LM4125IM5-2.0 - National Semiconductor

LM4125

Precision Micropower Low Dropout Voltage Reference

General Description

The LM4125 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 6V consuming 160 µA (Typ.) supply current. In

power down mode, device current drops to less than 2 µA.

The LM4125 comes in two grades (A and Standard) and

three 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 −40˚C to +125˚C.

The very low dropout voltage, low supply current and power-

down capability of the LM4125 makes this product an ideal

choice for battery powered and portable applications.

The device performance is guaranteed over the industrial

temperature range (−40˚C to +85˚C), while certain specs are

guaranteed over the extended temperature range (−40˚C to

+125˚C). Please contact National for full specifications over

the extended temperature range. The LM4125 is available in

a standard 5-pin SOT-23 package.

Features

nSmall SOT23-5 package

nLow dropout voltage: 120 mV Typ @1mA

nHigh output voltage accuracy: 0.2%

nSource and Sink current output: ±5mA

nSupply current: 160 µA Typ.

nLow Temperature Coefficient: 50 ppm/˚C

nFixed output voltages: 2.048, 2.5,and 4.096

nIndustrial temperature Range: −40˚C to +85˚C

n(For extended temperature range, −40˚C to 125˚C,

contact National Semiconductor)

Applications

nPortable, battery powered equipment

nInstrumentation and process control

nAutomotive & Industrial

nTest equipment

nData acquisition systems

nPrecision regulators

nBattery chargers

nBase stations

nCommunications

nMedical equipment

Connection Diagram

20069802

Refer to the Ordering Information Table in this Data Sheet for Specific Part Number

SOT23-5 Surface Mount Package

November 2003

LM4125 Precision Micropower Low Dropout Voltage Reference

Ordering Information

Industrial Temperature Range (−40˚C to + 85˚C)

Initial Output Voltage Accuracy at 25˚C

And Temperature Coefficient

LM4125 Supplied as

1000 Units, Tape and

Reel

LM4125 Supplied as

3000 Units, Tape and

Reel

Top

Marking

0.2%, 50 ppm/˚C max (A grade)

LM4125AIM5-2.0 LM4125AIM5X-2.0 R80A

LM4125AIM5-2.5 LM4125AIM5X-2.5 R81A

LM4125AIM5-4.1 LM4125AIM5X-4.1 R82A

0.5%, 50 ppm/˚C max

LM4125IM5-2.0 LM4125IM5X-2.0 R80B

LM4125IM5-2.5 LM4125IM5X-2.5 R81B

LM4125IM5-4.1 LM4125IM5X-4.1 R82B

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:

80 = 2.048V Voltage Option

81 = 2.500V Voltage Option

82 = 4.096V Voltage Option

Fourth Field:

A-B = Initial Reference Voltage Tolerance

A=±0.2%

B=±0.5%

LM4125

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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 8V

Output Short-Circuit Duration Indefinite

Power Dissipation (T

= 25˚C) (Note 2):

MA05B package − θ

280˚C/W

Power Dissipation 350 mW

ESD Susceptibility (Note 3)

Human Body Model

Machine Model

2kV

200V

Lead Temperature:

Soldering, (10 sec.) +260˚C

Vapor Phase (60 sec.) +215˚C

Infrared (15 sec.) +220˚C

Operating Range (Note 1)

Storage Temperature

Range −65˚C to +150˚C

Ambient Temperature

Range −40˚C to +85˚C

Junction Temperature

Range −40˚C to +125˚C

Electrical Characteristics

LM4125-2.048V and 2.5V Unless otherwise specified V

= 3.3V, I

LOAD

=0,C

OUT

= 0.01µF, T

= 25˚C.

Limits with standard typeface are for T

= 25˚C, and limits in boldface type apply over the −40˚C ≤T

≤+85˚C temperature

range.

