MAX4069_V01 [MAXIM]
Bidirectional, High-Side, Current-Sense Amplifiers with Reference;
| 型号： | MAX4069_V01 |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Bidirectional, High-Side, Current-Sense Amplifiers with Reference |
| 文件： | 总14页 (文件大小：2162K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
MAX4069–MAX4072
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
General Description
Features
The MAX4069–MAX4072 low-cost, bidirectional, high-
side, current-sense amplifiers are ideal for monitoring
battery charge and discharge currents in notebooks, cell
phones, and other portable equipment. They feature up
to 24V input common-mode voltage range, low 100µA
supply current (which drops to only 10µA in shutdown),
and a total output error of less than 1.5%. The wide 1.35V
to 24V input common-mode range is independent of the
supply voltage, ensuring that the current-sense feedback
remains accurate even when connected to a battery pack
in deep discharge.
● Bidirectional, Compact, Current-Sense Solution
● Total Output Error Less than 1.5%
● Selectable Gain of 50V/V or 100V/V
● Wide 1.35V to 24V Common-Mode Range
Independent of Supply Voltage
● 2.7V to 24V Single-Supply Operation
● Internal Precision Reference
•ꢀ Adjustable (MAX4069)
•ꢀ 2.50V (MAX4070)
•ꢀ 1.50V (MAX4071)
To achieve maximum flexibility, an external current-sense
resistor is used along with a Gain Select pin to choose
either 50V/V or 100V/V. A single output pin continuously
monitors the transition from charge to discharge and
avoids the need for a separate polarity output. The
MAX4070 contains an internal 2.5V reference. The charging
current is represented by an output voltage from 2.5V to
●
●
Lowꢀ100μAꢀSupplyꢀCurrent
10μAꢀSupplyꢀCurrentꢀinꢀShutdown
● Available in Space-Saving Packages
•ꢀ 8-Pin Thin QFN (MAX4070/MAX4071/MAX4072)
•ꢀ 8-PinꢀμMAXꢀ(MAX4070/MAX4071/MAX4072)
•ꢀ 10-PinꢀμMAXꢀ(MAX4069)
V
CC
, while discharge current is given from 2.5V to GND.
The MAX4071 is similar, but with a reference voltage of
1.5V. The MAX4069 has an adjustable reference voltage,
set by two external resistors. The MAX4072 has an input
for an external reference.
Ordering Information
TOP
MARK
PART
TEMP RANGE PIN-PACKAGE
MAX4069AUB+ -40°C to +125°C 10 µMAX
MAX4070AUA+ -40°C to +125°C 8 µMAX
MAX4070ATA+ -40°C to +125°C 8 Thin QFN-EP*
MAX4071AUA+ -40°C to +125°C 8 µMAX
MAX4071ATA+ -40°C to +125°C 8 Thin QFN-EP*
MAX4072AUA+ -40°C to +125°C 8 µMAX
MAX4072ATA+ -40°C to +125°C 8 Thin QFN-EP*
*EP = Exposed pad.
—
The MAX4069/MAX4071/MAX4072 operate from a 2.7V
to 24V single supply. The MAX4070 operates from a
3.6V to 24V single supply. All devices are specified over
the automotive operating temperature range, -40°C to
+125°C. The MAX4070/MAX4071/MAX4072 are available in
8-pin µMAX and 8-pin thin QFN packages. The MAX4069
—
ADH
—
ADI
—
®
is available in a 10-pin µMAX package.
ADJ
Applications
● Notebook Fuel Gauging
● Smart-Battery Packs/Chargers
● Motor Control
● Power-Management Systems
● Cell-Phone Battery-Current Monitoring
Typical Operating Circuit
FROM BATTERY
CHARGER
R
SENSE
V
BATT
= 1.35V TO 24V
LOAD
RS-
RS+
V
CC
= 3.6V TO 24V
V
CC
MAX4070
μMAX is a registered trademark of Maxim Integrated Products,
Inc.
GSEL
SHDN
OUT
TO ADC
REFOUT
2.5V
Pin Configurations and Selector Guide appear at end of
data sheet.
GND
19-2423; Rev 4; 11/16
MAX4069–MAX4072
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
Absolute Maximum Ratings
V
, RS+, RS- to GND.........................................-0.3V to +26V
Continuous Power Dissipation (T = +70°C)
A
CC
OUT to GND................. -0.3V to Lesser of (V
+ 0.3V) or 15V
8-Pin µMAX (derate 4.5mW/°C above +70°C)............362mW
8-Pin Thin QFN (derate 24.4mW/°C above +70°C)....1951mW
10-Pin µMAX (derate 5.6 mW/°C above +70°C)......444.4mW
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
CC
Differential Input Voltage (V
- V
).............................±0.3V
RS+
RS-
GSEL, SHDN, REFOUT, REFIN
and ADJ to GND................................... -0.3V to (V
OUT Short-Circuit Duration to GND
+ 0.3V)
CC
or to Lesser of (V
or 15V).................................Continuous
CC
REFOUT Short Circuit to V
or GND .....................Continuous
CC
Current into 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.
