MAX44244/MAX44245/MAX44248
36V, Precision, Low-Power, 90µA,
Single/Quad/Dual Op Amps
Typical Operating Circuit
19-6367; Rev 5; 9/15
General Description
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 incor-
porate a patented auto-zero circuit that constantly mea-
sures 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 prod-
uct and a low 90µA supply current per amplifier.
The low offset and noise specifications and high supply
range make the devices ideal for sensor interfaces and
transmitters.
The devices are available in FMAXM, SO, SOT23, and
TSSOP packages and are specified over the -40NC to
+125NC automotive operating temperature range.
Applications
Sensors Interfaces
4mA to 20mA and 0 to10V Transmitters
PLC Analog I/O Modules
Weight Scales
Portable Medical Devices
Benefits and Features
●Reduces Power for Sensitive Precision Applications
• Low 90µA Quiescent Current per Amplier
●Eliminates the Cost of Calibration with Increased
Accuracy with Maxim’s Patented Autozero Circuitry
• Very Low Input Voltage Offset 7.5µV (max)
• Low 30nV/NC Offset Drift (max)
●Low Noise Ideal for Sensor Interfaces and
Transmitters
• 50nV/√Hz at 1kHz
• 0.5µVP-P from 0.1Hz to 10Hz
●1MHz Gain-Bandwidth Product
• EMI Suppression Circuitry
●Rail-to-Rail Output
●Wide Supply for High-Voltage Front Ends
• 2.7V to 36V Supply Range
●µMAX, SO, SOT23, TSSOP Packages
Ordering Information appears at end of data sheet.
µMAX is a registered trademark of Maxim Integrated Products, Inc.
EVALUATION KIT AVAILABLE
MAX5216
DAC
MAX6033
REF
R1
RSENSE
R3
R2
VREF
LP+
LP-
ISIG
(4-20mA)
MAX44244
FLOATING
GROUND
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
2Maxim Integrated
MAX44244/MAX44245/MAX44248
36V, Precision, Low-Power, 90µA,
Single/Quad/Dual Op Amps
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 opera-
tion 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.
PACKAGE THERMAL CHARACTERISTICS (Note 1)
VDD to VSS ............................................................-0.3V to +40V
Common-Mode Input Voltage ........(VSS - 0.3V) to (VDD + 0.3V)
Differential Input Voltage IN_+, IN_- ......................................6V
Continuous Input Current Into Any Pin ........................... Q20mA
Output Voltage to VSS (OUT_) ................– 0.3V to (VDD + 0.3V)
Output Short-Circuit Duration (OUT_) ..................................... 1s
Operating Temperature Range ........................ -40NC to +125NC
Storage Temperature ....................................... -65NC to +150NC
Junction Temperature .....................................................+150NC
Lead Temperature (soldering, 10s) ................................+300NC
Soldering Temperature (reflow) ......................................+260NC
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
(VDD = 10V, VSS = 0V, VIN+ = VIN- = VDD/2, RL = 5kI to VDD/2, TA = -40NC to +125NC, unless otherwise noted. Typical values are
at +25NC.) (Note 2)
SO-8
Junction-to-Ambient Thermal Resistance (BJA) ........132NC/W