Symbol Parameter Conditions Min

(Note 5)

Typ

(Note 4)

Max

(Note 5) Units

OUT

Output Voltage Initial

Accuracy

LM4125A-2.048

LM4125A-2.500

±0.2 %

LM4125-2.048

LM4125-2.500 ±0.5 %

TCV

OUT

/˚C Temperature

Coefficient

−40˚C ≤T

≤+125˚C 14 50 ppm/˚c

∆V

OUT

/∆V

Line Regulation 3.3V ≤V

≤6V 0.0007 0.008

0.01 %/V

∆V

OUT

/∆I

LOAD

Load Regulation

0mA≤I

LOAD

≤1 mA 0.03 0.08

0.17

%/mA

1mA≤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

OUT

Dropout Voltage

(Note 6)

LOAD

=0mA 45 65

100

LOAD

= +1 mA 120 150

200

LOAD

= +5 mA 180 210

300

Output Noise Voltage

(Note 8)

0.1 Hz to 10 Hz 20 µV

10 Hz to 10 kHz 36 µV

Supply Current 160 257

290

µA

Short Circuit Current

= 3.3V, V

OUT

=0 15

630

= 6V, V

OUT

=0 17

630

Hyst Thermal Hysteresis

(Note 7)

−40˚C ≤T

≤125˚C 0.5 mV/V

LM4125

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Electrical Characteristics

LM4125-2.048V and 2.5V Unless otherwise specified V

= 3.3V, I

LOAD

=0,C

OUT

= 0.01µF, T

= 25˚C.

Limits with standard typeface are for T

= 25˚C, and limits in boldface type apply over the −40˚C ≤T

≤+85˚C temperature

range. (Continued)

Symbol Parameter Conditions Min

(Note 5)

Typ

(Note 4)

Max

(Note 5) Units

∆V

OUT

Long Term Stability

(Note 9)

1000 hrs. @25˚C 100 ppm

Electrical Characteristics

LM4125-4.096V

Unless otherwise specified V

= 5V, I

LOAD

=0,C

OUT

= 0.01µF, T

= 25˚C. Limits with standard typeface are for T

25˚C, and limits in boldface type apply over the −40˚C ≤T

≤+85˚C temperature range.

Symbol Parameter Conditions Min (Note 5) Typ (Note

Max (Note

5) Units

OUT

Output Voltage Initial

Accuracy

LM4125A-4.096

±0.2 %

LM4125-4.096 ±0.5 %

TCV

OUT

/˚C Temperature

Coefficient

−40˚C ≤T

≤+125˚C 14 50 ppm/˚c

∆V

OUT

/∆V

Line Regulation 5V ≤V

≤6V 0.0007 0.008

0.01 %/V

∆V

OUT

/∆I

LOAD

Load Regulation

0mA≤I

LOAD

≤1 mA 0.03 0.08

0.17

%/mA

1mA≤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

OUT

Dropout Voltage

(Note 6)

LOAD

=0mA 45 65

100

LOAD

= +1 mA 120 150

200

LOAD

= +5 mA 180 210

300

Output Noise Voltage

(Note 8)

0.1 Hz to 10 Hz 20 µV

10 Hz to 10 kHz 36 µV

Supply Current 160 257

290

µA

Short Circuit Current

OUT

=0 15

630

= 6V, V

OUT

=0 17

630

Hyst Thermal Hysteresis

(Note 7)

−40˚C ≤T

≤125˚C 0.5 mV/V

∆V

OUT

Long Term Stability

(Note 9)

1000 hrs. @25˚C 100 ppm

LM4125

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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

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: 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

=(T

JMAX −T

A)/θJ-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 kΩresistor into each pin. The machine model is a 200 pF capacitor discharged

directly into each pin.

Note 4: Typical numbers are at 25˚C and represent the most likely parametric norm.

Note 5: Limits are 100% production tested at 25˚C. 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 VOUT and VIN at which VOUT changes ≤1% from VOUT at VIN = 3.3V for 2.0V, 2.5V and 5V for 4.1V. A

parasitic diode exists between input and output pins; it will conduct if VOUT is pulled to a higher voltage than VIN.

Note 7: Thermal hysteresis is defined as the change in +25˚C output voltage before and after exposing the device to temperature extremes.

Note 8: Output noise voltage is proportional to VOUT.V

Nfor other voltage option is calculated using (VN(1.8V)/1.8) * VOUT.V

N(2.5V) = (36µVPP/1.8) * 2.5 = 46µVPP.

Note 9: Long term stability is change in VREF at 25˚C measured continuously during 1000 hrs.

LM4125

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LM4125 Typical Operating Characteristics

Unless otherwise specified, V

= 3.3V, V

OUT

= 2.5V,

LOAD

=0,C

OUT

= 0.022µF and T

= 25˚C.