Electrical Characteristics
(V
= V
= V
= 2.7V to 24V, V
= V
- V
= 0V, I
= 0, V
= V , V
= GND, V
= 2.5V
RS+
RS-
CC
SENSE
RS+
RS-
REFOUT
SHDN
CC
GSEL
= V
REFIN
(MAX4072), T = T
to T
, unless otherwise noted. Typical values are at T = +25°C and at V
= 12V.) (Notes 1, 2)
A
MIN
MAX
A
CC
RS+
PARAMETER
SYMBOL
CONDITIONS
MAX4069/MAX4071/MAX4072 (Note 4)
MAX4070
MIN
TYP
MAX
24
UNITS
2.7
3.6
Operating Voltage Range
(Note 3)
V
V
CC
24
T
T
T
= +25°C
0.08
0.25
0.8
1
A
A
A
Input-Referred Offset Voltage
(Note 5)
V
V
= V =
RS+
= 12V
CC
V
= -40°C to +85°C
mV
OS
RS-
= T
to T
MAX
MIN
Common-Mode Input Range
CMVR
CMRR
Guaranteed by CMRR test
1.35Vꢀ≤ꢀV = V ꢀ≤ꢀ24V,ꢀV
1.35
100
24
V
Common-Mode Rejection Ratio
= 12V
120
100
dB
RS+ RS- CC
V
= V
RS+
= V
= 24V, R = open,
L
CC
= T
RS-
Supply Current
I
250
µA
µA
CC
T
to T
A
MIN
MAX
V
= V
= V
RS-
= 5.5V,
CC
RS+
9
SHDN = GND, T = +25°C
A
Shutdown Supply Current
I
CC SHDN
V
= V
RS+
= V = 24V,
RS-
CC
SHDN = GND
10
30
Leakage Current
Input Bias Current
V
= V
RS-
= 24V, V
= 0V
= 24V
0.1
2.4
75
0.5
5
µA
µA
RS+
CC
I
, I
V
= V = V
RS+ RS-
0
RS+ RS-
CC
Gain = 50V/V
Gain = 100V/V
Recommended Full-Scale Sense
Voltage (Note 6)
V
mV
SENSE
50
Maxim Integrated
│ 2
www.maximintegrated.com
MAX4069–MAX4072
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
Electrical Characteristics (continued)
(V
= V
= V
= 2.7V to 24V, V
= V
- V
= 0V, I
= 0, V
= V , V
= GND, V
= 2.5V
RS+
RS-
CC
SENSE
RS+
RS-
REFOUT
SHDN
CC
GSEL
= V
REFIN
(MAX4072), T = T
to T
, unless otherwise noted. Typical values are at T = +25°C and at V
= 12V.) (Notes 1, 2)
A
MIN
MAX
A
CC
RS+
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
±1.0
±1.5
±2.0
±1.0
±1.5
±2.5
UNITS
T
T
T
T
T
T
= +25°C
±0.25
±0.25
A
A
A
A
A
A
V
V
= 75mV,
SENSE
= V
= 12V,
= -40°C to +85°C
CC
RS+
gain = 50
= T
to T
MAX
MIN
= +25°C
= -40°C to +85°C
= T to T
V
V
= 50mV,
SENSE
= V
= 12V,
CC
RS+
gain = 100
MIN
MAX
MAX4069/MAX4070/
MAX4072:
T
T
T
T
T
T
= +25°C
±0.4
±0.8
±1.0
±2.0
±3.0
±2.0
±4.0
±6
A
A
A
A
A
A
V
V
= -35mV,
= -40°C to +85°C
= T to T
SENSE
= V
= 12V,
CC
RS+
gain = 50
MIN
= +25°C
= -40°C to +85°C
= T to T
MAX
MAX4069/MAX4070/
MAX4072:
Total OUT Voltage Error (Note 7)
%
V
V
= -17.5mV,
SENSE
= V
= 12V,
CC
RS+
gain = 100
MIN
= +25°C
MAX
T
T
T
T
T
T
±1.0
±2.0
±2.5
±4.0
±6.0
±5
MAX4071:
A
A
A
A
A
A
V
V
= -15mV,
SENSE
= V
= -40°C to +85°C
= 12V,
CC
RS+
gain = 50
= T
to T
MAX
MIN
= +25°C
MAX4071:
V
V
= -7.5mV,
SENSE
= V
= -40°C to +85°C
= T to T
±10
±15
= 12V,
CC
RS+
gain = 100
MIN
MAX
V
V
V
= 3mV,
= 12V,
= 12V
SENSE
T
= +25°C
±3
CC
A
RS+
Maxim Integrated
│ 3
www.maximintegrated.com
MAX4069–MAX4072
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
Electrical Characteristics (continued)
(V
= V
= V
= 2.7V to 24V, V
= V
- V
= 0V, I
= 0, V
= V , V
= GND, V
= 2.5V
RS+
RS-
CC
SENSE
RS+
RS-
REFOUT
SHDN
CC
GSEL
= V
REFIN