Junction-to-Case Thermal Resistance (BJC) ...............38NC/W
SO-14
Junction-to-Ambient Thermal Resistance (BJA) ........120NC/W
Junction-to-Case Thermal Resistance (BJC) ...............37NC/W
SOT23
Junction-to-Ambient Thermal Resistance (BJA) .....324.3NC/W
Junction-to-Case Thermal Resistance (BJC) ...............82NC/W
TSSOP
Junction-to-Ambient Thermal Resistance (BJA) ........110NC/W
Junction-to-Case Thermal Resistance (BJC) ...............30NC/W
FMAX
Junction-to-Ambient Thermal Resistance (BJA) .....206.3NC/W
Junction-to-Case Thermal Resistance (BJC) ...............42NC/W
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
POWER SUPPLY
Supply Voltage Range VDD Guaranteed by PSRR 2.7 36 V
Power-Supply Rejection Ratio
(Note 3) PSRR TA = +25NC, VIN+ = VIN- = VDD/2 - 1V 140 148 dB
-40NC < TA < +125NC 133
Quiescent Current Per Amplifier
(MAX4244 Only) IDD
TA = +25NC 100 160 FA
-40NC < TA < +125NC 190
Quiescent Current Per Amplifier
(MAX44245/MAX44248 Only) IDD
TA = +25NC 90 130 FA
-40NC < TA < +125NC 145
DC SPECIFICATIONS
Input Common-Mode Range VCM Guaranteed by CMRR test VSS -
0.05
VDD -
1.5 V
3Maxim Integrated
MAX44244/MAX44245/MAX44248
36V, Precision, Low-Power, 90µA,
Single/Quad/Dual Op Amps
ELECTRICAL CHARACTERISTICS (continued)
(VDD = 10V, VSS = 0V, VIN+ = VIN- = VDD/2, RL = 5kI to VDD/2, TA = -40NC to +125NC, unless otherwise noted. Typical values are
at +25NC.) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Common-Mode Rejection Ratio
(Note 3) CMRR
TA = +25NC, VCM = VSS - 0.05V to VDD -
1.5V 126 130
dB
-40NC < TA < +125NC, VCM = VSS - 0.05V
to VDD - 1.5V 120
Input Offset Voltage (Note 3) VOS
TA = +25NC 2 7.5 FV
-40NC < TA < +125NC 10
Input Offset Voltage Drift
(Note 3) TC VOS 10 30 nV/NC
Input Bias Current (Note 3) IB
TA = +25NC 150 300 pA
-40NC < TA < +125NC 700
Input Offset Current (Note 3) IOS
TA = +25NC 300 600 pA
-40NC < TA < +125NC 1400
Open-Loop Gain (Note 3) A VOL
VSS + 0.5V P
VOUT P VDD -
0.5V
TA = +25NC 140 150
dB
-40NC < TA < +125NC 135
Output Short-Circuit Current To VDD or VSS, noncontinuous 40 mA
Output Voltage Swing
VDD -
VOUT
TA = +25NC 80
mV
-40NC < TA < +125NC 110
VOUT -
VSS
TA = +25NC 50
-40NC < TA < +125NC 75
AC SPECIFICATIONS
Input Voltage-Noise Density eNf = 1kHz 50 nV/√Hz
Input Voltage Noise 0.1Hz < f < 10Hz 500 nVP-P
Input Current-Noise Density iNf = 1kHz 0.1 pA/√Hz
Gain-Bandwidth Product GBW 1 MHz
Slew Rate SR AV = 1V/V, VOUT = 2VP-P 0.7 V/Fs
Capacitive Loading CLNo sustained oscillation, AV = 1V/V 400 pF
Total Harmonic Distortion Plus
Noise THD+N VOUT = 2VP-P, AV = +1V/V, f = 1kHz -100 dB
EMI Rejection Ratio EMIRR VRF_PEAK = 100mV
f = 400MHz 75
dB
f = 900MHz 78
f = 1800MHz 80
f = 2400MHz 90
4Maxim Integrated
MAX44244/MAX44245/MAX44248
36V, Precision, Low-Power, 90µA,
Single/Quad/Dual Op Amps
ELECTRICAL CHARACTERISTICS
(VDD = 30V, VSS = 0V, VIN+ = VIN- = VDD/2, RL = 5kI to VDD/2, TA = -40NC to +125NC, unless otherwise noted. Typical values are
