MAX44244AUA+ [MAXIM]
36V, Precision, Low-Power, 90μA, Single/Quad/Dual Op Amps;型号: | MAX44244AUA+ |
厂家: | MAXIM INTEGRATED PRODUCTS |
描述: | 36V, Precision, Low-Power, 90μA, Single/Quad/Dual Op Amps |
文件: | 总14页 (文件大小:954K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
EVALUATION KIT AVAILABLE
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MAX44244/MAX44245/
MAX44248
36V, Precision, Low-Power, 90μA,
Single/Quad/Dual Op Amps
General Description
Benefits and Features
● Reduces Power for Sensitive Precision Applications
The MAX44244/MAX44245/MAX44248 family of parts
provide ultra-precision, low-noise, zero-drift single/quad/
dual operational amplifiers featuring very low-power
operation with a wide supply range. The devices
incorporate a patented auto-zero circuit that constantly
measures and compensates the input offset to eliminate
drift over time and temperature as well as the effect of 1/f
noise. These devices also feature integrated EMI filters
to reduce high-frequency signal demodulation on the
output. The op amps operate from either a single 2.7V to
36V supply or dual ±1.35V to ±18V supply. The devices
are unity-gain stable with a 1MHz gain-bandwidth product
and a low 90µA supply current per amplifier.
• Low 90µA Quiescent Current per Amplifier
● Eliminates the Cost of Calibration with Increased
Accuracy with Maxim’s Patented Autozero Circuitry
• Very Low Input Voltage Offset 7.5µV (max)
• Low 30nV/°C Offset Drift (max)
● Low Noise Ideal for Sensor Interfaces and
Transmitters
• 50nV/√Hz at 1kHz
• 0.5µV
from 0.1Hz to 10Hz
P-P
● 1MHz Gain-Bandwidth Product
• EMI Suppression Circuitry
The low offset and noise specifications and high supply
range make the devices ideal for sensor interfaces and
transmitters.
● Rail-to-Rail Output
● Wide Supply for High-Voltage Front Ends
• 2.7V to 36V Supply Range
®
The devices are available in µMAX , SO, SOT23, and
● µMAX, SO, SOT23, TSSOP Packages
TSSOP packages and are specified over the -40°C to
+125°C automotive operating temperature range.
Ordering Information appears at end of data sheet.
Applications
● Sensors Interfaces
● 4mA to 20mA and 0 to10V Transmitters
● PLC Analog I/O Modules
● Weight Scales
● Portable Medical Devices
μMAX is a registered trademark of Maxim Integrated Products, Inc.
Typical Operating Circuit
LP+
V
REF
MAX6033
REF
I
SIG
R1
(4-20mA)
R2
MAX5216
DAC
MAX44244
R3
FLOATING
GROUND
R
SENSE
LP-
19-6367; Rev 6; 11/18
MAX44244/MAX44245/
MAX44248
36V, Precision, Low-Power, 90μA,
Single/Quad/Dual Op Amps
Absolute Maximum Ratings
V
to V ............................................................-0.3V to +40V
Operating Temperature Range......................... -40°C to +125°C
Storage Temperature........................................ -65°C to +150°C
Junction Temperature......................................................+150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow).......................................+260°C
DD
SS
Common-Mode Input Voltage........(V - 0.3V) to (V
Differential Input Voltage IN_+, IN_- ......................................6V
