MAX44285HAWA+ [MAXIM]
Dual-Channel, High-Precision, High-Voltage, Current-Sense Amplifier;
| 型号： | MAX44285HAWA+ |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Dual-Channel, High-Precision, High-Voltage, Current-Sense Amplifier |
| 文件： | 总12页 (文件大小：839K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
EVALUATION KIT AVAILABLE
MAX44285
Dual-Channel, High-Precision,
High-Voltage, Current-Sense Amplifier
General Description
The MAX44285 dual-channel high-side current-sense
amplifier has precision accuracy specifications of V
less than 12μV (max) and gain error less than 0.1%
(max).
Benefits and Features
● 2.7V to 76V Input Common Mode
● Low 12μV (max) Input Offset Voltage
● Low 0.1% (max) Gain Error
OS
● Gain Options
The MAX44285 features an input common-mode voltage
range from 2.7V to 76V with 80kHz of small-signal band-
width, which makes it ideal for interfacing with a SAR ADC
for multichannel multiplexed data acquisition systems.
• G = 12.5V/V (MAX44285L)
• G = 20V/V (MAX44285T)
• G = 50V/V (MAX44285F)
• G = 100V/V (MAX44285H)
The MAX44285 operates over the -40°C to +125°C
temperature range. The MAX44285 is offered in 8-bump
● 1mm x 2mm 8-Bump WLP and 8-Pin µMAX
Packages
M
wafer-level package (WLP) and 8-pin µMAX package.
Applications
● Base Stations and Communication Equipment
● Power Management Systems
● Server Backplanes
µMAX is a registered trademark of Maxim Integrated Products, Inc.
● Industrial Control and Automation
Typical Operating Circuit
ISENSE1
RSENSE1
VCM = 2.7V TO 76V
SYSTEM
LOAD 1
RSENSE2
ISENSE2
VCM = 2.7V TO 76V
SYSTEM
LOAD 2
RS1+
VDD
RS1- RS2+
RS2-
VDD = 2.7V TO
5.5V
OUT2
OUT1
MAX44285
GND
Ordering Information appears at end of data sheet.
19-6910; Rev 4; 4/16
MAX44285
Dual-Channel, High-Precision,
High-Voltage, Current-Sense Amplifier
Absolute Maximum Ratings
V
to GND .........................................................-0.3V to +6.0V
Continuous Power Dissipation (T = +70°C)
DD
A
RS+, RS- to GND..................................................-0.3V to +80V
RS+ to RS-
WLP (derate 13.3mW/°C above +70°C)....................1064mW
µMAX (derate 4.8mW/°C above +70°C)...................387.8mW
Operating Temperature Range......................... -40°C to +125°C
Junction Temperature......................................................+150°C
Storage Temperature Range............................ -65°C to +150°C
Lead Temperature (soldering, 10s)(µMAX only) .............+300°C
Soldering Temperature (reflow).......................................+260°C
µMAX (1s maximum duration due to package thermal
dissipation.......................................................................±80V
WLP (1s maximum duration due to package thermal
dissipation.......................................................................±50V
Continuous Input Current (Any Pin).................................±20mA
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.
(Note 1)
Package Thermal Characteristics
WLP
µMAX
Junction-to-Ambient Thermal Resistance (θ ) .....206.3°C/W
Junction-to-Ambient Thermal Resistance (θ ) ..........75°C/W
JA
JA
Junction-to-Case Thermal Resistance (θ )...............42°C/W
JC
Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.
