Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsLinear ICsLinear IC - Op-amp Current sensor uMAX 8

AVAILABLE

EVALUATION KIT AVAILABLE

Functional Diagrams

Pin Configurations appear at end of data sheet.

Functional Diagrams continued at end of data sheet.

UCSP is a trademark of Maxim Integrated Products, Inc.

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 MAX4080/MAX4081 are high-side, current-sense

amplifiers with an input voltage range that extends from

4.5V to 76V making them ideal for telecom, automotive,

backplane, and other systems where high-voltage cur-

rent monitoring is critical. The MAX4080 is designed for

unidirectional current-sense applications and the

MAX4081 allows bidirectional current sensing. The

MAX4081 single output pin continuously monitors the

transition from charge to discharge and avoids the

need for a separate polarity output. The MAX4081

requires an external reference to set the zero-current

output level (V

SENSE

= 0V). The charging current is rep-

resented by an output voltage from V

REF

to V

, while

discharge current is given from V

REF

to GND.

For maximum versatility, the 76V input voltage range

applies independently to both supply voltage (V

)

and common-mode input voltage (V

RS+

). High-side

current monitoring does not interfere with the ground

path of the load being measured, making the

MAX4080/MAX4081 particularly useful in a wide range

of high-voltage systems.

The combination of three gain versions (5V/V, 20V/V,

60V/V = F, T, S suffix) and a user-selectable, external

sense resistor sets the full-scale current reading and its

proportional output voltage. The MAX4080/MAX4081

offer a high level of integration, resulting in a simple,

accurate, and compact current-sense solution.

The MAX4080/MAX4081 operate from a 4.5V to 76V sin-

gle supply and draw only 75µA of supply current. These

devices are specified over the automotive operating

temperature range (-40°C to +125°C) and are available

in a space-saving 8-pin µMAX

or SO package.

Applications

Automotive (12V, 24V, or 42V Batteries)

48V Telecom and Backplane Current

Measurement

Bidirectional Motor Control

Power-Management Systems

Avalanche Photodiode and PIN-Diode Current

Monitoring

General System/Board-Level Current Sensing

Precision High-Voltage Current Sources

Features

o Wide 4.5V to 76V Input Common-Mode Range

o Bidirectional or Unidirectional I

SENSE

o Low-Cost, Compact, Current-Sense Solution

o Three Gain Versions Available

5V/V (MAX4080F/MAX4081F)

20V/V (MAX4080T/MAX4081T)

60V/V (MAX4080S/MAX4081S)

o ±0.1% Full-Scale Accuracy

o Low 100µV Input Offset Voltage

o Independent Operating Supply Voltage

o 75µA Supply Current (MAX4080)

o Reference Input for Bidirectional OUT (MAX4081)

o Available in a Space-Saving, 8-Pin µMAX Package

76V, High-Side, Current-Sense Amplifiers with

Voltage Output

N.C.

OUTGND

RS-

N.C.V

N.C.

RS+

µMAX/SO

TOP VIEW

MAX4080

REF1B

OUTGND

RS-

REF1AV

N.C.

RS+

µMAX/SO

MAX4081

Pin Configurations

Ordering Information

PART TEMP RANGE PIN-PACKAGE

MAX4080FAUA+ -40°C to +125°C 8 µMAX

MAX4080FAUA/V+ -40°C to +125°C 8 µMAX

MAX4080FASA+ -40°C to +125°C 8 SO

MAX4080TAUA+ -40°C to +125°C 8 µMAX

MAX4080TAUA/V+ -40°C to +125°C 8 µMAX

MAX4080TASA+ -40°C to +125°C 8 SO

MAX4080SAUA+ -40°C to +125°C 8 µMAX

MAX4080SAUA/V+ -40°C to +125°C 8 µMAX

MAX4080SASA+ -40°C to +125°C 8 SO

Selector Guide appears at end of data sheet.

Ordering Information continued at end of data sheet.

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

/V denotes an automotive qualified part.

µMAX is a registered trademark of Maxim Integrated Products, Inc.