Continuous Input Current Into Any Pin.............................±20mA
+ 0.3V)
SS
DD
Output Voltage to V (OUT_)............... – 0.3V to (V
+ 0.3V)
SS
DD
Output Short-Circuit Duration (OUT_)..................................... 1s
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
SO-8
TSSOP
Junction-to-Ambient Thermal Resistance (θ ) ........110°C/W
Junction-to-Ambient Thermal Resistance (θ ) ........132°C/W
JA
JA
Junction-to-Case Thermal Resistance (θ )...............38°C/W
Junction-to-Case Thermal Resistance (θ )...............30°C/W
JC
JC
SO-14
µMAX
Junction-to-Ambient Thermal Resistance (θ ) ........120°C/W
Junction-to-Ambient Thermal Resistance (θ ) .....206.3°C/W
JA
JA
Junction-to-Case Thermal Resistance (θ )...............37°C/W
Junction-to-Case Thermal Resistance (θ )...............42°C/W
JC
JC
SOT23
Junction-to-Ambient Thermal Resistance (θ ) .....324.3°C/W
JA
Junction-to-Case Thermal Resistance (θ )...............82°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
= 10V, V
= 0V, V
= V
= V /2, R = 5kΩ to V /2, T = -40°C to +125°C, unless otherwise noted. Typical values are
DD
SS
IN+
IN-
DD
L
DD
A
at +25°C.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
POWER SUPPLY
Supply Voltage Range
V
Guaranteed by PSRR
T = +25°C, V = V = V /2 - 1V
2.7
140
133
36
V
DD
148
100
90
A
IN+
IN-
DD
Power-Supply Rejection Ratio
(Note 3)
PSRR
dB
-40°C < T < +125°C
A
T = +25°C
160
190
130
145
A
Quiescent Current Per Amplifier
(MAX4244 Only)
I
I
µA
µA
DD
DD
-40°C < T < +125°C
A
T = +25°C
A
Quiescent Current Per Amplifier
(MAX44245/MAX44248 Only)
-40°C < T < +125°C
A
DC SPECIFICATIONS
V
0.05
-
V
1.5
-
DD
SS
Input Common-Mode Range
V
CM
Guaranteed by CMRR test
V
Maxim Integrated
│ 2
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MAX44244/MAX44245/
MAX44248
36V, Precision, Low-Power, 90μA,
Single/Quad/Dual Op Amps
Electrical Characteristics (continued)
(V
= 10V, V
= 0V, V
= V
= V /2, R = 5kΩ to V /2, T = -40°C to +125°C, unless otherwise noted. Typical values are
DD
SS
IN+
IN-
DD
L
DD
A
at +25°C.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
T
V
= +25°C, V
= V - 0.05V to
A
CM SS
126
130
- 1.5V
DD
Common-Mode Rejection Ratio
(Note 3)
CMRR
dB
-40°C < T < +125°C, V
= V - 0.05V
SS
A
CM
120
to V
- 1.5V
DD
T
= +25°C
2
7.5
10
A
Input Offset Voltage (Note 3)
V
µV
nV/°C
pA
OS
-40°C < T < +125°C
A
Input Offset Voltage Drift
(Note 3)
TC V
10
30
OS
T = +25°C
150
300
700
A
Input Bias Current (Note 3)
Input Offset Current (Note 3)
I
B
-40°C < T < +125°C
A
T = +25°C
300
150
600
A
I
pA
OS
-40°C < T < +125°C
1400
A
V
V
0.5V
+ 0.5V ≤
T
= +25°C
140
135
SS
A
Open-Loop Gain (Note 3)
A
≤ V -
DD
dB
VOL
OUT
-40°C < T < +125°C
A
Output Short-Circuit Current
To V
or V , noncontinuous
40
mA
DD
SS
T = +25°C
80
110
50
A
V
V
-
DD
OUT
-40°C < T < +125°C
A
Output Voltage Swing
mV
T = +25°C
A
V
-
OUT
V
SS
-40°C < T < +125°C
A
75
AC SPECIFICATIONS
Input Voltage-Noise Density
Input Voltage Noise
e
f = 1kHz
50
500
0.1
1
nV/√Hz
N
0.1Hz < f < 10Hz
f = 1kHz
nV
P-P
Input Current-Noise Density
Gain-Bandwidth Product