Electrical Characteristics
(V
= V
= +76V, V
= +3.3V, V
= V
- V
= 1mV, T = -40°C to +125°C, unless otherwise noted. Typical values are
RS- A
RS+
RS-
DD
SENSE
RS+
at T =+25°C.) (Note 2)
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DC CHARACTERISTICS
Supply Voltage
V
Guaranteed by PSRR
= +25°C
2.7
5.5
V
DD
T
1300
1500
A
Supply Current
I
µA
DD
-40°C < T < +125°C
A
Power-Supply Rejection
Ratio
PSRR
2.7V ≤ V
≤ 5.5V
110
2.7
120
dB
V
DD
Input Common-Mode
Voltage Range
V
Guaranteed by CMRR
76
65
CM
Input Bias Current at V
RS+
I
, I
µA
RS+ RS-
and V
(Note 3)
RS-
Input Offset Current
(Note 3)
I
-I
1100
6
nA
µA
RS+ RS-
Input Leakage Current
(Note 3)
I
, I
V
= 0V, V
= 76V
RS+ RS-
DD
RS+
Common-Mode Rejection
Ratio
CMRR
4.5V < V
< 76V
125
140
dB
RS+
T
= +25°C
±12
±25
Input Offset Voltage
(Note 3)
A
V
µV
OS
-40°C ≤ T ≤ +125°C
A
Input Offset Voltage Drift
(Note 3)
TCV
130
nV/°C
OS
Maxim Integrated
│ 2
www.maximintegrated.com
MAX44285
Dual-Channel, High-Precision,
High-Voltage, Current-Sense Amplifier
Electrical Characteristics (continued)
(V
= V
= +76V, V
= +3.3V, V
= V
- V
= 1mV, T = -40°C to +125°C, unless otherwise noted. Typical values are
RS+
RS-
DD
SENSE
RS+
RS- A
at T =+25°C.) (Note 2)
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
200
125
50
MAX
UNITS
MAX44285L (G = 12.5V/V)
MAX44285T (G = 20V/V)
MAX44285F (G = 50V/V)
MAX44285H (G = 100V/V)
Input Sense Voltage
V
mV
SENSE
25
Full-scale V
Full-scale V
Full-scale V
Full-scale V
= 200mV
= 125mV
= 50mV
= 25mV
12.5
20
SENSE
SENSE
SENSE
SENSE
Gain (Note 4)
G
V/V
%
50
100
T
= +25°C
0.1
0.3
0.5
A
Gain Error (Note 3)
GE
-40°C ≤ T ≤ +85°C
A
-40°C ≤ T ≤ +125°C
A
Output Resistance
Output Low Voltage
R
0.1
mΩ
OUT
Sink 500µA
15
4
V
mV
OL
No load
V
0.015
-
DD
Output High Voltage
V
Source 500µA
V
OH
AC CHARACTERISTICS
Signal Bandwidth
BW -3dB
All gain configurations V
f = 200kHz
> 5mV
80
40
kHz
dB
SENSE
AC Power-Supply
Rejection Ratio
AC PSRR
1mV sine wave
20mV sine wave
54
AC CMRR
AC CMRR f = 200kHz
dB
µs
47
Output Transient Recovery
Time
∆V
= 2V , 14-bit settling with 400Ω
and 1nF, 6nF ADC sampling capacitor
OUT P-P
2
With 250Ω isolation resistor
20
nF
pF
Capacitive Load Stability
C
LOAD
Without any isolation resistor
200
Input Voltage-Noise
Density
e
n
f = 1kHz
45
nV/√Hz
Total Harmonic Distortion
(Up to 7th Harmonics)
63
dB
THD
f = 1kHz, V
= 1V
OUT P-P
Power-Up Time (Note 5)
Saturation Recovery Time
200
10
µs
µs
Note 2: All devices are 100% production tested at T = +25°C. All temperature limits are guaranteed by design.
A
Note 3: Specifications are guaranteed by design, not production tested.
Note 4: Gain and offset voltage are calculated based on two point measurements: V
and V
.
SENSE1
SENSE2
V
= 20% x Full Scale V
. V
= 80% x Full Scale V
.
SENSE1
SENSE SENSE2
SENSE
Note 5: Output is high-Z during power-up.
