EVALUATION KIT AVAILABLE
MAX4080/MAX4081
76V, High-Side, Current-Sense Amplifiers
with Voltage Output
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 uni-
directional current-sense applications and the MAX4081
allows bidirectional current sensing. The MAX4081 sin-
gle output pin continuously monitors the transition from
charge to discharge and avoids the need for a separate
polarity output. The MAX4081 requires an external refer-
ence to set the zero-current output level (V
SENSE
= 0V).
The charging current is represented by an output voltage
from V
REF
to V
CC
, 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 sys-
tems.
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, accu-
rate, 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 tem-
perature range (-40°C to +125°C) and are available in a
space-saving 8-pin µMAX® or SO package.
●
●
●
●
●
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
µMAX is a registered trademark of Maxim Integrated Products, Inc.
Benefits and Features
●
Ideal for High-Voltage Current Monitoring Applications
• Wide 4.5V to 76V Input Common-Mode Range
• Independent Operating Supply Voltage
●
High Accuracy and Low Quiescent Current Support
Precision Application Requirements
• ±0.1% Full-Scale Accuracy
•
Low 100μV Input Offset Voltage
• Three Gain Versions Available
- 5V/V (MAX4080F/MAX4081F)
- 20V/V (MAX4080T/MAX4081T)
- 60V/V (MAX4080S/MAX4081S)
•
75μA Supply Current (MAX4080)
●
Flexible Current Sensing Supports Monitoring of
Charge and Discharge of Batteries
• Bidirectional (MAX4081) or Unidirectional
(MAX4080) I
SENSE
• Reference Input for Bidirectional OUT (MAX4081)
●
Minimizes Required Board Space
•
8-Pin μMAX Package
Ordering Information
PART
MAX4080FAUA+
MAX4080FAUA/V+
MAX4080FASA+
MAX4080TAUA+
MAX4080TAUA/V+
TEMP RANGE
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
PIN-PACKAGE
8 µMAX
8 µMAX
8 SO
8 µMAX
8 µMAX
+Denotes a lead(Pb)-free/RoHS-compliant package.
/V denotes an automotive qualified part.
Ordering Information continued at end of data sheet.
Selector Guide appears at end of data sheet.
Applications
Pin Configurations
TOP VIEW
RS+ 1
V
CC
2
N.C.
3
+
MAX4080
8
7
6
5
RS-
N.C.
N.C.
OUT
RS+ 1
V
CC
2
N.C.
3
+
MAX4081
8
7
6
5
RS-
REF1A
REF1B
OUT
GND 4
GND 4
µMAX/SO
µMAX/SO
19-2562; Rev 5; 5/15
MAX4080/MAX4081
76V, High-Side, Current-Sense Amplifiers
with Voltage Output
Absolute Maximum Ratings
V
CC
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 (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+
- V
RS-
) ..............................±80V
Current into Any Pin .........................................................±20mA
Continuous Power Dissipation (T
A
= +70°C)
8-Pin ?MAX (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
Soldering Temperature (reflow) .......................................+260°C
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.