Slew Rate
i
pA/√Hz
MHz
V/µs
pF
N
GBW
SR
A
V
= 1V/V, V
= 2V
P-P
0.7
400
OUT
Capacitive Loading
C
No sustained oscillation, A = 1V/V
V
L
Total Harmonic Distortion
Plus Noise
THD+N
EMIRR
V
= 2V , A = +1V/V, f = 1kHz
-100
dB
OUT
P-P
V
f = 400MHz
f = 900MHz
f = 1800MHz
f = 2400MHz
75
78
80
90
EMI Rejection Ratio
V
= 100mV
dB
RF_PEAK
Maxim Integrated
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MAX44244/MAX44245/
MAX44248
36V, Precision, Low-Power, 90μA,
Single/Quad/Dual Op Amps
Electrical Characteristics (continued)
(V
= 30V, V
= 0V, V
= V
= V /2, R = 5kΩ to V /2, T = -40°C to +125°C, unless otherwise noted. Typical values are
DD
SS
IN+
IN-
DD
L
DD
A
at +25°C.) (Note 2)
PARAMETER
POWER SUPPLY
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
T = +25°C
100
160
190
130
145
A
Quiescent Current Per Amplifier
(MAX44244 Only)
I
I
µA
µA
DD
-40°C < T < +125°C
A
T = +25°C
90
A
Quiescent Current Per Amplifier
(MAX44245/MAX44248 Only)
DD
-40°C < T < +125°C
A
DC SPECIFICATIONS
V
0.05
-
V
1.5
-
DD
SS
Input Common-Mode Range
V
Guaranteed by CMRR test
V
CM
T
V
= +25°C, V
= V - 0.05V to
A
CM SS
130
126
140
2
- 1.5V
DD
Common-Mode Rejection Ratio
(Note 3)
CMRR
dB
-40°C < T < +125°C, V
to V
= V - 0.05V
SS
A
CM
- 1.5V
DD
T
= +25°C
7.5
10
A
Input Offset Voltage (Note 3)
V
µV
nV/°C
pA
OS
-40°C < T < +125°C
A
Input Offset Voltage Drift
(Note 3)
TC V
10
30
OS
T = +25°C
150
300
700
600
A
Input Bias Current (Note 3)
Input Offset Current (Note 3)
I
B
-40°C < T < +125°C
A
T = +25°C
300
150
40
A
I
pA
OS
-40°C < T < +125°C
1400
A
T
= +25°C
146
140
V
+ 0.5V ≤ V
A
SS
≤ V
OUT
Open-Loop Gain (Note 3)
A
dB
VOL
- 0.5V
-40°C < T < +125°C
DD
A
Output Short-Circuit Current
To V
or V , noncontinuous
mA
DD
SS
T = +25°C
200
270
140
220
A
V
V
-
DD
OUT
-40°C < T < +125°C
A
Output Voltage Swing
mV
T = +25°C
A
V
-
OUT
V
SS
-40°C < T < +125°C
A
AC SPECIFICATIONS
Input Voltage-Noise Density
Input Voltage Noise
e
f = 1kHz
50
500
0.1
1
nV/√Hz
N
0.1Hz < f < 10Hz
f = 1kHz
nV
P-P
Input Current-Noise Density
Gain-Bandwidth Product
i
pA/√Hz
N
GBW
MHz
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MAX44244/MAX44245/
MAX44248
36V, Precision, Low-Power, 90μA,
Single/Quad/Dual Op Amps
Electrical Characteristics (continued)
(V
= 30V, V
= 0V, V
= V
= V /2, R = 5kΩ to V /2, T = -40°C to +125°C, unless otherwise noted. Typical values are
DD
SS
IN+
IN-
DD
L
DD
A
at +25°C.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
0.7
MAX
UNITS
V/µs
pF
Slew Rate
SR
A
= 1V/V, V
= 2V
V
OUT P-P
Capacitive Loading
C
No sustained oscillation, A = 1V/V
400
L
V
Total Harmonic Distortion
Plus Noise
THD+N
V
OUT
= 2V , A = +1V/V, f = 1kHz
-100
dB
P-P
V
f = 400MHz
f = 900MHz
f = 1800MHz
f = 2400MHz
75
78
80
90
EMI Rejection Ratio
EMIRR
V
= 100mV
dB
RF_PEAK
Note 2: All devices are 100% production tested at T = +25°C. Temperature limits are guaranteed by design.
A
Note 3: Guaranteed by design.
Note 4: At IN+ and IN-. Defined as 20log (V
/ΔV ).
OS
RF_PEAK
Typical Operating Characteristics
(V
= 10V, V = 0V, V
= V = V /2, R = 5kΩ to V /2. Typical values are at T = +25°C.)