(MAX4072), T = T
to T
, unless otherwise noted. Typical values are at T = +25°C and at V
= 12V.) (Notes 1, 2)
A
MIN
MAX
A
CC
RS+
PARAMETER
SYMBOL
CONDITIONS
MAX4071,
= 2.7V
= 10µA,
MIN
TYP
MAX
UNITS
65
65
90
90
5
150
V
CC
I
V
V
OUT
= 100mV,
= V
CC
SENSE
MAX4069/MAX4070/
MAX4072,
RS+
150
250
250
20
V
= 3.6V
CC
MAX4071,
= 2.7V
OUT Voltage High
V
- V
OH
mV
CC
V
CC
I
V
V
= 500µA,
= 100mV,
OUT
SENSE
MAX4069/MAX4070/
MAX4072,
= V
CC
RS+
V
= 3.6V
CC
MAX4071,
= 2.7V
V
CC
I
V
V
= -10µA,
= -100mV,
OUT
SENSE
MAX4069/MAX4070/
MAX4072,
= V
CC
RS+
5
20
V
= 3.6V
CC
MAX4071,
= 2.7V
OUT Voltage Low
V
mV
OL
100
100
250
250
V
CC
I
V
V
= -500µA,
= -100mV,
OUT
SENSE
MAX4069/MAX4070/
MAX4072,
= V
CC
RS+
V
= 3.6V
CC
V
V
= 50mV,
= 12V,
Gain = 50V/V
Gain = 100V/V
100
40
SENSE
-3dB Bandwidth
BW
kHz
CC
C = 100pF
L
GSEL = GND
50
Gain
A
V/V
pF
V
GSEL = V
CC
100
100
Capacitive-Load Stability
V
= 2.7V to 24V
CC
(MAX4069/MAX4071/MAX4072),
Power-Supply Rejection Ratio
PSRR
100
2
120
dB
V
V
V
= 3.6V to 24V (MAX4070)
CC
CC
CC
V
= 3.6V or 24V
0.6
V
V
Logic Low Voltage (GSEL, SHDN)
Logic High Voltage (GSEL, SHDN)
Gain-Select Input Current
IL
V
= 3.6V or 24V
IH
I
GSEL = V
CC
= 24V or GND
= 24V
0.01
3
1
12
1
µA
GSEL
SHDN = V
CC
Shutdown Input Current
µA
I
SHDN
0.01
SHDN = GND, V
CC
= 24V
Maxim Integrated
│ 4
www.maximintegrated.com
MAX4069–MAX4072
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
Electrical Characteristics (continued)
(V
= V
= V
= 2.7V to 24V, V
= V
- V
= 0V, I
= 0, V
= V , V
= GND, V
= 2.5V
RS+
RS-
CC
SENSE
RS+
RS-
REFOUT
SHDN
CC
GSEL
= V
REFIN
(MAX4072), T = T
to T
, unless otherwise noted. Typical values are at T = +25°C and at V
= 12V.) (Notes 1, 2)
A
MIN
MAX
A
CC
RS+
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
REFOUT (MAX4069/MAX4070/MAX4071)
MAX4069,
= 12V
(Note 2)
T
T
= +25°C
2.44
2.39
2.49
2.54
2.59
A
A
V
CC
= T
to T
MAX
MIN
T
T
T
T
= +25°C
2.45
2.40
1.47
1.44
2.5
1.5
2.55
2.60
1.53
1.56
A
A
A
A
MAX4070,
Reference Output Voltage
V
V
REF
V
= 12V
CC
= T
to T
MIN
= +25°C
= T to T
MAX
MAX
MAX4071,
V
V
= 12V
= 12V
CC
CC
MIN
-40°Cꢀ≤ꢀT ꢀ≤ꢀ+85°C
15
20
2
A
Reference Output Voltage
TemperatureꢀCoefficient
TCV
ppm/°C
mV/mA
REF
T
= T
to T
MIN MAX
A
I
I
= 0 to 500µA
REFOUT
REFOUT
∆V
REFOUT
/∆I
Load Regulation
REF
= 0 to -100µA
4
∆V
REF
/
Line Regulation
2.7Vꢀ≤ꢀV ꢀ≤ꢀ24Vꢀ
CC
20
µV/V
pF
∆V
CC
REF Capacitive-Load Stability
500
Reference Adjust Voltage
Threshold
V
MAX4069, V
= 12V
CC
1.230
V
ADJ
MAX4069, range adjustable with R1 and
R2, V = 12V
V
ADJ
to +4
Reference Output Voltage Range
V
CC
MAX4069, V
Reference Adjust Input Current
REFIN (MAX4072 ONLY)
Input-Voltage Range
Input Current
I
= 12V, V
CC ADJ
= 1.23V
100
nA
ADJ
V
= 12V
1
4
V
CC
REFIN = 2.5V, V
= 12V
-60
+20
µA
CC
Note 1: All devices are 100% tested at T = +25°C. Limits over temperature are guaranteed by design.