DC Electrical Characteristics
PARAMETER
Operating Voltage Range
Common-Mode Range
Supply Current
Leakage Current
Input Bias Current
Full-Scale Sense Voltage
(Note 4)
(V
CC
= V
RS+
= 4.5V to 76V, V
REF1A
= V
REF1B
= 5V (MAX4081 only), V
SENSE
= (V
RS+
- V
RS-
) = 0V, R
LOAD
= 100kΩ, T
A
= T
MIN
to
T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.) (Notes 1, 2)
SYMBOL
V
CC
C
MVR
I
CC
I
RS+
, I
RS-
I
RS+
, I
RS-
V
SENSE
CONDITIONS
Inferred from PSRR test
Inferred from CMRR test (Note 3)
V
CC
= V
RS+
= 76V, MAX4080
no load
MAX4081
V
CC
= 0V, V
RS+
= 76V
V
CC
= V
RS+
= 76V
MAX4080F/MAX4081F
MAX4080T/MAX4081T
MAX4080S/MAX4081S
MAX4080F/MAX4081F
Gain
A
V
MAX4080T/MAX4081T
MAX4080S/MAX4081S
Gain Accuracy
DA
V
V
CC
= V
RS+
= 48V
(Note 5)
V
CC
= V
RS+
= 48V
(Note 6)
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= T
MIN
to T
MAX
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= T
MIN
to T
MAX
100
100
124
122
±0.1
MIN
4.5
4.5
75
103
0.01
5
±1000
±250
±100
5
20
60
±0.1
±0.6
±1
±1.2
±0.6
±1
±1.2
dB
dB
mV
%
V/V
mV
TYP
MAX
76
76
190
190
2
12
UNITS
V
V
µA
µA
µA
Input Offset Voltage
Common-Mode Rejection Ratio
(Note 7)
Power-Supply Rejection Ratio
(Note 7)
V
OS
CMRR
PSRR
V
CC
= 48V, V
RS+
= 4.5V to 76V
V
RS+
= 48V, V
CC
= 4.5V to 76V
V
CC
= 4.5V, V
RS+
= 48V, V
REF1A
=
V
REF1B
= 2.5V,
I
OUT
(sourcing) =
+500µA (Note 8)
MAX4080F/MAX4081F,
V
SENSE
= 1000mV
MAX4080T/MAX4081T,
V
SENSE
= 250mV
MAX4080S/MAX4081S,
V
SENSE
= 100mV
OUT High Voltage
(V
CC
–
V
OH
)
0.15
0.27
V
www.maximintegrated.com
Maxim Integrated
│
2
MAX4080/MAX4081
76V, High-Side, Current-Sense Amplifiers
with Voltage Output
DC Electrical Characteristics (continued)
PARAMETER
SYMBOL
(V
CC
= V
RS+
= 4.5V to 76V, V
REF1A
= V
REF1B
= 5V (MAX4081 only), V
SENSE
= (V
RS+
- V
RS-
) = 0V, R
LOAD
= 100kΩ, T
A
= T
MIN
to
T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.) (Notes 1, 2)
CONDITIONS
V
CC
= V
RS+
= 48V,
I
(sinking) = 10µA
V
REF1A
= V
REF1B
=
OUT
2.5V, V
SENSE
=
-1000mV (for
I
OUT
(sinking) = 100µA
MAX4081 only)
Inferred from REF1A rejection ratio,
V
REF1A
= V
REF1B
1.5
3
80
0.497
108
0.500
250
0.503
kΩ
MIN
TYP
4
MAX
15
UNITS
OUT Low Voltage
V
OL
23
55
6
12
V
V
dB
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)
(V
REF
–
V
GND
)
(V
REF1A
– Inferred from REF1A rejection ratio,
V
GND
)
V
REF1B
= V
GND
V
CC
= V
RS+
= 48V, V
SENSE
= 0V,
V
REF1A
= V
REF1B
= 1.5V to 6V
V
REF1A
= 10V, V
REF1B
= V
GND
,
V
CC
= V
RS+
= 48V (Note 2)
V
REF1B
= V
GND
www.maximintegrated.com
Maxim Integrated
│
3
MAX4080/MAX4081
76V, High-Side, Current-Sense Amplifiers
with Voltage Output
AC Electrical Characteristics
PARAMETER
Bandwidth
OUT Settling Time to 1% of Final
Value
Capacitive-Load Stability
Output Resistance
Power-Up Time
Saturation Recovery Time
R
OUT
(V
CC
= VRS+ = 4.5V to 76V, VREF1A = VREF1B = 5V (MAX4081 only), VSENSE = (VRS+ - VRS-) = 0V, RLOAD = 100kΩ, C
LOAD
= 20pF,
T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.) (Notes 1, 2)
SYMBOL
BW
CONDITION
V
CC
= V
RS+
= 48V, MAX4080F/T/S
V
OUT
= 2.5V
MAX4081F/T/S
V
SENSE
= 10mV to 100mV
V
SENSE
= 100mV to 10mV
No sustained oscillations
V
SENSE
= 100mV
V
CC
= V
RS+
= 48V, V
SENSE
= 100mV (Note 9)
(Notes 9,10)
MIN
TYP
250
150
20
20
500
0.1
50
50
MAX
UNITS
kHz
µs
pF
Ω
µs
µs
Note 1:
All devices are 100% production tested at T
A
= +25°C. All temperature limits are guaranteed by design.
