MAXIM MAX4080, MAX4081 Technical data

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. 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 VCC, 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

CC

)

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 sin­gle 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

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

♦ Bidirectional or Unidirectional I

SENSE

♦ Low-Cost, Compact, Current-Sense Solution

♦ Three Gain Versions Available

5V/V (MAX4080F/MAX4081F)
20V/V (MAX4080T/MAX4081T)
60V/V (MAX4080S/MAX4081S)

♦ ±0.1% Full-Scale Accuracy

♦ Low 100µV Input Offset Voltage

♦ Independent Operating Supply Voltage

♦ 75µA Supply Current (MAX4080)

♦ Reference Input for Bidirectional OUT (MAX4081)

♦ Available in a Space-Saving 8-Pin µMAX Package

MAX4080/MAX4081

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

Voltage Output

________________________________________________________________ Maxim Integrated Products 1

Pin Configurations

Ordering Information

19-2562; Rev 0; 10/02

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.

EVALUATION KIT

AVAILABLE

Selector Guide appears at end of data sheet.

PART TEMP RANGE PIN-PACKAGE

MAX4080FAUA -40°C to +125°C 8 µMAX

MAX4080FASA -40°C to +125°C 8 SO

MAX4080TAUA -40°C to +125°C 8 µMAX

MAX4080TASA -40°C to +125°C 8 SO

MAX4080SAUA -40°C to +125°C 8 µMAX

MAX4080SASA -40°C to +125°C 8 SO

MAX4081FAUA -40°C to +125°C 8 µMAX

MAX4081FASA -40°C to +125°C 8 SO

MAX4081TAUA -40°C to +125°C 8 µMAX

MAX4081TASA -40°C to +125°C 8 SO

MAX4081SAUA -40°C to +125°C 8 µMAX

MAX4081SASA -40°C to +125°C 8 SO

TOP VIEW

RS+

N.C.

1

2

CC

MAX4080

3

4

87RS-

6

5

N.C.V

N.C.

OUTGND

RS+

N.C.

1

2

CC

MAX4081

3

4

87RS-

REF1AV

REF1B

6

OUTGND

5

μMAX/SO

μMAX/SO

MAX4080/MAX4081

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

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

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.

VCCto GND............................................................-0.3V to +80V

RS+, RS- to GND....................................................-0.3V to +80V

OUT to GND.............-0.3V to the lesser of +18V or (V

CC

+ 0.3V)

REF1A, REF1B to GND

(MAX4081 Only)....-0.3V to the lesser of +18V or (V

CC

+ 0.3V)

Output Short Circuit to GND.......................................Continuous

Differential Input Voltage (V

RS

+ - VRS-)...............................±80V

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

Continuous Power Dissipation (T

A

= +70°C)

8-Pin µMAX (derate 4.5mW/°C above +70°C) .............362mW

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

Operating Temperature Range .........................-40°C to +125°C

Junction Temperature......................................................+150°C

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

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

DC ELECTRICAL CHARACTERISTICS

(VCC= V

RS+

= 4.5V to 76V, V

REF1A

= V

REF1B

= 5V (MAX4081 only), V

SENSE

= (V

RS+

- V

RS-

) = 0V, R

LOAD

= 100kΩ, TA= T

MIN

to

T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Notes 1, 2)

Operating Voltage Range V

Common-Mode Range C

Supply Current I

Leakage Current I

Input Bias Current I

Full-Scale Sense Voltage (Note 4) V

Input Offset Voltage V

Common-Mode Rejection Ratio

Power-Supply Rejection Ratio

OUT High Voltage

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

CC

MVR

CC

RS+

RS+

Inferred from PSRR test 4.5 76 V

Inferred from CMRR test (Note 3) 4.5 76 V

MAX4080 75 190

MAX4081 103 190

= 76V 0.01 2 µA

, I

RS-VCC

, I

RS-VCC

VCC = V
no load

= 0V, V

= V

= 76V,

RS+

RS+

= 76V 5 12 µA

RS+

MAX4080F/MAX4081F ±1000

SENSE

MAX4080T/MAX4081T ±250

MAX4080S/MAX4081S ±100

MAX4080F/MAX4081F 5

MAX4080T/MAX4081T 20Gain A

V

MAX4080S/MAX4081S 60

TA = +25°C ±0.1 ±0.6

VCC = V

V

(Note 5)