DD
SS
IN+ IN- DD L DD A
SUPPLY CURRENT
INPUT OFFSET VOLTAGE HISTOGRAM
INPUT OFFSET VOLTAGE DRIFT
vs. SUPPLY VOLTAGE
45
35
30
25
20
15
10
5
100
98
96
94
92
90
88
86
84
82
80
40
35
30
25
20
15
10
5
0
0
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5
INPUT OFFSET VOLTAGE (µV)
4
5
6
7
8
9
10 11 12 13 14
0
10
20
30
40
INPUT OFFSET VOLTAGE DRIFT (nV/°C)
SUPPLY VOLTAGE (V)
Maxim Integrated
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MAX44244/MAX44245/
MAX44248
36V, Precision, Low-Power, 90μA,
Single/Quad/Dual Op Amps
Typical Operating Characteristics (continued)
(V
= 10V, V = 0V, V
= V = V /2, R = 5kΩ to V /2. Typical values are at T = +25°C.)
DD
SS
IN+ IN- DD L DD A
INPUT OFFSET VOLTAGE
vs. COMMON-MODE VOLTAGE
INPUT OFFSET VOLTAGE
VS. TEMPERATURE
SUPPLY CURRENT
vs. TEMPERATURE
100
2
1
3
2
98
96
94
92
90
88
86
84
82
80
1
0
-1
-2
-3
-4
0
-1
-2
-3
-4
-5
-50 -25
0
25
50
75 100 125
-6
-4
-2
0
2
4
6
-50 -25
0
25
50
75 100 125
TEMPERATURE (°C)
COMMON-MODE VOLTAGE (V)
TEMPERATURE (°C)
INPUT BIAS CURRENT
VS. COMMON-MODE VOLTAGE
INPUT BIAS CURRENT
vs. TEMPERATURE
180
160
140
120
100
80
800
600
400
200
0
60
40
-200
-400
20
0
0
2
4
6
8
10
-50 -25
0
25
50
75 100 125
COMMON-MODE VOLTAGE (V)
TEMPERATURE (°C)
COMMON-MODE REJECTION RATIO
vs. FREQUENCY
COMMON-MODE REJECTION RATIO
vs. TEMPERATURE
0
-20
-100
-105
-110
-115
-120
-125
-130
-135
-40
-60
-80
-100
-120
-140
10
100
1k
10k
100k
1M
-50 -25
0
25
50
75 100 125
FREQUENCY (Hz)
TEMPERATURE (°C)
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MAX44244/MAX44245/
MAX44248
36V, Precision, Low-Power, 90μA,
Single/Quad/Dual Op Amps
Typical Operating Characteristics (continued)
(V
= 10V, V = 0V, V
= V = V /2, R = 5kΩ to V /2. Typical values are at T = +25°C.)
DD
SS
IN+
IN-
DD
L
DD
A
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
OUTPUT VOLTAGE HIGH
vs. TEMPERATURE
OUTPUT VOLTAGE LOW
vs. TEMPERATURE
0
80
70
60
50
40
30
60
50
40
30
20
10
0
-20
-40
-60
-80
-100
-120
-140
-160
20
10
0
10
100
1k
10k
100k
1M
-50 -25
0
25
50
75 100 125
-50 -25
0
25
50
75 100 125
FREQUENCY (Hz)
TEMPERATURE (°C)
TEMPERATURE (°C)
OUTPUT VOLTAGE HIGH
vs. SOURCE CURRENT
OUTPUT VOLTAGE LOW
vs. SINK CURRENT
1000
1000
100
10
100
10
1
1
0.1
1
10
0.1
1
10
SOURCE CURRENT (mA)
SINK CURRENT (mA)
0.1Hz TO 10Hz INPUT VOLTAGE
PEAK-PEAK NOISE
INPUT VOLTAGE NOISE
vs. FREQUENCY
MAX44248 toc17
200
180
160
140
120
100
80
200nV/div
60
40
20
0
10
100
1k
10k
100k
4s/div
FREQUENCY (Hz)
Maxim Integrated
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MAX44244/MAX44245/
MAX44248
36V, Precision, Low-Power, 90μA,
Single/Quad/Dual Op Amps
Typical Operating Characteristics (continued)
(V
= 10V, V = 0V, V
= V = V /2, R = 5kΩ to V /2. Typical values are at T = +25°C.)