Maxim Integrated
│ 3
www.maximintegrated.com
MAX44285
Dual-Channel, High-Precision,
High-Voltage, Current-Sense Amplifier
Typical Operating Characteristics
(V
= V
= 76V, V
= 3.3V, V
= V
- V
= 1mV, T = +25°C, unless otherwise noted.) (Note 2)
RS+
RS-
DD
SENSE
RS+
RS-
A
INPUT-REFERRED OFFSET
INPUT OFFSET VOLTAGE HISTOGRAM
vs. TEMPERATURE
toc02
toc01
10
16
14
12
10
8
VDD = 3.3V
8
6
G =12.5V/V
4
2
G = 20V/V
0
G = 50V/V
-2
-4
-6
-8
-10
6
4
G = 100V/V
2
0
-50
0
50
100
150
-4
-3
-2
-1
0
1
2
3
4
INPUT OFFSET VOLTAGE (µV)
TEMPERATURE (C˚)
INPUT-REFERRED OFFSET
vs. COMMON-MODE VOLTAGE
GAIN ERROR
vs. TEMPERATURE
toc03
toc04
12
10
8
0.06
0.04
0.02
0
VDD = 3.3V
G = 12.5V/V
G = 12.5V/V
6
G = 20V/V
4
-0.02
-0.04
-0.06
-0.08
-0.1
G = 20V/V
2
G = 50V/V
G = 100V/V
0
-2
-4
-6
G = 100V/V
G = 50V/V
60
-0.12
0
20
40
80
-50
0
50
100
150
COMMON-MODE VOLTAGE (V)
TEMPERATURE (°C)
GAIN ERROR
vs. COMMON-MODE VOLTAGE
AC CMRR
vs. FREQUENCY
toc06
toc05
0.1
0.08
0.06
0.04
0.02
0
120
110
100
90
80
70
60
50
40
30
20
10
0
VDD = 3.3V
G =100V/V
G = 50V/V
G = 12.5V/V
-0.02
-0.04
-0.06
G = 20V/V
20
0
40
60
80
10
100
1000
10000 100000 1000000
COMMON-MODE VOLTAGE (V)
FREQUENCY (Hz)
Maxim Integrated
│ 4
www.maximintegrated.com
MAX44285
Dual-Channel, High-Precision,
High-Voltage, Current-Sense Amplifier
Typical Operating Characteristics (continued)
(V
= V
= 76V, V
= 3.3V, V
= V
- V
= 1mV, T = +25°C, unless otherwise noted.) (Note 2)
RS+
RS-
DD
SENSE
RS+
RS-
A
GAIN
vs. FREQUENCY
AC PSRR
vs. FREQUENCY
toc08
toc07
140
120
100
80
45
40
G = 100V/V
35
30
G = 50V/V
G = 20V/V
25
20
15
10
5
G = 12.5V/V
60
40
20
0
1
100
10000
1000000
1
100
10000
FREQUENCY (Hz)
FREQUENCY (Hz)
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
SUPPLY CURRENT
vs. TEMPERATURE
toc9
toc10
950
940
920
900
880
860
840
820
VDD = 3.3V
900
850
800
750
700
650
600
G = 100V/V
G = 20V/V
G = 12.5V/V
G = 50V/V
G = 50V/V
G = 12.5V/V
-20
G = 20V/V
G = 100V/V
2.7
3.1
3.5
3.9
4.3
4.7
5.1
5.5
-45
5
30
55
80
105 130
SUPPLY VOLTAGE (V)
TEMPERATURE (˚C)
OUTPUT VOLTAGE HIGH
vs. SOURCE CURRENT
OUTPUT VOLTAGE LOW
vs. SINK CURRENT
toc11
toc12
250
200
150
100
50
160
140
120
100
80
G = 20V/V
G = 20V/V
60
40
20
0
0
0
2
4
6
8
10
0
2
4
6
8
10
SOURCE CURRENT (mA)
SINK CURRENT (mA)
Maxim Integrated
│ 5
www.maximintegrated.com
MAX44285
Dual-Channel, High-Precision,
High-Voltage, Current-Sense Amplifier
Typical Operating Characteristics (continued)
(V
= V
= 76V, V
= 3.3V, V
= V
- V
= 1mV, T = +25°C, unless otherwise noted.) (Note 2)
RS+
RS-
DD
SENSE
RS+
RS-
A
LARGE-SIGNAL STEP RESPONSE
SMALL-SIGNAL STEP RESPONSE
toc14
toc13
4
10kΩ LOAD
VIN
120mV
VIN
20mV
50mV/div
10mV/div
VOUT
200mV/div
VOUT
1V/div
400μs/div
400μs/div
SATURATION RECOVERY RESPONSE
INPUT VOLTAGE-NOISE DENSITY
vs. FREQUENCY
toc15
toc16
600
500
400
300
200
100
0
NO LOAD
VIN
200mV
100mV/div
VOUT
1V/div
400μs/div
10
1000
100000
FREQUENCY (Hz)
TOTAL HARMONIC DISTORTION
vs. FREQUENCY
toc17
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
1VP-P OUTPUT
G = 20V/V
10
100
1000
10000
100000
FREQUENCY (Hz)
Maxim Integrated
│ 6
www.maximintegrated.com
MAX44285
Dual-Channel, High-Precision,
High-Voltage, Current-Sense Amplifier
Pin Configuration
TOP VIEW
BOTTOM VIEW
+
RS1+
RS1-
RS2+
RS2-
1
2
3
4
8
7
6
5
V
DD
B
A
V
OUT1 OUT2
GND
RS2-
4
DD
OUT1
OUT2
GND
MAX44285
µMAX
RS1+
1
RS1-
2
RS2+
3
WLP
Pin Description
PIN
NAME
FUNCTION
WLP
A1
A2
A3
A4
B1
B2
B3
B4
µMAX
1
2
3
4
8
7
6
5
RS1+
RS1-
RS2+
RS2-
Channel 1 External Resistor Power-Side Connection
Channel 1 External Resistor Load-Side Connection
Channel 2 External Resistor Power-Side Connection