RS+

= 48V

TA = -40°C to +85°C ±1Gain Accuracy ΔA

= T

MIN

to T

MAX

T

A

TA = +25°C ±0.1 ±0.6

OS

CMRR V

PSRR V

VCC = V
(Note 6)

CC

RS+

= 48V

RS+

= 48V, V

RS+

TA = -40°C to +85°C ±1

T

= T

MIN

to T

MAX

A

= 4.5V to 76V 100 124 dB

= 48V, VCC = 4.5V to 76V 100 122 dB

MAX4080F/MAX4081F,

= 1000mV

V

V

= 4.5V, V

CC

-

)

= 48V, V
V

REF1B

(sourcing) =

I

OUT

(V

CC

V

OH

REF1A

= 2.5V,

RS+

=

+500µA (Note 8)

SENSE

MAX4080T/MAX4081T,

= 250mV

V

SENSE

MAX4080S/MAX4081S,
V

= 100mV

SENSE

0.15 0.27 V

±1.2

±1.2

µA

mV

V/V

%

mV

MAX4080/MAX4081

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

Voltage Output

_______________________________________________________________________________________ 3

DC ELECTRICAL CHARACTERISTICS (continued)

(VCC= V

RS+

= 4.5V to 76V, V

REF1A

= V

REF1B

= 5V (MAX4081 only), V

SENSE

= (V

RS+

- V

RS-

) = 0V, R

LOAD

= 100kΩ, TA= T

MIN

to

T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Notes 1, 2)

OUT Low Voltage V

REF1A = REF1B Input Voltage
Range (MAX4081 Only)

REF1A Input Voltage Range
(MAX4081 Only)

REF1A Rejection Ratio
(MAX4081 Only)

REF/REF1A Ratio
(MAX4081 Only)

REF1A Input Impedance
(MAX4081 Only)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

(V

OL

(V

REF

GND)

REF1A

GND)

VCC = V
V

REF1A

2.5V, V

-1000mV (for
MAX4081 only)

-

Inferred from REF1A rejection ratio,
V

REF1A

-

Inferred from REF1A rejection ratio,
V

REF1B

VCC = V
V

REF1A

V

REF1A

V

CC

V

REF1B

= 48V,

RS+

= V

REF1B

=

SENSE

= V

REF1B

= GND

= 48V, V

RS+

= V

REF1B

= 10V, V

= V

= 48V (Note 2)

RS+

= GND 250 kΩ

I

=

I
100µA

SENSE

= 1.5V to 6V

REF1B

OUT

OUT

= GND,

(sinking) = 10µA 4 15

(sinking) =

= 0V,

1.5 6 V

312V

80 108 dB

0.497 0.500 0.503

23 55

mV

MAX4080/MAX4081

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

4 _______________________________________________________________________________________

AC ELECTRICAL CHARACTERISTICS

(VCC= V

RS+

= 4.5V to 76V, V

REF1A

= V

REF1B

= 5V (MAX4081 only), V

SENSE

= (V

RS+

- V

RS-

) = 0V, R

LOAD

= 100kΩ, C

LOAD

= 20pF,

T

A

= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Notes 1, 2)

Note 1: All devices are 100% production tested at TA= +25°C. All temperature limits are guaranteed by design.
Note 2: V

REF

is defined as the average voltage of V

REF1A

and V

REF1B

. REF1B is usually connected to REF1A or GND.

V

SENSE

is defined as V

RS+

- V

RS-

.

Note 3: The common-mode range at the low end of 4.5V applies to the most positive potential at RS+ or RS-. Depending on the

polarity of V

SENSE

and the device’s gain, either RS+ or RS- can extend below 4.5V by the device’s typical full-scale value of

V

SENSE

.

Note 4: Negative V

SENSE

applies to MAX4081 only.

Note 5: V

SENSE

is:
MAX4080F, 10mV to 1000mV
MAX4080T, 10mV to 250mV
MAX4080S, 10mV to 100mV
MAX4081F, -500mV to +500mV
MAX4081T, -125mV to +125mV
MAX4081S, -50mV to +50mV

Note 6: V

OS

is extrapolated from the gain accuracy test for the MAX4080 and measured as (V

OUT

- V

REF

)/AVat V

SENSE

= 0V, for the

MAX4081.

