MAX4173TEUT+T - Maxim - Datasheet.Directory

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Functional Diagrams

Pin Configurations appear at end of data sheet.

Functional Diagrams continued at end of data sheet.

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For pricing, delivery, and ordering information, please contact Maxim Direct

at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.

General Description

The MAX4173 low-cost, precision, high-side current-

sense amplifier is available in a tiny SOT23-6 package.

It features a voltage output that eliminates the need for

gain-setting resistors and it is ideal for today’s notebook

computers, cell phones, and other systems where cur-

rent monitoring is critical. High-side current monitoring

is especially useful in battery-powered systems, since it

does not interfere with the ground path of the battery

charger. The input common-mode range of 0 to +28V is

independent of the supply voltage and ensures that the

current-sense feedback remains viable even when con-

nected to a battery in deep discharge. The MAX4173’s

wide 1.7MHz bandwidth makes it suitable for use inside

battery charger control loops.

The combination of three gain versions and a user-

selectable external sense resistor sets the full-scale

current reading. This feature offers a high level of inte-

gration, resulting in a simple and compact current-

sense solution.

The MAX4173 operates from a single +3V to +28V sup-

ply, typically draws only 420µA of supply current over

the extended operating temperature range (-40°C to

+85°C), and is offered in the space-saving SOT23

package.

Applications

Notebook Computers

Portable/Battery-Powered Systems

Smart Battery Packs/Chargers

Cell Phones

Power-Management Systems

General System/Board-Level Current Monitoring

PA Bias Control

Precision Current Sources

Features

oLow-Cost, Compact Current-Sense Solution

oHigh Accuracy +2V to +28V Common-Mode

Range, Functional Down to 0V, Independent of

Supply Voltage

oThree Gain Versions Available

+20V/V (MAX4173T)

+50V/V (MAX4173F)

+100V/V (MAX4173H)

o±0.5% Full-Scale Accuracy

o±3mV Input Offset Voltage (MAX4173T)

oWide 1.7MHz Bandwidth (MAX4173T)

o420µA Supply Current

oAvailable in Space-Saving SOT23 Package

Low-Cost, SOT23, Voltage-Output,

High-Side Current-Sense Amplifier

MAX4173T/F/H

RSENSE

0 TO +28V ILOAD

VSENSE

VCC

OUT

GND

RS+

+3V TO +28V RS-

LOAD/

BATTERY

A/D

CONVERTER

0.1µF

Typical Operating Circuit

PART

MAX4173TEUT+T

MAX4173TESA+

PIN-PACKAGE

6 SOT23

8 SO

Ordering Information

-40°C to +85°C

TEMP RANGE SOT TOP MARK

AABN

—

MAX4173FEUT+T -40°C to +85°C 6 SOT23 AABO

MAX4173FESA+ -40°C to +85°C 8 SO —

MAX4173HEUT+T -40°C to +85°C 6 SOT23 AABP

MAX4173HESA+ -40°C to +85°C 8 SO —

GAIN (V/V)

100

Pin Configurations appear at end of data sheet.

Denotes a lead(Pb)-free/RoHS-compliant package.

= Tape and reel.

MAX4173

19-1434; Rev 5; 4/11

Low-Cost, SOT23, Voltage-Output,

High-Side Current-Sense Amplifier

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VRS+ = 0 to +28V, VCC = +3V to +28V, VSENSE = 0V, TA = TMIN to TMAX, RLOAD = ∞unless otherwise noted. Typical values are at

TA = +25°C.) (Note 1)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional

operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to

absolute maximum rating conditions for extended periods may affect device reliability.

VCC, RS+, RS- to GND .......................................... -0.3V to +30V

OUT to GND .............................................. -0.3V to (VCC + 0.3V)

Output Short-Circuit to VCC or GND ......................... Continuous

Differential Input Voltage (VRS+ - VRS-) ............................. ±0.3V

Current into Any Pin......................................................... ±20mA

Continuous Power Dissipation (TA= +70°C)

8-Pin SO (derate 5.88mW/°C above +70°C)............... 471mW

SOT23-6 (derate 8.7mW/°C above +70°C)................. 696mW

Operating Temperature Range .......................... -40°C to +85°C

Storage Temperature Range ............................ -65°C to +150°C

Lead Temperature (soldering, 10s) ................................ +300°C

Soldering Temperature (reflow) ...................................... +260°C

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Operating Voltage Range VCC Guaranteed by PSR test 3 28 V