DD
SS
IN+ IN- DD L DD A
INPUT CURRENT NOISE
vs. FREQUENCY
SMALL SIGNAL GAIN
vs. FREQUENCY
LARGE SIGNAL GAIN
vs. FREQUENCY
10
25
20
15
10
5
25
20
15
10
5
9
8
7
6
5
4
3
2
1
0
GAIN = 11V/V,
= 200mV
GAIN = 11V/V,
= 2V
V
V
OUT
OUT
PP
PP
0
0
-5
-5
10
100
1k
10k
100k
0.01
0.1
1
10
100 1000 10000
0.01
0.1
1
10
100 1000 10000
FREQUENCY (Hz)
FREQUENCY (kHz)
FREQUENCY (kHz)
LARGE-SIGNAL STEP RESPONSE
SMALL-SIGNAL STEP RESPONSE
MAX44248 toc22
MAX44248 toc21
V
V
IN
2V/div
IN
100mV/div
V
V
OUT
OUT
50mV/div
500mV/div
4µs/div
4µs/div
TOTAL HARMONIC DISTORTION
vs. FREQUENCY
POWER-UP TIME
MAX44248 toc23
0
-20
V
DD
10V/div
-40
R
= 1kΩ
LOAD
-60
R
= 600Ω
LOAD
-80
V
OUT
2V/div
-100
-120
-140
R
LOAD
= 5kΩ
10
100
1k
FREQUENCY (Hz)
10k
100k
20µs/div
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MAX44244/MAX44245/
MAX44248
36V, Precision, Low-Power, 90μA,
Single/Quad/Dual Op Amps
Typical Operating Characteristics (continued)
(V
= 10V, V = 0V, V
= V = V /2, R = 5kΩ to V /2. Typical values are at T = +25°C.)
IN+ IN- DD L DD A
DD
SS
OUTPUT STABILITY
OUTPUT STABILITY
vs. CAPACITIVE LOAD
vs. ISOLATION RESISTANCE
10k
1k
10k
1k
UNSTABLE
STABLE
100
10
100
10
1
STABLE
UNSTABLE
1
100
1000
10,000
100,000
100
1000
10,000
100,000
CAPACITIVE LOAD (pF)
CAPACITIVE LOAD (pF)
CROSSTALK vs. FREQUENCY
OUTPUT IMPEDANCE vs. FREQUENCY
0
-20
1000
100
10
-40
-60
-80
-100
-120
-140
-160
1
0.1
0.01
0.1
1
10
100
1000
0.01
0.1
1
10
100
1000
FREQUENCY (kHz)
FREQUENCY (kHz)
EMIRR vs. FREQUENCY
120
100
80
60
40
20
0
10
100
1,000
10,000
FREQUENCY (MHz)
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MAX44244/MAX44245/
MAX44248
36V, Precision, Low-Power, 90μA,
Single/Quad/Dual Op Amps
Pin Configurations
TOP VIEW
+
OUTA
1
2
3
5
4
V
DD
+
N.C.
INA-
INA+
1
2
3
4
8
7
6
5
N.C.
MAX44244
V
DD
V
MAX44244
SS
OUTA
N.C.