Note 7: V

SENSE

is:

MAX4080F, 500mV
MAX4080T, 125mV
MAX4080S, 50mV
MAX4081F/T/S, 0V
V

REF1B

= V

REF1A

= 2.5V

Note 8: Output voltage is internally clamped not to exceed 18V.
Note 9: Output settles to within 1% of final value.
Note 10: The device will not experience phase reversal when overdriven.

Bandwidth BW

OUT Settling Time to 1% of Final
Value

Capacitive-Load Stability No sustained oscillations 500 pF

Output Resistance R

Power-Up Time V

Saturation Recovery Time (Notes 9,10) 50 µs

PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS

MAX4080F/T/S 250

MAX4081F/T/S 150

= 100mV ( Note 9) 50 µs

S E NS E

OUT

V

= V

CC

48V, V

V

SENSE

V

SENSE

V

SENSE

= V

C C

=

RS+

= 2.5V

OUT

= 10mV to 100mV 20

= 100mV to 10mV 20

= 100mV 0.1 Ω

= 48V , V

RS +

kHz

µs

MAX4080/MAX4081

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

Voltage Output

_______________________________________________________________________________________ 5

Typical Operating Characteristics

(VCC= V

RS+

= 48V, V

SENSE

= 0V, C

LOAD

= 20pF, R

LOAD

= ∞, TA= +25°C, unless otherwise noted.)

INPUT OFFSET VOLTAGE HISTOGRAM

35

30

25

20

15

PERCENTAGE (%)

10

5

0

-125 -75 -50 -25-100 0 25 50 75 100 125
INPUT OFFSET VOLTAGE (μV)

MAX4080 toc01

INPUT OFFSET VOLTAGE (μV)

300
250
200
150
100

50

0

-50

-100

-150

-200

-250

-300

-50 25 500-25

COMMON-MODE REJECTION RATIO

0

GAIN ACCURACY vs. V

V

= 48V

RS+

S VERSION

-0.05

-0.10

GAIN ACCURACY (%)

-0.15

-0.20
476

T VERSION

F VERSION

VCC (V)

CC

MAX4080 toc04

6452402816

0

-10

-20

-30

-40

-50

-60

-70

-80

-90

-100

-110

COMMON-MODE REJECTION RATIO (dB)

-120

-130
11M

MAX4081F/T/S

REFERENCE REJECTION RATIO

0

vs. FREQUENCY

-10

-20

-30

-40

-50

-60

-70

-80

-90

REFERENCE REJECTION RATIO (dB)

-100

-110

-120

FREQUENCY (Hz)

MAX4080 toc07

10k1k100101100k

SMALL-SIGNAL GAIN vs. FREQUENCY

50

V

SENSE

45

40

35

30

25

GAIN (dB)

20

15

10

5

0

0.1 1000

INPUT OFFSET VOLTAGE

vs. TEMPERATURE

TEMPERATURE (°C)

MAX4081F/T/S

vs. FREQUENCY

FREQUENCY (Hz)

MAX4080F/T/S

= 10mV

MAX4080S

MAX4080T

MAX4080F

FREQUENCY (kHz)

100 125 150

75

100101

100k10k1k10010

0.5

0.4

MAX4080 toc02

0.3

0.2

0.1

0

-0.1

GAIN ACCURACY (%)

-0.2

-0.3

-0.4

-0.5

-50 -25 0 25 50 75 100 125

0

-10

-20

MAX4080 toc05

-30

-40

-50

-60

-70

-80

-90

-100

-110

POWER-SUPPLY REJECTION RATIO (dB)

-120

-130
11M

50

45

MAX4080 toc08

40

35

30

25

GAIN (dB)

20

15

10

5

0

0.1 1000

GAIN ACCURACY vs. TEMPERATURE

TEMPERATURE (°C)

MAX4081F/T/S

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY

100k10k1k10010

FREQUENCY (Hz)

MAX4081F/T/S

SMALL-SIGNAL GAIN vs. FREQUENCY

V

= 100mV

OUT

P-P

MAX4081S

MAX4081T

MAX4081F

100101

FREQUENCY (kHz)

MAX4080 toc03

MAX4080 toc06

MAX4080 toc09