Common-Mode Input Range VCMR (Note 2) 0 28 V

Common-Mode Rejection CMR VRS+ > +2.0V 90 dB

Supply Current ICC VRS+ > +2.0V, VCC > 12V 0.42 1.0 mA

Leakage Current IRS+, IRS- VCC = 0V, VRS+ = 28V 0.3 3 µA

VRS+ > +2.0V 0 50

IRS+ VRS+ ≤ +2.0V -350 50

VRS+ > +2.0V 0 100

Input Bias Current

IRS- VRS+ ≤ +2.0V -700 100

µA

Full-Scale Sense Voltage VSENSE VSENSE = VRS+ - VRS- 150 mV

VSENSE = +100mV, VCC = +12V, VRS+ = +12V ±0.5 5.75

VSENSE = +100mV, VCC = +12V, VRS+ = +12V,

TA = +25°C 0.5 3.25

VSENSE = +100mV, VCC = +28V, VRS+ = +28V 0.5 5.75

VSENSE = +100mV, VCC = +12V, VRS+ = +0.1V -9 ±24

Total OUT Voltage Error

(Note 3)

VCC = +12V, VRS+ = +12V, VSENSE = +6.25mV

(Note 4) ±7.5

MAX4173T, VCC = +3.0V, VRS+ = 28V,

VSENSE = 250mV 0.8 1.2

MAX4173F, VCC = +7.5V, VRS+ = 28V,

VSENSE = 250mV 0.8 1.2

Out High Voltage (Note 5) (VCC - VOH)

MAX4173H, VCC = +15V, VRS+ = 28V,

VSENSE = 250mV 0.8 1.2

TA = +25°C 1.2 5

OUT Low Voltage VOL

MAX4173TEUT,

VCC = +5V, VRS+ = 0.89V,

VSENSE = 0mV TA = -40°C to +85°C 40

Maxim Integrated

MAX4173

Low-Cost, SOT23, Voltage-Output,

High-Side Current-Sense Amplifier

Note 1: All devices are 100% production tested at TA = +25°C. All temperature limits are guaranteed by design.

Note 2: Guaranteed by Total Output Voltage Error Test.

Note 3: Total OUT Voltage Error is the sum of gain and offset voltage errors.

Note 4: +6.25mV = 1/16 of +100mV full-scale voltage.

Note 5: VSENSE such that output stage is in saturation.

Note 6: VOS is extrapolated from the Gain Accuracy tests.

Note 7: The device does not experience phase reversal when overdriven.

ELECTRICAL CHARACTERISTICS (continued)

(VRS+ = 0 to +28V, VCC = +3V to +28V, VSENSE = 0V, TA = TMIN to TMAX, RLOAD = ∞unless otherwise noted. Typical values are at

TA = +25°C.) (Note 1)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

MAX4173T,

VSENSE = +100mV 1.7

MAX4173F,

VSENSE = +100mV 1.4

MAX4173H,

VSENSE = +100mV 1.2

Bandwidth BW

VRS+ = +12V,

VCC = +12V,

CLOAD = 5pF

VSENSE = +6.25mV

(Note 4) 0.6

MHz

MAX4173T 20

MAX4173F 50Gain AV

MAX4173H 100

V/V

TA = +25°C 0.5 ±2.5

∆AV

MAX4173T/F VSENSE =

+10mV to +150mV,

VCC = VRS+ = 12V TA = -40°C to +85°C 4.0

TA = +25°C 0.5 ±2.5

Gain Accuracy

∆AV

MAX4173H VSENSE =

+10mV to +100mV,

VCC = VRS+ = 12V TA = -40°C to +85°C 4.0

TA = +25°C 0.3 ±3

Input Offset Voltage

(Note 6) VOS MAX4173TEUT,

VRS+ = 12V TA = -40°C to +85°C ±5 mV

VSENSE = +6.25mV

to +100mV 400

OUT Settling Time to 1% of

Final Value

VCC = +12V, VRS+ = 12V,

CLOAD = 5pF VSENSE = +100mV

to +6.25mV 800

OUT Output Resistance ROUT 12 kΩ

MAX4173T, VSENSE = 80mV, VRS+ ≥ +2V 60 84

MAX4173F, VSENSE = 32mV, VRS+ ≥ +2V 60 91

Power-Supply Rejection PSR

MAX4173H, VSENSE = 16mV, VRS+ ≥ +2V 60 95

Power-Up Time to 1% of

Final Value VSENSE = +100mV, CLOAD = 5pF 10 µs

Saturation Recovery Time VCC = +12V, VRS+ = 12V (Note 7) 10 µs

Maxim Integrated

MAX4173

Low-Cost, SOT23, Voltage-Output,

High-Side Current-Sense Amplifier

370

390

380

410

400

430

420

440

010155 202530

SUPPLY CURRENT vs. SUPPLY VOLTAGE

MAX4173 TOC01

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (µA)