Channel 2 External Resistor Load-Side Connection
Supply Voltage
V
DD
OUT1
OUT2
GND
Output Channel 1
Output Channel 2
Ground
Maxim Integrated
│ 7
www.maximintegrated.com
MAX44285
Dual-Channel, High-Precision,
High-Voltage, Current-Sense Amplifier
Functional Diagram
VSENSE1
VSENSE2
ILOAD1
ILOAD2
RSENSE 1
RSENSE 2
RS2-
RS1+
RG11
RS1-
RS2+
RG21
RG12
RG22
MAX44285
A1
A1
P1
P
P
P2
A2
A2
R01
R02
RF1
RF2
R01
R02
GND
GND
OUT1
OUT2
equals the voltage drop (V
) across the external
SENSE
Detailed Description
sense resistor (R
). The internal resistor at RS1- pin
SENSE
The MAX44285 high-side, current-sense amplifier fea-
tures a 2.7V to 76V input common-mode range that is
independent of supply voltage. This feature allows the
monitoring of current out of a battery as low as 2.7V and
enables high-side current sensing at voltages greater
(R
) has the same value as R
G12
to minimize error.
G11
The current through R
is sourced by a high-voltage
G11
p-channel FET. Its source current is the same as the drain
current which flows through a second gain resistor, R
01,
producing a voltage V
= V
x R /R
.
R01
SENSE
01 G11
than the supply voltage (V ). The MAX44285 monitors
DD
The output voltage V
is produced from a second op
current through a current-sense resistor and amplifies the
OUT1
amp A2 with the gain (1 + R /R ). Hence, the V
=
voltage across the resistor.
F1 01
OUT1
I
x R
(R /R
) x (1 + R / R ) for chan-
LOAD1
SENSE1 01 G11 F1 01
OUT2
High-side current monitoring does not interfere with the
ground path of the load being measured, making the
MAX44285 particularly useful in a wide range of high-
voltage systems.
nel 1 and V
R
= R
resistors R , R , R
R
= I
x R
(R /R
) x (1 +
LOAD2
SENSE2
02 G21
/ R ) for channel 2. Internal resistor R = R , R
F2 02
01 02 G11
= R . The gain-setting
F1 F2
= R
= R
, R
G22
G12
G21
, R
, R
G12
, R
G21
, R
G22
and
01
02
G11
F1,
The MAX44285 operates as follows: current from the
are available in Table 1):
F2
source flows through R
to the load (see Functional
SENSE
Total gain = 12.5V/V for MAX44285L, 20V/V for the
MAX44285T, 50V/V for the MAX44285F, and 100V/V for
the MAX44285H.
Diagram), creating a sense voltage, V
. The internal
SENSE
op amp A1 is used to force the current through an internal
gain resistor R at RS1+ pin, such that its voltage drop
G11
Maxim Integrated
│ 8
www.maximintegrated.com
MAX44285
Dual-Channel, High-Precision,
High-Voltage, Current-Sense Amplifier
Table 1. Gain-Setting Resistors
GAIN (V/V)
R
, R (kW)
R
, R
, R
, R
(kW)
R , R (kW)
F1 F2
01 02
G11 G12 G21 G22
MAX44285L
MAX44285T
MAX44285F
MAX44285H
12.5
20
25
25
25
25
10
10
10
10
100
175
475
975
50
100
Efficiency and Power Dissipation: At high current
Applications Information
2
levels, the I R losses in R
can be significant.
SENSE
Recommended Component Values
Consider this when choosing the resistor value and its
power dissipation (wattage) rating. In addition, the sense
resistor’s value might drift if it heats up excessively.
Ideally, the maximum load current develops the full-scale
sense voltage across the current-sense resistor. Choose
the gain needed to yield the maximum output voltage
required for the application:
Inductance: Keep inductance low if I
has a large
SENSE
high-frequency component. Wire-wound resistors have
the highest inductance, while metal film is somewhat
better. Low-inductance, metal-film resistors are also
available. Instead of being spiral wrapped around a core,
as in metal-film or wire wound resistors, they are a straight
band of metal and are available in values under 1Ω.