Ordering Information

19-2562; Rev 4; 7/11

MAX4080/MAX4081

Summary of content (14 pages)

PAGE 1
EVALUATION KIT AVAILABLE MAX4080/MAX4081 76V, High-Side, Current-Sense Amplifiers with Voltage Output LE AVAILAB General Description The MAX4080/MAX4081 are high-side, current-sense amplifiers with an input voltage range that extends from 4.5V to 76V making them ideal for telecom, automotive, backplane, and other systems where high-voltage current monitoring is critical. The MAX4080 is designed for unidirectional current-sense applications and the MAX4081 allows bidirectional current sensing.
PAGE 2
MAX4080/MAX4081 76V, High-Side, Current-Sense Amplifiers with Voltage Output ABSOLUTE MAXIMUM RATINGS VCC to GND ............................................................-0.3V to +80V RS+, RS- to GND....................................................-0.3V to +80V OUT to GND.............-0.3V to the lesser of +18V or (VCC + 0.3V) REF1A, REF1B to GND (MAX4081 Only)....-0.3V to the lesser of +18V or (VCC + 0.3V) Output Short Circuit to GND.......................................
PAGE 3
MAX4080/MAX4081 76V, High-Side, Current-Sense Amplifiers with Voltage Output DC ELECTRICAL CHARACTERISTICS (continued) (VCC = VRS+ = 4.5V to 76V, VREF1A = VREF1B = 5V (MAX4081 only), VSENSE = (VRS+ - VRS-) = 0V, RLOAD = 100kΩ, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Notes 1, 2) PARAMETER OUT Low Voltage REF1A = REF1B Input Voltage Range (MAX4081 Only) SYMBOL CONDITIONS VOL VCC = VRS+ = 48V, VREF1A = VREF1B = IOUT (sinking) = 10µA 2.
PAGE 4
MAX4080/MAX4081 76V, High-Side, Current-Sense Amplifiers with Voltage Output AC ELECTRICAL CHARACTERISTICS (VCC = VRS+ = 4.5V to 76V, VREF1A = VREF1B = 5V (MAX4081 only), VSENSE = (VRS+ - VRS-) = 0V, RLOAD = 100kΩ, CLOAD = 20pF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Notes 1, 2) PARAMETER Bandwidth SYMBOL BW CONDITION VCC = VRS+ = 48V, VOUT = 2.
PAGE 5
MAX4080/MAX4081 76V, High-Side, Current-Sense Amplifiers with Voltage Output Typical Operating Characteristics (VCC = VRS+ = 48V, VSENSE = 0V, CLOAD = 20pF, RLOAD = ∞, TA = +25°C, unless otherwise noted.) INPUT OFFSET VOLTAGE INPUT OFFSET VOLTAGE HISTOGRAM vs. TEMPERATURE GAIN ACCURACY vs. TEMPERATURE 20 15 10 5 50 0 -50 -100 -150 -200 -125 -100 -75 -50 -25 0 25 50 75 100 125 -0.15 F VERSION -0.20 16 28 40 52 64 -0.
PAGE 6
MAX4080/MAX4081 76V, High-Side, Current-Sense Amplifiers with Voltage Output Typical Operating Characteristics (continued) (VCC = VRS+ = 48V, VSENSE = 0V, CLOAD = 20pF, RLOAD = ∞, TA = +25°C, unless otherwise noted.) 75 70 115 115 110 105 100 110 105 95 65 28 40 52 64 76 80 65 4 16 28 40 52 64 -50 76 0 25 50 75 MAX4081 SUPPLY CURRENT vs. TEMPERATURE VOUT HIGH VOLTAGE vs. IOUT (SOURCING) VOUT LOW VOLTAGE vs. IOUT (SINKING) 90 85 80 0.30 0.15 0.
PAGE 7
MAX4080/MAX4081 76V, High-Side, Current-Sense Amplifiers with Voltage Output Typical Operating Characteristics (continued) (VCC = VRS+ = 48V, VSENSE = 0V, CLOAD = 20pF, RLOAD = ∞, TA = +25°C, unless otherwise noted.) MAX4081F SMALL-SIGNAL TRANSIENT RESPONSE MAX4081S SMALL-SIGNAL TRANSIENT RESPONSE MAX4081T SMALL-SIGNAL TRANSIENT RESPONSE MAX4080 toc19 MAX4080 toc21 MAX4080 toc20 INPUT 10mV/div INPUT 2.