MAX4173T

MAX4173F

MAX4173H

200

300

250

450

400

350

550

500

150

-50 -5 10-35-20 2540557085

SUPPLY CURRENT vs. TEMPERATURE

MAX4173 toc02

TEMPERATURE (°C)

SUPPLY CURRENT (µA)

MAX4173T

MAX4173F

MAX4173H

0.4

0.2

0.8

0.6

1.2

1.0

1.4

0 1.0 1.50.5 2.0 2.5 28

SUPPLY CURRENT vs. RS+ VOLTAGE

MAX4173 toc03

VRS+ (V)

SUPPLY CURRENT (mA)

MAX4173T

MAX4173H

MAX4173F

-0.60

-0.45

-0.30

-0.15

0.15

0.30

0.45

0.60

0105 15202530

TOTAL OUTPUT ERROR vs.

SUPPLY VOLTAGE

MAX4173 toc04

SUPPLY VOLTAGE (V)

TOTAL OUTPUT ERROR (%)

MAX4173F

VSENSE = 100mV

MAX4173T

MAX4173H

-100

100 1k 10k 100k 1M 10M

POWER-SUPPLY REJECTION

vs. FREQUENCY

-80

MAX4173 toc07

FREQUENCY (Hz)

PSR (dB)

-60

-40

-20

-10

-90

-70

-50

-30

-6

-2

-4

010155 202530

TOTAL OUTPUT ERROR

vs. SUPPLY VOLTAGE

MAX4173 toc05

SUPPLY VOLTAGE (V)

TOTAL OUTPUT ERROR (%)

MAX4173F

VSENSE = 6.25mV

MAX4173H

MAX4173T

-2

-1

0 10050 150 200

TOTAL OUTPUT ERROR vs.

FULL-SCALE SENSE VOLTAGE

MAX4173 toc06

VSENSE (mV)

TOTAL OUTPUT ERROR (%)

MAX4173F

VCC = 28V

MAX4173H

MAX4173T

-10

-8

-6

-4

-2

0105 15202530

TOTAL OUTPUT ERROR vs.

COMMON-MODE VOLTAGE

MAX4173 toc08

COMMON-MODE VOLTAGE (V)

TOTAL OUTPUT ERROR (%)

MAX4173F

MAX4173TMAX4173H

Typical Operating Characteristics

(VCC = +12V, VRS+ = +12V, VSENSE = +100mV, TA= +25°C, unless otherwise noted.)

-1.2

-0.4

-0.8

0.4

0.8

1.2

-50 -20 -5 10-35 2540557085

GAIN ACCURACY vs. TEMPERATURE

MAX4173 toc09

TEMPERATURE (°C)

GAIN ACCURACY (%)

MAX4173F

MAX4173H

MAX4173T

Maxim Integrated

MAX4173

Low-Cost, SOT23, Voltage-Output,

High-Side Current-Sense Amplifier

Typical Operating Characteristics (continued)

(VCC = +12V, VRS+ = +12V, VSENSE = +100mV, TA= +25°C, unless otherwise noted.)

-2.0

-1.0

-1.5

0.5

-0.5

1.5

1.0

2.0

-50 -5 10-35 -20 25 40 55 70 85

TOTAL OUTPUT ERROR

vs. TEMPERATURE

MAX4173 toc10

TEMPERATURE (°C)

TOTAL OUTPUT ERROR (%)

MAX4173H

MAX4173T

MAX4173F

2µs/div

MAX4173T

LARGE-SIGNAL TRANSIENT RESPONSE

(VSENSE = 6mV to 100mV)

(45mV/div)

OUT

(500mV/div)

6mV

100mV

0.120V

MAX4173 toc11

CL = 5pF

2µs/div

MAX4173F

LARGE-SIGNAL TRANSIENT RESPONSE

(VSENSE = 6mV to 100mV)

(45mV/div)

OUT

(2V/div)

6mV

100mV

0.3V

MAX4173 toc12

CL = 5pF

2µs/div

MAX4173H

LARGE-SIGNAL TRANSIENT RESPONSE

(VSENSE = 6mV to 100mV)