at +25NC.) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
POWER SUPPLY
Quiescent Current Per Amplifier
(MAX44244 Only) IDD
TA = +25NC 100 160 FA
-40NC < TA < +125NC 190
Quiescent Current Per Amplifier
(MAX44245/MAX44248 Only) IDD
TA = +25NC 90 130 FA
-40NC < TA < +125NC 145
DC SPECIFICATIONS
Input Common-Mode Range VCM Guaranteed by CMRR test VSS -
0.05
VDD -
1.5 V
Common-Mode Rejection Ratio
(Note 3) CMRR
TA = +25NC, VCM = VSS - 0.05V to VDD -
1.5V 130 140
dB
-40NC < TA < +125NC, VCM = VSS - 0.05V
to VDD - 1.5V 126
Input Offset Voltage (Note 3) VOS
TA = +25NC 2 7.5 FV
-40NC < TA < +125NC 10
Input Offset Voltage Drift
(Note 3) TC VOS 10 30 nV/°C
Input Bias Current (Note 3) IB
TA = +25NC 150 300 pA
-40NC < TA < +125NC 700
Input Offset Current (Note 3) IOS
TA = +25NC 300 600 pA
-40NC < TA < +125NC 1400
Open-Loop Gain (Note 3) AVOL VSS + 0.5V P VOUT
P VDD - 0.5V
TA = +25NC 146 150 dB
-40NC < TA < +125NC 140
Output Short-Circuit Current To VDD or VSS, noncontinuous 40 mA
Output Voltage Swing
VDD -
VOUT
TA = +25NC 200
mV
-40NC < TA < +125NC 270
VOUT -
VSS
TA = +25NC 140
-40NC < TA < +125NC 220
AC SPECIFICATIONS
Input Voltage-Noise Density eNf = 1kHz 50 nV/√Hz
Input Voltage Noise 0.1Hz < f < 10Hz 500 nVP-P
Input Current-Noise Density iNf = 1kHz 0.1 pA/√Hz
Gain-Bandwidth Product GBW 1 MHz
5Maxim Integrated
MAX44244/MAX44245/MAX44248
36V, Precision, Low-Power, 90µA,
Single/Quad/Dual Op Amps
Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
ELECTRICAL CHARACTERISTICS (continued)
(VDD = 30V, VSS = 0V, VIN+ = VIN- = VDD/2, RL = 5kI to VDD/2, TA = -40NC to +125NC, unless otherwise noted. Typical values are
at +25NC.) (Note 2)
Note 2: All devices are 100% production tested at TA = +25NC. Temperature limits are guaranteed by design.
Note 3: Guaranteed by design.
Note 4: At IN+ and IN-. Defined as 20log (VRF_PEAK/δVOS).
Typical Operating Characteristics
(VDD = 10V, VSS = 0V, VIN+ = VIN- = VDD/2, RL = 5kω to VDD/2. Typical values are at TA = +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Slew Rate SR AV = 1V/V, VOUT = 2VP-P 0.7 V/Fs
Capacitive Loading CLNo sustained oscillation, AV = 1V/V 400 pF
Total Harmonic Distortion Plus
Noise THD+N VOUT = 2VP-P, AV = +1V/V, f = 1kHz -100 dB
EMI Rejection Ratio EMIRR VRF_PEAK =
100mV
f = 400MHz 75
dB
f = 900MHz 78
f = 1800MHz 80
f = 2400MHz 90
INPUT OFFSET VOLTAGE HISTOGRAM
MAX44248 toc01
INPUT OFFSET VOLTAGE (µV)
OCCURANCE (%)
3.02.51.51.0 2.00.50
5
10
15
20
25
30
35
40
45
0
3.5
INPUT OFFSET VOLTAGE DRIFT
MAX44248 toc02
INPUT OFFSET VOLTAGE DRIFT (nV/°C)
OCCURANCE (%)
141312111098765
5
10
15
20
25
30
35
0
4
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX44248 toc03
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (µA)
302010
82
84
86
88
90
92
94
96
98
100
80
04
0
6Maxim Integrated
MAX44244/MAX44245/MAX44248
36V, Precision, Low-Power, 90µA,
Single/Quad/Dual Op Amps
Typical Operating Characteristics (continued)
(VDD = 10V, VSS = 0V, VIN+ = VIN- = VDD/2, RL = 5kω to VDD/2. Typical values are at TA = +25°C.)