A
Note 2: R1ꢀ=ꢀ215kΩ,ꢀR2ꢀ=ꢀ210kΩꢀforꢀtheꢀMAX4069ꢀonlyꢀ(seeꢀFunctional Diagram). This sets REFOUT to 2.49V nominal.
Note 3: Guaranteed by the PSRR test.
Note 4: The REFOUT voltage for the MAX4069 should be set such that it does not exceed V
- 1.1V. Similarly, the maximum
CC
REFIN voltage for the MAX4072 should also be less than V
- 1.1V.
CC
Note 5: Input-Referred Offset Voltage is defined as the voltage difference between OUT and REFOUT, divided by the selected gain
of either 50 or 100, when V = V - V = 0V.
SENSE
RS+
RS-
Note 6: The negative full-scale sense voltage is limited by the voltage range of OUT from V
to GND.
REFOUT
Note 7: Total OUT Voltage Error is the sum of offset voltage and gain errors. The output voltage is measured relative to the
reference (REFOUT or REFIN).
Maxim Integrated
│ 5
www.maximintegrated.com
MAX4069–MAX4072
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
Typical Operating Characteristics
(V
= V
= 12V, V = 50mV for gain of 100V/V and 75mV for gain of 50V/V, T = +25°C, unless otherwise noted.)
SENSE A
CC
RS+
INPUT OFFSET VOLTAGE
vs. TEMPERATURE
INPUT OFFSET VOLTAGE DISTRIBUTION
(V - V ) vs. V
OUT REF SENSE
150
125
100
75
12
11
10
9
35
A
V
= 100V/V
30
25
20
15
10
5
A
V
= 100V/V
50
8
25
7
0
6
-25
-50
-75
-100
-125
-150
5
4
3
A = 50V/V
V
2
1
0
0
-50 -25
0
25
50
75 100 125
0
25 50 75 100 125 150 175 200 225 250
(V)
TEMPERATURE (°C)
V
SENSE
V
OS
(µV)
TOTAL ERROR vs. SUPPLY VOLTAGE
TOTAL ERROR vs. SUPPLY VOLTAGE
(V
SENSE
= 3mV)
TOTAL ERROR vs. TEMPERATURE
0.5
0.4
0.3
0.2
0.1
0
2.0
1.5
1.0
0.5
0
1.5
1.0
0.5
0
V
= 50mV
= 100V/V
SENSE
A
V
V
A
= 75mV
= 50V/V
SENSE
V
CC
= 24V
V
A
V
= 100V/V
V
= 12V
CC
-0.1
-0.2
-0.3
-0.4
-0.5
-0.5
-1.0
-1.5
-2.0
-0.5
-1.0
-1.5
V
A
= 50mV
= 100V/V
SENSE
V
A
= 50V/V
14
V
4
6
8
10 12 14 16 18 20 22 24
SUPPLY VOLTAGE (V)
2
6
10
18
22
-50 -25
0
25
50
75 100 125
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
MAX4069
SUPPLY CURRENT vs. SUPPLY VOLTAGE
SUPPLY CURRENT vs. TEMPERATURE
REFOUT vs. TEMPERATURE
140
130
120
110
100
90
180
160
140
120
100
80
1.250
1.245
1.240
1.235
1.230
1.225
1.220
1.215
1.210
1.205
1.200
A
V
= 100V/V
REFOUT CONNECTED TO ADJ
A
V
= 50V/V
MAX4071
MAX4070
V
CC
= 24V
MAX4069
V
CC
= 12V
MAX4072
80
60
70
60
40
2
4
6
8
10 12 14 16 18 20 22 24
-50 -25
0
25
50
75 100 125
-50 -25
0
25
50
75 100 125
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
TEMPERATURE (°C)
Maxim Integrated
│ 6
www.maximintegrated.com
MAX4069–MAX4072
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
Typical Operating Characteristics (continued)
(V
= V
= 12V, V
= 50mV for gain of 100V/V and 75mV for gain of 50V/V, T = +25°C, unless otherwise noted.)
