)

60

65

60

65

70

∆V_REF/∆I_RReference

VoltageChange with

I_RMIN≤ I_R≤ 1mA

V_OUT≥ 1.6V

(Note 7)

mV

mV (max)

mV(max)

1.1

1.5

1.1

1.5

1.1

1.5

Operating Current

Change

1 mA ≤ I_R≤ 12 mA

V_OUT≥ 1.6V(Note 7)

0.6

mV

mV (max)

6

8

6

8

6

8

∆V_REF/∆V_OReference Voltage

Changewith Output

I_R= 0.1 mA

−1.69

70

mV/V

mV/V (max)

−2.8

−3.5

−2.8

−3.5

−2.8

−3.5

Voltage Change

I_FB

Feedback Current

nA

130

150

130

150

130

150

nA (max)

∆V_REF/∆T Average

ReferenceVoltage

V_OUT= 2.5V

I_R= 10mA

I_R= 1mA

20

15

ppm/˚C

Temperature

Coefficient (Note 8)

±

50

I_R= 100µA

50

ppm/˚C

(max)

∆T = −40˚C to +125˚C

Z_OUT

Dynamic Output

Impedance

I_R= 1 mA,

f = 120 Hz,

I_AC= 0.1 I_R

V_OUT= V_REF

0.3

2

Ω

V_OUT

= 10V

e_N

Wideband Noise

I_R= 100 µA

V_OUT= V_REF

10 Hz ≤ f ≤ 10 kHz

20

120

0.3

µV_rms

Reference Voltage

Long Term Stability

(Note 9)

t = 1000 hrs,

I_R= 100 µA

ppm

∆V_REF

±

T = 25˚C 0.1˚C

V_HYST

Output Hysteresis

(Note 10)

∆T = −40˚C to +125˚C

mV/V

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4

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 condi-

tions.

Note 2: The maximum power dissipation must be derated at elevated temperatures and is dictated by T

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

JA

Jmax

bient thermal resistance), and T (ambient temperature). The maximum allowable power dissipation at any temperature is PD

= (T

− T )/θ or the number

Jmax A JA

A

max

given in the Absolute Maximum Ratings, whichever is lower. For the LM4051, T

280˚C/W for the SSOT-23 package.

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

JA

Jmax

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 = 25˚C and represent most likely parametric norm.

J

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 Tolerance is defined as the room temperature Reverse Breakdown Voltage Tolerance

±

T

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

R

or T

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

R

MAX

MIN

max∆T=65˚C is shown below:

±

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

±

B-grade: 0.522% = 0.2% 50 ppm/˚C x 65˚C

±

C-grade: 0.825% = 0.5% 50 ppm/˚C x 65˚C

±

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

OUT

R

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

25˚C measured during 1000 hrs.

R

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.

Typical Performance Characteristics

Temperature Drift for Different

Average Temperature Coefficient

Output Impedance vs Frequency

DS101222-19

DS101222-4

5

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Typical Performance Characteristics (Continued)

Noise Voltage

Reverse Characteristics and

Minimum Operating Current

DS101222-5

DS101222-9

Start-Up

Characteristics

DS101222-8

DS101222-7

Reference Voltage vs Output

Voltage and Temperature

Reference Voltage vs Temperature

and Output Voltage

DS101222-11

DS101222-10

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6

Typical Performance Characteristics (Continued)

Feedback Current vs Output

Voltage and Temperature

Output Saturation

(SOT-23 Only)

DS101222-12

DS101222-33

Output Impedance vs Frequency

DS101222-13

DS101222-14

Reverse Characteristics

DS101222-16

DS101222-15

7

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Typical Performance Characteristics (Continued)

Large Signal Response

DS101222-18

DS101222-17

Thermal Hysteresis

DS101222-50

Functional Block Diagram

DS101222-21

*LM4051-ADJ only

**LM4051-1.2 only

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8

Applications Information

The LM4051 is a precision micro-power curvature-corrected

bandgap shunt voltage reference. For space critical applica-

tions, 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. De-

sign effort is further reduced with the choice of either a fixed

1.2V or an adjustable reverse breakdown voltage. The mini-

mum operating current is 60 µA for the LM4051-1.2 and the

LM4051-ADJ. Both versions have a maximum operating cur-

rent of 12 mA.

where V_Ois the output voltage. The actual value of the inter-

nal V_REFis a function of V_O. The “corrected” V_REFis deter-

mined by

V_REF= V_O(∆V_REF/∆V_O) + V_Y

(3)

where

V_Y= 1.22V

∆V_REF/∆V_Ois found in the Electrical Characteristics and is

typically −1.55 mV/V. You can get a more accurate indication

of the output voltage by replacing the value of V_REFin equa-

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

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 (-) out-

put.