Long Term Drift Typical Temperature Drift

20069812 20069813

Short Circuit Current vs Temperature Dropout Voltage vs Output Error

20069814

20069815

Dropout Voltage vs Load Current Load Regulation

20069833 20069818

LM4125

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LM4125 Typical Operating Characteristics Unless otherwise specified, V

= 3.3V, V

OUT

= 2.5V,

ILOAD =0,C

OUT

= 0.022µF and T

= 25˚C. (Continued)

GND Pin Current

GND Pin Current at No Load

vs Temperature

20069819 20069821

GND Pin Current vs Load 0.1Hz to 10Hz output Noise

20069822 20069823

Output Impedance vs Frequency PSRR vs Frequency

20069824 20069825

LM4125

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LM4125 Typical Operating Characteristics Unless otherwise specified, V

= 3.3V, V

OUT

= 2.5V,

ILOAD =0,C

OUT

= 0.022µF and T

= 25˚C. (Continued)

Start-Up Response Load Step Response

20069826 20069828

Load Step Response Line Step Response

20069829 20069830

Thermal Hysteresis

20069831

LM4125

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Pin Functions

Output (Pin 5): Reference Output.

Input (Pin 4):Positive Supply.

Ground (Pin 2):Negative Supply or Ground Connection.

Application Hints

The standard application circuit for the LM4125 is shown in

Figure 1. It is designed to be stable with ceramic output

capacitors in the range of 0.022µF to 0.1µF. Note that

0.022µF is the minimum required output capacitor. These

capacitors typically have an ESR of about 0.1 to 0.5Ω.

Smaller ESR can be tolerated, however larger ESR can not.

The output capacitor can be increased to improve load tran-

sient response, up to about 1µF. However, values above

0.047µF must be tantalum. With tantalum capacitors, in the

1µF range, a small capacitor between the output and the

reference pin is required. This capacitor will typically be in

the 50pF range. Care must be taken when using output

capacitors of 1µF or larger. These application must be thor-

oughly tested over temperature, line and load.

An input capacitor is typically not required. However, a 0.1µF

ceramic can be used to help prevent line transients from

entering the LM4125. Larger input capacitors should be

tantalum or aluminium.

The typical thermal hysteresis specification is defined as the

change in +25˚C voltage measured after thermal cycling.

The device is thermal cycled to temperature -40˚C and then

measured at 25˚C. Next the device is thermal cycled to

temperature +125˚C and again measured at 25˚C. The re-

sulting V

OUT

delta shift between the 25˚C measurements is

thermal hysteresis. Thermal hysteresis is common in preci-

sion references and is induced by thermal-mechanical pack-

age stress. Changes in environmental storage temperature,

operating temperature and board mounting temperature are

all factors that can contribute to thermal hysteresis.

INPUT CAPACITOR

Noise on the power-supply input can effect the output noise,

but can be reduced by using an optional bypass capacitor

between the input pin and the ground.

PRINTED CIRCUIT BOARD LAYOUT CONSIDERATION

The mechanical stress due to PC board mounting can cause

the output voltage to shift from its initial value. References in

SOT packages are generally less prone to assembly stress

than devices in Small Outline (SOIC) package.

To reduce the stress-related output voltage shifts, mount the

reference on the low flex areas of the PC board such as near

to the edge or the corner of the PC board.

20069832

FIGURE 1.

LM4125

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Typical Application Circuits

Voltage Reference with Negative Output

20069803

Precision High Current Low Dropout Regulator

20069804

Precision High Current

Negative Voltage Regulator

20069805

Voltage Reference with Complimentary Output

20069806

Precision High Current Low Droput Regulator

20069807

Precision Voltage Reference

with Force and Sense Output

20069809

Programmable Current Source

20069810

LM4125

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Typical Application Circuits

(Continued)

Precision Regulator with Current Limiting Circuit

20069811

Power Supply Splitter

20069820

LM4125

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Physical Dimensions inches (millimeters)

unless otherwise noted

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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.

BANNED SUBSTANCE COMPLIANCE

National Semiconductor certifies that the products and packing materials meet the provisions of the Customer Products

Stewardship Specification (CSP-9-111C2) and the Banned Substances and Materials of Interest Specification

(CSP-9-111S2) and contain no ‘‘Banned Substances’’ as defined in CSP-9-111S2.

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www.national.com

LM4125 Precision Micropower Low Dropout Voltage Reference

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.