CC
RS+
SENSE A
MAX4069
REFOUT vs. SUPPLY VOLTAGE
MAX4070
REFOUT vs. TEMPERATURE
MAX4071
REFOUT vs. TEMPERATURE
1.525
1.520
1.515
1.510
1.505
1.500
1.495
1.490
1.485
1.480
1.475
1.235
1.233
1.231
1.229
1.227
1.225
1.223
1.221
1.219
1.217
1.215
2.540
2.525
2.510
2.495
2.480
2.465
2.450
-50 -25
0
25
50
75 100 125
-50 -25
0
25
50
75 100 125
2
4
6
8
10 12 14 16 18 20 22 24
TEMPERATURE (°C)
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
MAX4070
MAX4071
REFOUT vs. SUPPLY VOLTAGE
REFOUT vs. SUPPLY VOLTAGE
V
vs. TEMPERATURE
OH
= V - V
OUT
2.500
2.499
2.498
2.497
2.496
2.495
2.494
2.493
2.492
2.491
2.490
1.502
1.501
1.500
1.499
1.498
1.497
1.496
1.495
200
180
160
140
120
100
80
V
OH
CC
I = 500µA
L
60
40
I = 10µA
L
20
0
2
4
6
8
10 12 14 16 18 20 22 24
2
6
10
14
18
22
-50 -25
0
25
50
75 100 125
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
SMALL-SIGNAL GAIN
vs. FREQUENCY
V
OL
vs. TEMPERATURE
PSRR AND CMRR vs. FREQUENCY
250
225
200
175
150
125
100
75
5
0
0
-20
-40
-60
A
V
= 50V/V
V
-5
I
= 500µA
CMRR
L
-80
-10
-15
-20
A
= 100V/V
-100
PSRR
50
I
= 10µA
50
L
-120
-140
25
0
-50 -25
0
25
75 100 125
0.1
1
10
FREQUENCY (kHz)
100
1000
0.01
0.1
1
10
100
TEMPERATURE (°C)
FREQUENCY (Hz)
Maxim Integrated
│ 7
www.maximintegrated.com
MAX4069–MAX4072
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
Typical Operating Characteristics (continued)
(V
= V
= 12V, V
= 50mV for gain of 100V/V and 75mV for gain of 50V/V, T = +25°C, unless otherwise noted.)
CC
RS+
SENSE A
SMALL-SIGNAL TRANSIENT RESPONSE
SMALL-SIGNAL TRANSIENT RESPONSE
LARGE-SIGNAL TRANSIENT RESPONSE
MAX4069-72 toc19
MAX4069-72 toc20
MAX4069-72 toc21
GAIN = 100
GAIN = 50
GAIN = 50
INPUT
INPUT
INPUT
5mV/div
5mV/div
50mV/div
OUTPUT
2V/div
OUTPUT
200mV/div
OUTPUT
500mV/div
REF
REF
REF
100µs/div
100µs/div
100µs/div
LARGE-SIGNAL TRANSIENT RESPONSE
STARTUP DELAY
EXITING SHUTDOWN
MAX4069-72 toc22
MAX4069-72 toc23
MAX4069-72 toc24
GAIN = 100
V
CC
V
SHDN
10V/div
5V/div
INPUT
20mV/div
V
OUT
V
OUT
5V/div
2V/div
OUTPUT
2V/div
V
V
REFOUT
2V/div
REFOUT
5V/div
REF
100µs/div
20µs/div
100µs/div
Maxim Integrated
│ 8
www.maximintegrated.com
MAX4069–MAX4072
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
Pin Description
PIN
NAME
FUNCTION
MAX4070/
MAX4071
MAX4069
MAX4072
Shutdown Input. Drive SHDN low to select shutdown mode. Connect SHDN
1
1
1
SHDN
to V
for normal operation.
CC
2
3
4
2
3
2
3
RS-
RS+
N.C.
Negative Connection to the External Sense Resistor
Positive Connection to the External Sense Resistor
No Connection. Not internally connected.
—
—
Ground. For thin QFN packages, also make an external connection from
GND to the under-side exposed paddle.