SUPPLY CURRENT
vs. TEMPERATURE
MAX44248 toc04
TEMPERATURE (°C)
SUPPLY CURRENT (µA)
1007525 500-25
82
84
86
88
90
92
94
96
98
100
80
-50 125
INPUT OFFSET VOLTAGE
vs. COMMON-MODE VOLTAGE
MAX44248 toc05
COMMON-MODE VOLTAGE (V)
OFFSET VOLTAGE (µV)
240-2-4
-3
-2
-1
0
1
2
-4
-6 6
INPUT OFFSET VOLTAGE
VS. TEMPERATURE
MAX44248 toc06
TEMPERATURE (°C)
OFFSET VOLTAGE (µV)
10075-25 0 25 50
-4
-3
-2
-1
0
1
2
3
-5
-50 125
INPUT BIAS CURRENT
VS. COMMON-MODE VOLTAGE
MAX44248 toc07
COMMON-MODE VOLTAGE (V)
INPUT BIAS CURRENT (pA)
8642
20
40
60
80
100
120
140
160
180
0
01
0
COMMON-MODE REJECTION RATIO
vs. FREQUENCY
MAX44248 toc09
FREQUENCY (Hz)
CMRR (dB)
100k10k1k100
-120
-100
-80
-60
-40
-20
0
-140
10 1M
INPUT BIAS CURRENT
vs. TEMPERATURE
MAX44248 toc08
TEMPERATURE (°C)
INPUT BIAS CURRENT (pA)
1007550250-25
-200
0
200
400
600
800
-400
-50 125
COMMON-MODE REJECTION RATIO
vs. TEMPERATURE
MAX44248 toc10
TEMPERATURE (°C)
CMRR (dB)
1007550250-25
-130
-125
-120
-115
-110
-105
-100
-135
-50 125
7Maxim Integrated
MAX44244/MAX44245/MAX44248
36V, Precision, Low-Power, 90µA,
Single/Quad/Dual Op Amps
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
MAX44248 toc11
FREQUENCY (Hz)
PSRR (dB)
100k10k100 1k
-140
-120
-100
-80
-60
-40
-20
0
-160
10 1M
OUTPUT VOLTAGE HIGH
vs. TEMPERATURE
MAX44248 toc12
TEMPERATURE (°C)
VDD - VOUT (mV)
1007525 500-25
10
20
30
40
50
60
70
80
0
-50 125
OUTPUT VOLTAGE LOW
vs. TEMPERATURE
MAX44248 toc13
TEMPERATURE (°C)
VOUT - VSS (mV)
1007550250-25
10
20
30
40
50
60
0
-50 125
OUTPUT VOLTAGE HIGH
vs. SOURCE CURRENT
MAX44248 toc14
SOURCE CURRENT (mA)
VDD - VOUT (mV)
1
10
100
1000
1
0.1 10
INPUT VOLTAGE NOISE
vs. FREQUENCY
MAX44248 toc16
FREQUENCY (Hz)
INPUT VOLTAGE NOISE (nV/√Hz)
10k1k100
20
40
60
80
100
120
140
160
180
200
0
10 100k
OUTPUT VOLTAGE LOW
vs. SINK CURRENT
MAX44248 toc15
SINK CURRENT (mA)
VOUT - VSS (mV)
1
10
100
1000
1
0.1 10
INPUT VOLTAGE 0.1Hz TO 10Hz NOISE
MAX44248 toc17
400nV/div
1s/div
Typical Operating Characteristics (continued)
(VDD = 10V, VSS = 0V, VIN+ = VIN- = VDD/2, RL = 5kω to VDD/2. Typical values are at TA = +25°C.)
8Maxim Integrated
MAX44244/MAX44245/MAX44248
36V, Precision, Low-Power, 90µA,
Single/Quad/Dual Op Amps
Typical Operating Characteristics (continued)
(VDD = 10V, VSS = 0V, VIN+ = VIN- = VDD/2, RL = 5kω to VDD/2. Typical values are at TA = +25°C.)