Note 2:
V
REF
is defined as the average voltage of V
REF1A
and VREF1B. 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
)/AV at 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.
www.maximintegrated.com
Maxim Integrated
│
4
MAX4080/MAX4081
76V, High-Side, Current-Sense Amplifiers
with Voltage Output
Typical Operating Characteristics
(V
CC
= V
RS+
= 48V, V
SENSE
= 0V, C
LOAD
= 20pF, R
LOAD
= ∞, T
A
= +25°C, unless otherwise noted.)
MAX4080 toc02
MAX4080 toc01
30
PERCENTAGE (%)
25
20
15
10
5
0
-125 -100 -75 -50 -25 0 25 50 75 100 125
INPUT OFFSET VOLTAGE (
µ
V)
INPUT OFFSET VOLTAGE (V)
GAIN ACCURACY (%)
200
150
100
50
0
-50
0.4
0.3
0.2
0.1
0
-0.1
-0.2
-0.3
-0.4
-0.5
-100
-150
-200
-250
-300
-50 -25
0
75 100 125 150
TEMPERATURE (
°
C)
25
50
-50
-25
0
25
50
75
100
125
TEMPERATURE (°C)
MAX4080 toc04
MAX4080 toc05
S VERSION
GAIN ACCURACY (%)
-0.05
-0.10
T VERSION
-0.15
F VERSION
-0.20
4
16
28
40
V
CC
(V)
52
64
76
1
10
100
1k
10k
100k
POWER-SUPPLY REJECTION RATIO (dB)
COMMON-MODE REJECTION RATIO (dB)
V
RS+
= 48V
1M
1
10
100
1k
10k
100k
1M
FREQUENCY (Hz)
FREQUENCY (Hz)
MAX4080 toc07
MAX4080 toc08
REFERENCE REJECTION RATIO (dB)
-10
-20
-30
-40
45
40
35
GAIN (dB)
30
25
20
15
10
5
0
V
SENSE
= 10mV
MAX4080S
MAX4080T
45
40
35
GAIN (dB)
30
25
20
15
10
5
0
V
OUT
= 100mV
P-P
MAX4081S
MAX4081T
-50
-60
-70
-80
-90
-100
-110
-120
1
10
100
1k
10k
100k
MAX4080F
MAX4081F
0.1
1
10
FREQUENCY (kHz)
100
1000
0.1
1
10
FREQUENCY (kHz)
100
1000
FREQUENCY (Hz)
www.maximintegrated.com
Maxim Integrated
│
5
MAX4080 toc09
0
MAX4081F/T/S
REFERENCE REJECTION RATIO
vs. FREQUENCY
50
MAX4080F/T/S
SMALL-SIGNAL GAIN vs. FREQUENCY
50
MAX4081F/T/S
SMALL-SIGNAL GAIN vs. FREQUENCY
MAX4080 toc06
0
GAIN ACCURACY vs. V
CC
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
-120
-130
MAX4081F/T/S
COMMON-MODE REJECTION RATIO
vs. FREQUENCY
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
-120
-130
MAX4081F/T/S
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
MAX4080 toc03
35
INPUT OFFSET VOLTAGE HISTOGRAM
INPUT OFFSET VOLTAGE
vs. TEMPERATURE
300
250
0.5
GAIN ACCURACY vs. TEMPERATURE