5
4
4
GND
ADJ
Adjustable Output Voltage Feedback Input. Connect a resistor-divider
between REFOUT, ADJ, and GND (MAX4069 only,
see Functional Diagram).
6
7
8
—
5
—
—
6
REFOUT Reference Output Voltage (MAX4069/MAX4070/MAX4071)
Voltage Output. The difference voltage, V - V , is proportional to
OUT
REF
6
OUT
the voltage difference between RS+ and RS- and indicates the correct
polarity.
9
7
8
7
8
5
V
Supply Voltage Input. Bypass V
to GND with a 0.1µF capacitor.
CC
CC
Gain-Setting Input. Connect GSEL low to select gain = 50V/V, or connect
GSEL high to select gain = 100V/V.
10
—
GSEL
—
REFIN
Reference Input Voltage (MAX4072)
Functional Diagram
2.7V TO 24V
LOAD
V
CC
FROM BATTERY
CHARGER
RS+
MAX4069
OUT
TO ADC
CSA
R
SENSE
RS-
GSEL
GAIN SELECT
SHUTDOWN
OA
REFOUT
ADJ
SHDN
V
1.23V
REF
R1
R2
GND
Maxim Integrated
│ 9
www.maximintegrated.com
MAX4069–MAX4072
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
Detailed Description
R
SENSE
The MAX4069–MAX4072 bidirectional, high-side, cur-
rent-sense amplifiers are ideal for portable equipment.
The wide 1.35V to 24V input common-mode voltage
range is independent of the supply voltage, ensuring that
the current-sense feedback remains accurate even when
connected to a battery pack in deep discharge.
RS+
RG1
RS-
MAX4069–MAX4072
RG2
The MAX4069/MAX4071/MAX4072 operate from a 2.7V
to 24V single supply. Because the MAX4070 has a
2.5V internal reference, it operates from 3.6V to 24V. All
devices have a low 100µA supply current that reduces to
only 10µA (typ) in shutdown mode. To achieve maximum
flexibility, an external current-sense resistor is used along
with a gain select pin (GSEL) to choose either 50V/V or
100V/V. Drive GSEL low to select gain of 50V/V or drive
GSEL high to choose gain of 100V/V (see Functional
Diagram). The MAX4069 has an adjustable reference
voltage set by two external resistors between REFOUT
and ADJ, and GND pins. The MAX4070 contains an
internal 2.5V reference. The MAX4071 is similar to the
MAX4070 but with a fixed internal reference voltage of
1.5V. The MAX4072 has a reference input pin to allow use
of external references. Charging current is represented
OUT
A1
I
OUT
A2
Q1
Q2
Figure 1. Detailed Input Stage
Applications Information
Bidirectional, Current-Sense Amplifier
Systems such as laptop computers and other devices that
have internal charge circuitry require a precise bidirec-
tional, current-sense amplifier to accurately monitor the
battery’s current regardless of polarity. Figure 2 shows
the MAX4069–MAX4072 used as a bidirectional current
by an output voltage from the reference voltage to V
,
CC
while discharge current is given from the reference volt-
age to GND. The direction of V is totally arbitrary.
SENSE
The input stage of the MAX4069–MAX4072 is shown in
Figure 1. Its unique topology allows for monitoring bidi-
monitor. In Figure 2, the direction of V
is assigned
SENSE
to charge and discharge, assuming charge is greater than
discharge. The practical choice of direction is based on
dynamic range at OUT, given that the range of REF to V
is usually greater than from REF to ground. This is useful
for implementing either smart battery packs or fuel gauges.
rectional currents through the sense resistor (R
).
SENSE
If, for instance, current flows from RS+ to RS-, the
MAX4069–MAX4072 match for the voltage drop over the
CC
external sense resistor(R
) by increasing the cur-
SENSE
rent through the internal Q1 and RG1. At the same time,
the current through Q2 and RG2 decreases, however,
internal circuitry not shown in Figure 1 prevents Q2 from
turning off completely. Likewise, if current flows from RS-
to RS+, the current through Q2 and RG2 increases and
the current through Q1 decreases. In this way, the volt-
ages at the input terminals of the internal amplifier A1 are
kept constant and an accurate measurement of the sense
voltage is achieved. In the following amplifier stages of
the MAX4069–MAX4072, the output signal of amplifier
High-Current Measurement
The MAX4069–MAX4072 can achieve high-current mea-
surements by using low-value sense resistors, which can
be paralleled to further increase the current-sense limit.