V
SS
INA+
INA-
µMAX
SOT23
+
+
OUTA
INA-
1
2
3
4
5
6
7
14 OUTD
OUTA
INA-
1
2
3
4
5
6
7
14 OUTD
13 IND-
12 IND+
13 IND-
12 IND+
INA+
INA+
MAX44245
MAX44245
V
11
V
SS
DD
V
11 V
SS
DD
INB+
INB-
10 INC+
INB+
INB-
10 INC+
9
8
INC-
9
8
INC-
OUTB
OUTC
OUTB
OUTC
TSSOP
SO-14
+
OUTA
INA-
1
2
3
4
8
7
6
5
V
DD
+
OUTA
1
2
3
4
8
7
6
5
V
DD
MAX44248
OUTB
INB-
INA-
OUTB
INB-
MAX44248
INA+
INA+
V
INB+
SS
µMAX
V
SS
INB+
SO-8
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MAX44244/MAX44245/
MAX44248
36V, Precision, Low-Power, 90μA,
Single/Quad/Dual Op Amps
Pin Description
PIN
MAX44245
MAX44244
MAX44248
NAME
FUNCTION
SOT23
µMAX
6
SO-14
TSSOP
SO-8
µMAX
1
1
2
1
11
3
1
11
3
1
4
OUTA
Channel A Output
4
4
V
Negative Supply Voltage
Channel A Positive Input
Channel A Negative Input
Positive Supply Voltage
Channel B Positive Input
Channel B Negative Input
Channel B Output
SS
3
3
3
3
INA+
INA-
4
2
2
2
2
2
5
7
4
4
8
8
V
DD
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
5
5
5
5
INB+
INB-
6
6
6
6
7
7
7
7
OUTB
OUTC
INC-
8
8
—
—
—
—
—
—
—
—
—
—
—
—
Channel C Output
9
9
Channel C Negative Input
Channel C Positive Input
Channel D Positive Input
Channel D Negative Input
Channel D Output
10
12
13
14
10
12
13
14
INC+
IND+
IND-
OUTD
No Connection. Not internally
connected.
—
1, 5, 8
—
—
—
—
N.C.
Detailed Description
Applications Information
The MAX44244/MAX44245/MAX44248 are high-
precision amplifiers with less than 2µV (typ) input-referred
offset and low input voltage-noise density at 10Hz.
1/f noise, in fact, is eliminated to improve the performance
in low-frequency applications. These characteristics are
achieved through an auto-zeroing technique that cancels
the input offset voltage and 1/f noise of the amplifier.
The devices feature ultra-high precision operational
amplifiers with a high supply voltage range designed
for load cell, medical instrumentation, and precision
instrument applications.
4–20mA Current-Loop Communication
Industrial environments typically have a large amount of
broadcast electromagnetic interference (EMI) from high-
voltage transients and switching motors. This combined
with long cables for sensor communication leads to
high-voltage noise on communication lines. Current-Loop
communication is resistant to this noise because the EMI
induced current is low. This configuration also allows for
low-power sensor applications to be powered from the
communication lines.
External Noise Suppression in EMI Form
These devices have input EMI filters to prevent effects
of radio frequency interference on the output. The EMI
filters comprise passive devices that present significant
higher impedance to higher frequency signals. See the
EMIRR vs. Frequency graph in the Typical Operating
Characteristics section for details.
The Typical Operating Circuit shows how the device can
be used to make a current loop driver.
High Supply Voltage Range
The devices feature 90µA current consumption per chan-
nel and a voltage supply range from either 2.7V to 36V
single supply or ±1.35V to ±18V split supply.
Maxim Integrated
│ 11
www.maximintegrated.com
MAX44244/MAX44245/
MAX44248
36V, Precision, Low-Power, 90μA,
Single/Quad/Dual Op Amps
The circuit uses low-power components such as the
MAX44244 op amp, the 16-bit MAX5216 DAC, and the
high-precision 60µA-only MAX6033 reference. In this
circuit, both the DAC and the reference are referred to
the local ground. The MAX44244 op-amp inputs are
capable of swinging to the negative supply (which is the
local ground in this case). R3 acts as a current mirror with
high dynamic range with low power such as sensors on
a 4–20mA industrial control loop. The devices provide a
high-accuracy internal oscillator that requires no external
components.
Layout Guidelines
The MAX44244/MAX44245/MAX44248 feature ultra-low
input offset voltage and noise. Therefore, to get optimum
performance follow the layout guidelines.
R
. Therefore, if R
= 50Ω (i.e. 20mA will drop
SENSE
SENSE
1V) and if the current through R3 is 10μA when I
is
OUT
20mA (0.05% error) then R3 = 100kΩ. R1 is chosen along
with the reference voltage to provide the 4mA offset. R2
= 512kΩ for 20mA full scale or R2 = 614kΩ for 20% over-
Avoid temperature tradients at the junction of two dissimilar
metals. The most common dissimilar metals used on a
PCB are solder-to-component lead and solder-to-board
trace. Dissimilar metals create a local thermocouple.