(45mV/div)

OUT

(3V/div)

6mV

100mV

10V

0.6V

MAX4173 toc13

CL = 5pF

2µs/div

MAX4173T

SMALL-SIGNAL TRANSIENT RESPONSE

(VSENSE = 95mV TO 100mV)

(5mV/div)

OUT

(50mV/div)

95mV

100mV

2.0V

1.9V

MAX4173 toc14

CL = 5pF

2µs/div

MAX4173F

SMALL-SIGNAL TRANSIENT RESPONSE

(VSENSE = 95mV TO 100mV)

(5mV/div)

OUT

(100mV/div)

95mV

100mV

4.75V

MAX4173 toc16

CL = 5pF

Maxim Integrated

MAX4173

Low-Cost, SOT23, Voltage-Output,

High-Side Current-Sense Amplifier

Pin Description

Typical Operating Characteristics (continued)

(VCC = +12V, VRS+ = +12V, VSENSE = +100mV, TA= +25°C, unless otherwise noted.)

2µs/div

MAX4173H

SMALL-SIGNAL TRANSIENT RESPONSE

(VSENSE = 95mV to 100mV)

(5mV/div)

OUT

(200mV/div)

95mV

100mV

10V

9.5V

MAX4173 toc15

CL = 5pF

5µs/div

START-UP DELAY (VCC = 0 to 4V)

(VSENSE = 100mV)

(2V/div)

OUT

(1V/div)

MAX4173 toc17

6Load-Side Connection for the External Sense ResistorRS-5

FUNCTIONNAME

SOT23

1Supply Voltage Input. Bypass to GND with a 0.1µF capacitor.VCC

4Voltage Output. VOUT is proportional to VSENSE ( VRS+ - VRS- ). Output impedance is

approximately 12kΩ.

OUT6

3GroundGND1, 2

8Power-Side Connection to the External Sense ResistorRS+4

2, 5, 7 No Connection. Not internally connected.N.C.–

Maxim Integrated

MAX4173

Low-Cost, SOT23, Voltage-Output,

High-Side Current-Sense Amplifier

Detailed Description

The MAX4173 high-side current-sense amplifier fea-

tures a 0 to +28V input common-mode range that is

independent of supply voltage. This feature allows the

monitoring of current out of a battery in deep discharge

and also enables high-side current sensing at voltages

greater than the supply voltage (VCC).

The MAX4173 operates as follows: Current from the

source flows through RSENSE to the load (Figure 1). Since

the internal-sense amplifier’s inverting input has high

impedance, negligible current flows through RG2

(neglecting the input bias current). Therefore, the

sense amplifier’s inverting-input voltage equals

VSOURCE - (ILOAD)(RSENSE). The amplifier’s open-loop

gain forces its noninverting input to the same voltage as

the inverting input. Therefore, the drop across RG1

equals (ILOAD)(RSENSE). Since IRG1 flows through RG1,

IRG1 = (ILOAD)(RSENSE) / RG1. The internal current mirror

multiplies IRG1 by a current gain factor, β, to give

IRGD = β·IRG1. Solving IRGD = β·(ILOAD)(RSENSE) /

RG1. Assuming infinite output impedance, VOUT = (IRGD)

(RGD). Substituting in for IRGD and rearranging, VOUT =

β·(RGD / RG1)(RSENSE ·ILOAD). The parts gain equals

β·RGD / RG1. Therefore, VOUT = (GAIN) (RSENSE)

(ILOAD), where GAIN = 20 for MAX4173T, GAIN = 50 for

MAX4173F, and GAIN = 100 for MAX4173H.

Set the full-scale output range by selecting RSENSE and

the appropriate gain version of the MAX4173.

Applications Information

Recommended Component Values

The MAX4173 senses a wide variety of currents with

different sense resistor values. Table 1 lists common

resistor values for typical operation of the MAX4173.

Choosing RSENSE

To measure lower currents more accurately, use a high

value for RSENSE. The high value develops a higher

sense voltage that reduces offset voltage errors of the

internal op amp.

In applications monitoring very high currents, RSENSE

must be able to dissipate the I2R losses. If the resistor’s

rated power dissipation is exceeded, its value may drift

or it may fail altogether, causing a differential voltage

across the terminals in excess of the absolute maxi-

mum ratings.

If ISENSE has a large high-frequency component, mini-

mize the inductance of RSENSE. Wire-wound resistors

have the highest inductance, metal-film resistors are

somewhat better, and low-inductance metal-film resis-

tors are best suited for these applications.