Adjusting V
(MAX4069)
REF
The MAX4069 has an output reference voltage that
can be set to a desired voltage by a two-resistor divider
between REFOUT, ADJ, and GND. If REFOUT and ADJ
are connected together, the minimum output reference
voltage is obtained, 1.23V (typ). The maximum voltage
A2 is level-shifted towards the reference voltage (V
),
REF
resulting in a voltage at the output pin (OUT) that swings
above the V voltage for positive-sense voltages and
REF
for REFOUT is 4V (that requires V ꢀ≥ꢀ5.1V).ꢀTheꢀrec-
CC
below V
for negative-sense voltages.
REF
ommended range for the external resistors is: R1 + R2
should be > 20kΩꢀandꢀ<ꢀ500kΩ.
Note: R = R = 104k (typ).
G1
G2
Maxim Integrated
│ 10
www.maximintegrated.com
MAX4069–MAX4072
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
I
CHARGE
R
SENSE
I
DISCHARGE
5V
A
= 100
V
V
OUT
- V
REF
RS-
RS+
LOAD
CHARGE
CURRENT
2.5V
V
CC
2
CELLS
MAX4070
GSEL
SHDN
OUT
TO ADC
-25mV
0
25mV
50mV
V
SENSE
REFOUT
2.5V
DISCHARGE
CURRENT
-2.5V
GND
Figure 2. Bidirectional Current Monitor
The MAX4069–MAX4072 sense a wide variety of currents
with different sense-resistor values. Table 1 lists common
resistor values for typical operation of these devices.
Listed output voltage is with respect to REF.
External Reference (MAX4072)
The MAX4072 contains REFIN pin for external reference
voltage. The allowable voltage range on REFIN is 1V
(min) to 4V (max) with V ꢀ≥ꢀ5.1V.
CC
Sense Resistor, R
SENSE
based on the following criteria:
Reference Output
(MAX4069/MAX4060/MAX4071)
Choose R
SENSE
The REFOUT of the MAX4069/MAX4070/MAX4071 can
sink 100µA and source 500µA. Keep the total capacitance
on REFOUT under 500pF to maintain stability.
Voltage Loss: A high R
source voltage to degrade through IR loss. For minimal
voltage loss, use the lowest R value.
value causes the power-
SENSE
SENSE
Accuracy: A high R
to be measured more accurately. This is because offsets
become less significant when the sense voltage is larger.
For best performance, select R
mately 75mV (gain of 50V/V) or 50mV (gain of 100V/V) of
sense voltage for the full-scale current in each application.
value allows lower currents
SENSE
Recommended Component Values
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:
to provide approxi-
SENSE
V
OUT
= V x A
SENSE V
Efficiency and Power Dissipation: At high-current lev-
where V
is the full-scale sense voltage, 75mV for
2
SENSE
els, the I R losses in R
can be significant. Take
SENSE
gain of 50V/V, or 50mV for gain of 100V/V. A is the gain
of the device.
V
this into consideration when choosing the resistor value
and its power dissipation (wattage) rating. Also, the
sense resistor’s value might drift if it is allowed to heat up
excessively.
In applications monitoring high current, ensure that
2
R
is able to dissipate its own I R loss. If the resis-
SENSE
tor’s 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 maximum ratings.
Use resistors specified for current-sensing applications.
Inductance: Keep inductance low if I
has a
SENSE
large high-frequency component. Wire-wound resistors
have the highest inductance, while metal film is some-
what better. Low-inductance metal-film resistors are
also available. Instead of being spiral-wrapped round a
Maxim Integrated
│ 11
www.maximintegrated.com
MAX4069–MAX4072
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
Table 1. Recommended Component Values
FULL-SCALE
CURRENT-SENSE
CURRENT
FULL-SCALE OUTPUT
VOLTAGE WITH RESPECT
TO REF (V)
GAIN
(V/V)
V
SENSE
(mV)
RESISTOR (mΩ)
(A)
0.075
1000
0.05
50
100
50
75
50
75
50
75
50
75
50
75
50
3.75
5.0
0.75
100
0.5
3.75
5.0
100
50
3.75
3.75
5.0
20
2.5
100
50
7.5
3.75
5.0
10
5.0
100
50
15.0
3.75
5.0
5
10.0
100
core, as in metal-film or wire-wound resistors, they are
a straight band of metal and are available in values
under 1Ω.
Power-Supply Bypassing
and Grounding
The MAX4069–MAX4072 do not require special bypassing
and respond quickly to transient changes in line current. You
can place a large capacitor at the RS- terminal (or “load”
side) to decouple the load and, thereby, reduce the current
transients. These capacitors are not required for operation
or stability and their use does not degrade performance.
Peak Current: The maximum current through R
SENSE
must be limited to:
I
= 0.3V / (R
+ R
)
PEAK
SENSE
TRACE
where R
is the total stray resistance from RS+ and
TRACE
RS- to R
To prevent forwarding the back-to-back
SENSE.
diodes between the differential input, the absolute maxi-
mum of the differential input voltage is 0.3V.