INPUT CURRENT NOISE
vs. FREQUENCY
MAX44248 toc18
FREQUENCY (Hz)
INPUT-CURRENT NOISE (pA/√Hz)
10k1k100
1
2
3
4
5
6
7
8
9
10
0
10 100k
LARGE-SIGNAL GAIN vs. FREQUENCY
MAX44248 toc20
FREQUENCY (Hz)
LARGE-SIGNAL GAIN (dB)
100k10k100 1k101
-20
0
20
40
60
80
100
120
140
-40
0.1 1M
SMALL-SIGNAL GAIN vs. FREQUENCY
MAX44248 toc19
FREQUENCY (Hz)
SMALL-SIGNAL GAIN (dB)
100k10k100 1k101
-20
0
20
40
60
80
100
120
140
-40
0.1 1M
POWER-UP TIME
MAX44248 toc23
VOUT
2V/div
VDD
10V/div
20µs/div
TOTAL HARMONIC DISTORTION
vs. FREQUENCY
MAX44248 toc24
FREQUENCY (Hz)
THD (dB)
10k1k100
-120
-100
-80
-60
-40
-20
0
-140
10 100k
RLOAD = 600I
RLOAD = 1kI
RLOAD = 5kI
LARGE-SIGNAL STEP RESPONSE
MAX44248 toc22
VOUT
500mV/div
VIN
2V/div
4µs/div
SMALL-SIGNAL STEP RESPONSE
MAX44248 toc21
VOUT
50mV/div
VIN
100mV/div
4µs/div
9Maxim Integrated
MAX44244/MAX44245/MAX44248
36V, Precision, Low-Power, 90µA,
Single/Quad/Dual Op Amps
Typical Operating Characteristics (continued)
(VDD = 10V, VSS = 0V, VIN+ = VIN- = VDD/2, RL = 5kω to VDD/2. Typical values are at TA = +25°C.)
OUTPUT STABILITY
vs. CAPACITIVE LOAD
MAX44248 toc25
CAPACITIVE LOAD (pF)
RESISTIVE LOAD (I)
10,0001000
10
100
1k
10k
1
100 100,000
UNSTABLE
STABLE
OUTPUT STABILITY
vs. ISOLATION RESISTANCE
MAX44248 toc26
CAPACITIVE LOAD (pF)
ISOLATION RESISTANCE (I)
10,0001000
10
100
1k
10k
1
100 100,000
UNSTABLE
STABLE
CROSSTALK vs. FREQUENCY
MAX44248 toc27
FREQUENCY (Hz)
CROSSTALK (dB)
100k10k1k
-120
-100
-80
-60
-40
-20
0
-140
100 1M
OUTPUT IMPEDANCE
vs. FREQUENCY
MAX44248 toc28
FREQUENCY (Hz)
OUTPUT IMPEDANCE (I)
100k10k1k
10
20
30
40
50
60
70
80
90
100
0
100 1M
EMIRR vs. FREQUENCY
MAX44248 toc29
FREQUENCY (MHz)
EMIRR (dB)
1,000100
20
40
60
80
100
120
0
10 10,000
10Maxim Integrated
MAX44244/MAX44245/MAX44248
36V, Precision, Low-Power, 90µA,
Single/Quad/Dual Op Amps
Pin Configurations
OUTA +
INA-
INA+
1
2
3
4
8
7
6
5VSS
VDD
OUTB
INB-
INB+
SO-8
MAX44248
1
2
3
4
8
7
6
5
VDD
OUTB
INB-
INB+VSS
INA+
INA-
OUTA
µMAX
+
MAX44248
MAX44244
SOT23
TOP VIEW
VSS
INA+
1OUTA
2
3 INA-
5V
DD
4
+
1
2
3
4
8
7
6
5
N.C.
VDD
OUTA
N.C.VSS
INA+
INA-
N.C.
µMAX
+
MAX44244
14
13
12
11
10
9
8
1
2
3
4
5
6
7
OUTD
IND-
IND+
VSS
VDD
INA+
INA-
OUTA
MAX44245
INC+
INC-
OUTCOUTB
INB-
INB+
TSSOP
+
IND+
VSS
VDD
1
2
14
13
OUTD
IND-INA-
INA+
OUTA
3
4
12
11
INC-
OUTCOUTB
510 INC+INB+
INB- 6
7
9
8
+
SO-14
MAX44245
11Maxim Integrated
MAX44244/MAX44245/MAX44248
36V, Precision, Low-Power, 90µA,
Single/Quad/Dual Op Amps
Pin Description
Detailed Description
The MAX44244/MAX44245/MAX44248 are high-precision
amplifiers with less than 2FV (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.