Typical Applications

In a conventional shunt regulator application (Figure 1), an

external series resistor (R_S) is connected between the sup-

ply voltage and the LM4051. R_Sdetermines the current that

flows through the load (I_L) and the LM4051 (I_Q). Since load

current and supply voltage may vary, R_Sshould be small

enough to supply at least the minimum acceptable I_Qto the

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_Lis at its minimum, R_Sshould

be large enough so that the current flowing through the

LM4051 is less than 12 mA.

DS101222-22

FIGURE 1. Shunt Regulator

R_Sshould be selected based on the supply voltage, (V_S), the

desired load and operating current, (I_Land I_Q), and the

LM4051’s reverse breakdown voltage, V_R.

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_REF) and the ratio of the external

feedback resistors as shown in Figure 2 . The output voltage

is found using the equation

DS101222-34

FIGURE 2. Adjustable Shunt Regulator

V_O= V_REF[(R2/R1) + 1]

(1)

(2)

9

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Typical Applications (Continued)

DS101222-24

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

±

Nominal clamping voltage is V_O(LM4051’s reverse breakdown voltage) +2 diode V_F.

DS101222-20

DS101222-23

FIGURE 4. Voltage Level Detector

FIGURE 5. Voltage Level Detector

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10

Typical Applications (Continued)

DS101222-35

FIGURE 8. Bidirectional Adjustable

DS101222-25

±

Clamp 18V to 2.4V

FIGURE 6. Fast Positive Clamp

2.4V + V_D1

DS101222-26

±

FIGURE 7. Bidirectional Clamp 2.4V

DS101222-36

FIGURE 9. Bidirectional Adjustable

±

Clamp 2.4V to 6V

DS101222-37

FIGURE 10. Simple Floating Current Detector

11

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Typical Applications (Continued)

DS101222-38

FIGURE 11. Current Source

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

falls below the threshold current, except with I

F

THRESHOLD

= O.

DS101222-39

FIGURE 12. Precision Floating Current Detector

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12

Typical Applications (Continued)

DS101222-28

DS101222-29

FIGURE 13. Precision 1 µA to 1 mA Current Sources

13

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Physical Dimensions inches (millimeters) unless otherwise noted

Plastic Surface Mount Package (M3)

NS Package Number MF03A

(JEDEC Registration TO-236AB)

LIFE SUPPORT POLICY

NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT

DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL

COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:

1. Life support devices or systems are devices or

systems which, (a) are intended for surgical implant

into the body, or (b) support or sustain life, and

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.

2. A critical component is any component of a life

support device or system whose failure to perform

can be reasonably expected to cause the failure of

the life support device or system, or to affect its

safety or effectiveness.

National Semiconductor

Corporation

Americas

Tel: 1-800-272-9959

Fax: 1-800-737-7018

Email: support@nsc.com

National Semiconductor

Europe

National Semiconductor

Asia Pacific Customer

Response Group

Tel: 65-2544466

Fax: 65-2504466

National Semiconductor

Japan Ltd.

Tel: 81-3-5639-7560

Fax: 81-3-5639-7507

Fax: +49 (0) 180-530 85 86

Email: europe.support@nsc.com

Deutsch Tel: +49 (0) 69 9508 6208

English Tel: +44 (0) 870 24 0 2171

Français Tel: +33 (0) 1 41 91 8790

Email: ap.support@nsc.com

www.national.com

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.


型号：	LM4051
厂家：	National Semiconductor
描述：	Precision Micropower Shunt Voltage Reference 精密微功耗并联型电压基准
文件：	总14页 (文件大小：304K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

LM4051 [NSC]

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