Using a PCB Trace as RSENSE

If the cost of RSENSE is an issue and accuracy is not

critical, use the alternative solution shown in Figure 2.

This solution uses copper PC board traces to create a

sense resistor. The resistivity of a 0.1-inch-wide trace of

2-ounce copper is approximately 30mΩ/ft. The resis-

tance-temperature coefficient of copper is fairly high

(approximately 0.4%/°C), so systems that experience a

wide temperature variance must compensate for this

effect. In addition, do not exceed the maximum power

dissipation of the copper trace.

For example, the MAX4173T (with a maximum load cur-

rent of 10A and an RSENSE of 5mΩ) creates a full-scale

VSENSE of 50mV that yields a maximum VOUT of 1V.

RSENSE in this case requires about 2 inches of 0.1 inch-

wide copper trace.

Output Impedance

The output of the MAX4173 is a current source driving a

12kΩresistance. Resistive loading added to OUT

reduces the output gain of the MAX4173. To minimize

output errors for most applications, connect OUT to a

high-impedance input stage. When output buffering is

required, choose an op amp with a common-mode

input range and an output voltage swing that includes

ground when operating with a single supply. The op

RSENSE

VSOURCE

0 TO +28V

+3V TO +28V

RGD = 12k

VOUT

IRG1

IRGD

ILOAD

RG1 RG2

RS-RS+

OUT

GND

TO LOAD BATTERY

VCC

CURRENT

MIRROR

MAX4173

Figure 1. Functional Diagram

Maxim Integrated

MAX4173

Low-Cost, SOT23, Voltage-Output,

High-Side Current-Sense Amplifier

amp’s supply voltage range should be at least as high

as any voltage the system may encounter.

The percent error introduced by output loading is

determined with the following formula:

where RLOAD is the external load applied to OUT.

Current Source Circuit

Figure 3 shows a block diagram using the MAX4173

with a switching regulator to make a current source.

% 100 R

12k R

ERROR LOAD

LOAD

=Ω+ −

⎛

⎝

⎜⎞

⎠

⎟

Table 1. Recommended Component Values

MAX4173T

VSENSE

RSENSE

+3V TO +28V

0.1µF

RS+

0.3 in. COPPER

INPUT LOAD/BATTERY

0.3 in. COPPER0.1 in. COPPER

RS-

GND

OUT

VCC

Figure 2. MAX4173 Connections Showing Use of PC Board Figure 3. Current Source

MAX4173

RSENSE

ILOAD

0 TO +28V VSENSE

VCC

OUT

VIN

GND

RS+

+3V TO +28V

0.1µF

RS-

LOAD/

BATTERY

LOW-COST

SWITCHING

REGULATOR

10.0100

5.050

2.0

10 10

10.0100

5.050

2.0

520

10.0100

5.050

2.0

1100

10.0100

5.0501000

CURRENT-SENSE RESISTOR

RSENSE (mΩΩ)

GAIN

2.0

0.1

FULL-SCALE OUTPUT VOLTAGE

(FULL-SCALE VSENSE = 100mV)

VOUT (V)

FULL-SCALE LOAD CURRENT

ILOAD (A)

Maxim Integrated

MAX4173

RS-

N.C.OUT

RS+

N.C.N.C.

GND

VCC

MAX4173

Pin Configurations

Low-Cost, SOT23, Voltage-Output,

High-Side Current-Sense Amplifier

5 RS-

GND

RS+VCC

6 OUT

MAX4173

SOT23

TOP VIEW

PACKAGE

TYPE

PACKAGE

CODE

OUTLINE

NO.

LAND

PATTERN NO.

8 SO S8+4 21-0041 90-0096

6 SOT23 U6+2 21-0058 90-0175

Package Information

For the latest package outline information and land patterns

(footprints), go to www.maxim-ic.com/packages. Note that a

“+”, “#”, or “-” in the package code indicates RoHS status only.

Package drawings may show a different suffix character, but

the drawing pertains to the package regardless of RoHS status.

Maxim Integrated

MAX4173

Low-Cost, SOT23, Voltage-Output,

High-Side Current-Sense Amplifier

Revision History

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

4 6/10 Clarified 0V to 2V is not a high-accuracy range for the device, added lead-free

options and soldering temperature 1, 2

5 4/11 Updated VRS+ conditions to synchronize with tested material 2, 3

MAX4173

10 Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.

Maxim reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical

Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.