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.
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.
Applications Information
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.
The Typical Operating Circuit shows how the device can
be used to make a current loop driver.
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
PIN
NAME FUNCTION
MAX44244 MAX44245 MAX44248
SOT23 µMAX SO-14 TSSOP SO-8 µMAX
1 6 1 1 1 1 OUTA Channel A Output
2 4 11 11 4 4 VSS Negative Supply Voltage
3 3 3 3 3 3 INA+ Channel A Positive Input
4 2 2 2 2 2 INA- Channel A Negative Input
5 7 4 4 8 8 VDD Positive Supply Voltage
— — 5 5 5 5 INB+ Channel B Positive Input
— — 6 6 6 6 INB- Channel B Negative Input
— — 7 7 7 7 OUTB Channel B Output
— — 8 8 — — OUTC Channel C Output
— — 9 9 — — INC- Channel C Negative Input
— — 10 10 — — INC+ Channel C Positive Input
— — 12 12 — — IND+ Channel D Positive Input
— — 13 13 — — IND- Channel D Negative Input
— — 14 14 — — OUTD Channel D Output
— 1, 5, 8 — — — — N.C. No Connection. Not internally
connected.
12Maxim Integrated
MAX44244/MAX44245/MAX44248
36V, Precision, Low-Power, 90µA,
Single/Quad/Dual Op Amps
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
RSENSE. Therefore, if RSENSE = 50Ω (i.e. 20mA will drop
1V) and if the current through R3 is 10µA when IOUT is
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-
range. RSENSE is ratiometric with R3, R1 independently
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 (< 300FA, 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 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.
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.
Figure 1. Weight Application
5V
5V
5V
VDD
VSS
MICRO-
CONTROLLER
RF
RF
RG
VDD
VSS
VIN-
VIN+ SCKSCLK
RDY/DOUT MISO
AMP A
AMP B
MAX11205
½ MAX44248
½ MAX44248 5V
13Maxim Integrated
MAX44244/MAX44245/MAX44248
36V, Precision, Low-Power, 90µA,
Single/Quad/Dual Op Amps
Chip Information
PROCESS: BiCMOS
Package Information
For the latest package outline information and land patterns (foot-
prints), 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.
Ordering Information
+Denotes a lead(Pb)-free/RoHS-compliant package.
PART TEMP RANGE PIN-
PACKAGE
TOP
MARK
MAX44244AUK+ -40°C to +125°C 5 SOT23 AFMR
MAX44244AUA+ -40°C to +125°C 8 µMAX —
MAX44245ASD+ -40°C to +125°C 14 SO —
MAX44245AUD+ -40°C to +125°C 14 TSSOP —
MAX44248AUA+ -40°C to +125°C 8 µMAX —
MAX44248ASA+ -40°C to +125°C 8 SO —
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
5 SOT23 U5+1 21-0057 90-0174
8 SO S8+4 21-0041 90-0096
8 µMAX U8+1 21-0036 90-0092
14 SO S14M+4 21-0041 90-0112
14 TSSOP U14M+1 21-0066 90-0113
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 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000 14
© 2015 Maxim Integrated The Maxim logo and Maxim Integrated are trademarks of Maxim Integrated Products, Inc.
MAX44244/MAX44245/MAX44248
36V, Precision, Low-Power, 90µA,
Single/Quad/Dual Op Amps
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 7/12 Initial release —
1 6/13
Added the MAX44244/MAX44245 to data sheet. Updated the Electrical
Characteristics, Absolute Maximum Ratings, Pin Description, and Pin
Configurations.
1–13
2 9/13 Released the MAX44244 for introduction. Revised the Electrical
Characteristics 2–5, 13
3 6/14 Corrected Figure 1 and Package Information 12, 13
4 12/14 Updated Benefits and Features section 1
5 9/15 Updated Typical Operating Circuit 1
15Maxim Integrated
MAX44244/MAX44245/MAX44248
36V, Precision, Low-Power, 90µA,
Single/Quad/Dual Op Amps