A variation in temperature across the board can cause
an additional offset due to Seebeck effect at the solder
junctions. To minimize the Seebeck effect, place the
amplifier away from potential heat sources on the board,
if possible. Orient the resistors such that both the ends
are heated equally. It is a good practice to match the
input signal path to ensure that the type and number of
thermoelectric juntions remain the same. For example,
consider using dummy 0Ω resistors oriented in such a way
that the thermoelectric source, due to the real resistors in
the signal path, are cancelled. It is recommended to flood
the PCB with ground plane. The ground plane ensures
that heat is distributed uniformly reducing the potential
offset voltage degradation due to Seebeck effect.
range. R
is ratiometric with R3, R1 independently
SENSE
sets the offset current and R2 independently sets the
DAC scaling.
Driving High-Performance ADCs
The MAX44244/MAX44245/MAX44248’s low input offset
voltage and low noise make these amplifiers ideal for
ADC buffering. Weight scale applications require a low-
noise, precision amplifier in front of an ADC. Figure 1
details an example of a load cell and amplifier driven from
the same 5V supply, along with a 16-bit delta sigma ADC
such as the MAX11205.
The MAX11205 is an ultra-low-power (< 300μA, max
active current), high-resolution, serial output ADC. It
provides the highest resolution per unit power in the
industry and is optimized for applications that require very
5V
5V
½ MAX44248
AMP A
V
DD
5V
MICRO-
CONTROLLER
R
R
F
V
DD
SCLK
RDY/DOUT
MAX11205
SCK
V
V
IN+
MISO
R
G
F
IN-
V
SS
5V
V
SS
AMP B
½ MAX44248
Figure 1. Weight Application
Maxim Integrated
│ 12
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MAX44244/MAX44245/
MAX44248
36V, Precision, Low-Power, 90μA,
Single/Quad/Dual Op Amps
Chip Information
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.
PROCESS: BiCMOS
Ordering Information
PIN-
TOP
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
PART
TEMP RANGE
PACKAGE MARK
MAX44244AUK+
MAX44244AUA+
MAX44245ASD+
MAX44245AUD+
MAX44248AUA+
MAX44248ASA+
-40°C to +125°C 5 SOT23
-40°C to +125°C 8 µMAX
-40°C to +125°C 14 SO
-40°C to +125°C 14 TSSOP
-40°C to +125°C 8 µMAX
-40°C to +125°C 8 SO
AFMR
—
5 SOT23
8 SO
U5+1
S8+4
21-0057
21-0041
21-0036
21-0041
21-0066
90-0174
90-0096
90-0092
90-0112
90-0113
—
8 µMAX
14 SO
U8+1
—
S14M+4
U14M+1
—
14 TSSOP
—
+Denotes a lead(Pb)-free/RoHS-compliant package.
Maxim Integrated
│ 13
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MAX44244/MAX44245/
MAX44248
36V, Precision, Low-Power, 90μA,
Single/Quad/Dual Op Amps
Revision History
REVISION
NUMBER
REVISION
DATE
PAGES
CHANGED
DESCRIPTION
0
7/12
Initial release
—
Added the MAX44244/MAX44245 to data sheet. Updated the Electrical
Characteristics, Absolute Maximum Ratings, Pin Description, and Pin
Configurations.
1
6/13
1–13
Released the MAX44244 for introduction. Revised the Electrical
Characteristics
2
9/13
2–5, 13
3
4
5
6
6/14
12/14
9/15
Corrected Figure 1 and Package Information
Updated Benefits and Features section
Updated Typical Operating Circuit
12, 13
1
1
11/18
Updated Typical Operating Chracteristics
7–9
For pricing, delivery, and ordering information, please visit Maxim Integrated’s online storefront at https://www.maximintegrated.com/en/storefront/storefront.html.
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.
2018 Maxim Integrated Products, Inc.
│ 14
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