V
OUT
= V
x A
SENSE V
where V
is the full-scale sense voltage, 200mV for
SENSE
gain of 12.5V/V, 125mV for gain of 20V/V, 50mV for gain
of 50V/V, 25mV for gain of 100V/V, and A is the gain of
the device.
V
Take care to eliminate parasitic trace resistance from
causing errors in the sense voltage because of the high
In applications monitoring a high current, ensure that
2
R
is able to dissipate its own I R loss. If the resis-
SENSE
currents that flow through R
. Either use a four
tor’s power dissipation exceeds the nominal value, its
value may drift or it may fail altogether. The MAX44285
senses a wide variety of currents with different sense-
resistor values.
SENSE
terminal current-sense resistor or use Kelvin (force and
sense) PCB layout techniques.
Base Station Application Circuit
Choosing the Sense Resistor
An example of a typical application (Figure 1) of this
high-voltage, high-precision current-sense amplifier is in
base-station systems where there is a need to monitor
the current flowing in the power amplifier. Such amplifiers,
depending on the technology, can be biased up to 50V
or 60V thus requiring a current-sense amplifier like the
MAX44285 with high-voltage common mode. The very
low input offset voltage of the MAX44285 minimizes
the value of the external sense resistor thus resulting in
system power-saving.
Choose R
based on the following criteria:
SENSE
Voltage Loss: A high R
value causes the power-
SENSE
source voltage to degrade through IR loss. For minimal
voltage loss, use the lowest R
value.
SENSE
Accuracy: A high R
value allows lower currents
SENSE
measured more accurately. This is due to offsets becoming
less significant when the sense voltage is larger. For best
performance, select R
to provide approximately
SENSE
200mV (gain of 12.5V/V), 125mV (gain of 20V/V), or
50mV (gain of 50V/V), 25mV (gain of 100V/V) of sense
voltage for the full-scale current in each application.
Maxim Integrated
│ 9
www.maximintegrated.com
MAX44285
Dual-Channel, High-Precision,
High-Voltage, Current-Sense Amplifier
V
= 3.3V
DD
MAX6126
OUTF OUTS
V
= 3.3V
DD
REF+
REF-
250Ω
20Ω
OUTPUT
V
MAX44285
IN
MAX11125
20nF
220nF
V
= 2.7V TO 76V
DRAIN
µC
RFOUT
RFIN
Figure 1. MAX44285 Used in Base-Station Application
Maxim Integrated
│ 10
www.maximintegrated.com
MAX44285
Dual-Channel, High-Precision,
High-Voltage, Current-Sense Amplifier
Ordering Information
PART
MAX44285LAWA+
MAX44285LAUA+
MAX44285TAWA+
MAX44285TAUA+
MAX44285FAWA+
MAX44285FAUA+
MAX44285HAWA+
MAX44285HAUA+
GAIN (V/V)
12.5
12.5
20
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
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
PIN-PACKAGE
8 WLP
TOP MARK
+AAF
—
8 µMAX
8 WLP
+AAG
—
20
8 µMAX
8 WLP
50
+AAH
—
50
8 µMAX
8 WLP
100
+AAI
—
100
8 µMAX
+Denotes a lead(Pb)-free/RoHS-compliant package.
Package Information
Chip Information
PROCESS: BiCMOS
For the latest package outline information and land patterns
(footprints), go to www.maximintegrated.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.
PACKAGE PACKAGE OUTLINE
LAND
TYPE
CODE
NO.
PATTERN NO.
Refer to
Application Note 1891
8 WLP
W81A2+2
U8+1
21-0210
21-0036
8 µMAX
90-0092
Maxim Integrated
│ 11
www.maximintegrated.com
MAX44285
Dual-Channel, High-Precision,
High-Voltage, Current-Sense Amplifier
Revision History
REVISION REVISION
PAGES
CHANGED
DESCRIPTION
NUMBER
DATE
0
1
2
3
4
1/14
Initial release
—
2/14
Revised Pin Description, Functional Diagram, Detailed Description and added Table 1
Revised data sheet to change common-mode range from 36V to 76V
Released WLP packages and updated Electrical Characteristics
Updated unit in TOC1
7, 8, 9
1–6. 8–10
2, 11
7/14
12/14
4/16
4
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated 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.
©
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
2016 Maxim Integrated Products, Inc.
│ 12
相关型号：
MAX44285TAUA+
Operational Amplifier, 2 Func, 25uV Offset-Max, BICMOS, PDSO8, ROHS COMPLIANT, USOP, UMAX-8
MAXIM
©2020 ICPDF网 联系我们和版权申明