PAGE 8
MAX4080/MAX4081 76V, High-Side, Current-Sense Amplifiers with Voltage Output Typical Operating Characteristics (continued) (VCC = VRS+ = 48V, VSENSE = 0V, CLOAD = 20pF, RLOAD = ∞, TA = +25°C, unless otherwise noted.) VCC-TRANSIENT RESPONSE MAX4080 toc28 VCC = 40V VRS+ = 20V VCC = 20V STEP VREF1 = VREF2 = 2.5V MAX4080 toc29 VCC 5V/div INPUT 500mV/div VCC (0 TO 10V) 5V/div OUTPUT 2V/div OUTPUT 2.
PAGE 9
MAX4080/MAX4081 76V, High-Side, Current-Sense Amplifiers with Voltage Output Pin Description PIN NAME FUNCTION MAX4080 MAX4081 1 1 RS+ Power connection to the external-sense resistor. 2 2 VCC Supply Voltage Input. Decouple VCC to GND with at least a 0.1µF capacitor to bypass line transients. 3, 6, 7 3 N.C. No Connection. No internal connection. Leave open or connect to ground. 4 4 GND Ground 5 5 OUT Voltage Output. For the unidirectional MAX4080, VOUT is proportional to VSENSE.
PAGE 10
MAX4080/MAX4081 76V, High-Side, Current-Sense Amplifiers with Voltage Output 10V ILOAD ICHARGE VSENSE RSENSE RS- CHARGE CURRENT SYSTEM LOAD AND CHARGER 5V RS+ VOUT - VREF 4.5V TO 76V BATTERY VOUT = 10V VCC VSENSE MAX4081T REF1A -250mV 250mV 5V REF1B GND -5V VOUT = VGND VREF1A = VREF1B = 5V OUT DISCHARGE CURRENT Figure 1.
PAGE 11
MAX4080/MAX4081 76V, High-Side, Current-Sense Amplifiers with Voltage Output Table 1. Typical Component Values FULL-SCALE LOAD CURRENT, ILOAD (A) CURRENT-SENSE RESISTOR (mΩ) GAIN (V/V) FULL-SCALE VSENSE (mV) MAX4081 FULL-SCALE OUTPUT VOLTAGE (VOUT - VREF, V) 0.500 1000 5 ±500 ±2.5 0.125 1000 20 ±125 ±2.5 0.050 1000 60 ±50 ±3.0 5.000 100 5 ±500 ±2.5 1.250 100 20 ±125 ±2.5 0.500 100 60 ±50 ±3.0 50.000 10 5 ±500 ±2.5 12.500 10 20 ±125 ±2.5 5.000 10 60 ±50 ±3.
PAGE 12
MAX4080/MAX4081 76V, High-Side, Current-Sense Amplifiers with Voltage Output ILOAD = 0 ILOAD = 0 RSENSE RSENSE LOAD RS+ LOAD RS+ RS- VCC RS- VCC REF1A REF1A 10V MAX4081 MAX4081 5V REF1B REF1B GND OUT 5V GND OUT 5V Figure 4. MAX4081 Reference Inputs The full-scale output voltage is VOUT = RSENSE ILOAD (MAX) A V , for the MAX4080 and V OUT = V REF ± R SENSE I LOAD(MAX) A V for the MAX4081.
PAGE 13
MAX4080/MAX4081 76V, High-Side, Current-Sense Amplifiers with Voltage Output Typical Operating Circuit Power Management The bidirectional capability of the MAX4081 makes it an excellent candidate for use in smart battery packs. In the application diagram (Figure 5), the MAX4081 monitors the charging current into the battery as well as the discharge current out of the battery.
PAGE 14
MAX4080/MAX4081 76V, High-Side, Current-Sense Amplifiers with Voltage Output Revision History REVISION NUMBER REVISION DATE 0 10/02 Initial release — 1 11/08 Added values for RG1 and RG2 10 2 5/09 Added lead-free and automotive parts to Ordering Information 3 5/10 Removed automotive part and added soldering temperature 4 7/11 Added automotive part designation DESCRIPTION PAGES CHANGED 1 1, 2 1 Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely emb