The MAX4069–MAX4072 have been designed as a high-
side current monitor to ease the task of grounding any
battery charger, thermistor, etc., that may be a part of
the battery pack. Grounding these devices requires no
special precautions; follow the same cautionary steps
that apply to the system as a whole. High-current sys-
tems can experience large voltage drops across a ground
Dynamic Range Considerations
Although the MAX4069–MAX4072 have fully symmetri-
cal, bidirectional, V
input capability, the output-volt-
SENSE
age range is usually higher from REF to V
and lower
CC
plane, and this drop may add to or subtract from V
.
from REF to GND (unless the supply voltage is at the
lowest end of the operating range). Therefore, the user
must consider the dynamic range of current monitored
in both directions and choose the supply voltage and the
reference voltage (REFOUT or REFIN) to make sure the
output swing above and below REF is adequate to handle
the swings without clipping or running out of headroom.
OUT
Using differential measurement between V
and REF
OUT
prevents this problem. For highest current-measurement
accuracy, use a single-point star ground.
On thin QFN packages, there is an exposed paddle that
does not carry any current, but should also be connected
to the ground plane for rated power dissipation.
Shutdown Mode
When SHDN is low, the MAX4069–MAX4072 are shut
down and consume only 10µA. In shutdown mode, OUT
is high impedance and turns off. Connect SHDN to V
CC
for normal operation.
Maxim Integrated
│ 12
www.maximintegrated.com
MAX4069–MAX4072
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
Pin Configurations
TOP VIEW
+
+
SHDN
RS-
1
2
3
4
8
7
6
5
GSEL
SHDN
RS-
1
2
3
4
5
10 GSEL
9
8
7
6
V
MAX4070
MAX4071
MAX4072
CC
V
CC
MAX4069
µMAX
RS+
N.C.
GND
OUT
RS+
OUT
REFOUT
ADJ
GND
REFOUT (REFIN)
Thin QFN/µMAX
(REFIN) FOR MAX4072 ONLY.
Layout
Selector Guide
In order to dissipate sense-resistor heat from large sense
currents, solder the RS+ and the RS- pins to large copper
traces. Keep the part away from other heat-generating
devices.
SUPPLY
VOLTAGE
RANGE (V)
COMMON-
MODE RANGE
(V)
PART
REFERENCE
MAX4069
MAX4070
MAX4071
MAX4072
ADJUSTABLE
2.5V
2.7 to 24
3.6 to 24
2.7 to 24
2.7 to 24
1.35 to 24
1.35 to 24
1.35 to 24
1.35 to 24
For accurate measurement of V
, the Kelvin method
SENSE
is recommended. The current into RS+ and RS- is only a
few microamps; therefore, a short distance from RS+ and
RS- pins does not cause significant errors. It is recom-
1.5V
EXTERNAL
mended to keep the value of R
reasonably higher
SENSE
than the values of the trace’s resistance.
Chip Information
TRANSISTOR COUNT: 338
PROCESS: BiCMOS
Package Information
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 TYPE
8 TQFN-EP
8ꢀμMAX
PACKAGE CODE
T833-2
DOCUMENT NO.
21-0137
U8-1
21-0036
10ꢀμMAX
U10-2
21-0061
Maxim Integrated
│ 13
www.maximintegrated.com
MAX4069–MAX4072
Bidirectional, High-Side, Current-Sense
Amplifiers with Reference
Revision History
REVISION REVISION
PAGES
CHANGED
DESCRIPTION
NUMBER
DATE
11/08
11/16
3
4
Added information for RG1 and RG2
10
1
Updated Ordering Information table
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.
│ 14
相关型号：
MAX406ACPA+
Operational Amplifier, 1 Func, 950uV Offset-Max, CMOS, PDIP8, 0.300 INCH, PLASTIC, MS-001AB, DIP-8
MAXIM
MAX406ACSA-T
Operational Amplifier, 1 Func, 950uV Offset-Max, CMOS, PDSO8, 0.150 INCH, MS-012AA, SOIC-8
MAXIM
MAX406AEPA+
Operational Amplifier, 1 Func, 1100uV Offset-Max, CMOS, PDIP8, 0.300 INCH, PLASTIC, MS-001AB, DIP-8
MAXIM
MAX406AESA-T
Operational Amplifier, 1 Func, 1100uV Offset-Max, CMOS, PDSO8, 0.150 INCH, MS-012AA, SOIC-8
MAXIM
©2020 ICPDF网 联系我们和版权申明