MAX44241/MAX44243/MAX44246
36V, Low-Noise, Precision,
Single/Quad/Dual Op Amps
19-6375; Rev 7; 4/15
Ordering Information appears at end of data sheet.
For related parts and recommended products to use with this part,
refer to www.maximintegrated.com/MAX44241.related.
Typical Operating Circuit
µMAX is a registered trademark of Maxim Integrated Products, Inc.
EVALUATION KIT AVAILABLE
General Description
The MAX44241/MAX44243/MAX44246 are 36V, ultra-
precision, low-noise, low-drift, single/quad/dual opera-
tional amplifiers that offer near-zero DC offset and drift
through the use of patented chopper stabilized and
auto-zeroing techniques. This method constantly mea-
sures and compensates the input offset, eliminating drift
over time and temperature and the effect of 1/f noise.
These single/quad/dual devices feature rail-to-rail out-
puts, operate from a single 2.7V to 36V supply or dual
±1.35V to ±18V supplies, and consume only 0.42mA per
channel, with only 9nV/√Hz input-referred voltage noise.
The ICs are available in 8-pin FMAXM or SO packages
and are rated over the -40NC to +125NC temperature
range.
Applications
Benefits and Features
S Reduces Noise-Sensitive Precision Applications
• Low 9nV/√Hz Noise at 1kHz
• Integrated EMI Filter
S Eliminates Cost of Calibration with Increased
Accuracy and Patented Auto-Zero Circuitry
• Ultra-Low Input VOS: 5µV (max)
• Low 20nV/°C (max) of Offset Drift
S Suitable for High-Bandwidth Applications
• 1µs Fast Settling Time
• 5MHz Gain-Bandwidth Product
S Low 0.55mA Per Channel (max) Quiescent Current
S Wide Supply for High-Voltage Front-Ends
• 2.7V to 36V Supply Range
S Rail-to-Rail Output
Battery-Powered
Equipment
PLC Analog I/O
Modules
Transducer Amplifiers
Load Cell Amplifiers
Precision
Instrumentation
15V
15V
15V
3.3V
3V
VDD
MICRO-
PROCESSOR
VOUT
50RG
50RG
RG
VREF
VDD
VSS
VIN-
VIN+
C1
BUFFER
BUFFER
½ MAX44246
½ MAX44246
MAX11211
MAX6126
R
R
15V
1.5V
BUFFER
R
R
R1
OUTPUT
½ MAX44246
-15V
-15V
-15V
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
MAX44241/MAX44243/MAX44246
36V, Low-Noise, Precision,
Single/Quad/Dual Op Amps
Supply Voltage (VDD to GND) .............................-0.3V to +40V
All Other Pins ................................(GND - 0.3V) to (VDD + 0.3V)
Short-Circuit Duration, OUTA,
OUTB to Either Supply Rail………………………… ............. 1s
Continuous Input Current (Any Pin) ..................................20mA
Differential Input Current ................................................. Q20mA
Differential Input Voltage (Note 1) ....................................... .Q6V
Continuous Power Dissipation (TA = +70NC)
5-Pin SOT23 (derate 3.9mW/NC above +70NC).......312.6mW
8-Pin FMAX (derate 4.8mW/NC above +70NC) ........387.8mW
8-Pin SO (derate 7.60mW/NC above +70NC)...........606.1mW
14-Pin SO (derate 12.30mW/NC above +70NC).......987.7mW
14-Pin TSSOP (derate 10mW/NC above +70NC) .....796.8mW
Operating Temperature Range ........................ -40NC to +125NC
Junction Temperature ....................................................+150NC
Storage Temperature Range ............................ -65NC to +150NC
Lead Temperature (soldering,10s) .................................+300NC
Soldering Temperature (reflow) ......................................+260NC
ABSOLUTE MAXIMUM RATINGS
Note 2: 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.
Note 1: The amplifier inputs are connected by internal back-to-back clamp diodes. In order to minimize noise in the input stage,
current-limiting resistors are not used. If differential input voltages exceeding ±1V are applied, limit input current to 20mA.
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.
µMAX
Junction-to-Ambient Thermal Resistance (qJA) .....206.3NC/W
Junction-to-Case Thermal Resistance (qJC) ..............42NC/W
SO-8
Junction-to-Ambient Thermal Resistance (qJA) ........132NC/W
Junction-to-Case Thermal Resistance (qJC) ..............38NC/W
SO-14
Junction-to-Ambient Thermal Resistance (qJA) ..........81NC/W
Junction-to-Case Thermal Resistance (qJC) ..............32NC/W
SOT23
Junction-to-Ambient Thermal Resistance (qJA) .....255.9NC/W
Junction-to-Case Thermal Resistance (qJC) ..............81NC/W
TSSOP
Junction-to-Ambient Thermal Resistance (qJA) .....100.4NC/W
Junction-to-Case Thermal Resistance (qJC) ..............30NC/W
PACKAGE THERMAL CHARACTERISTICS (Note 2)
ELECTRICAL CHARACTERISTICS
(VDD = 30V, VGND = 0V, VIN+ = VIN- = VDD/2, RL = 5kΩ to VDD /2, TA = -40°C to +125°C, unless otherwise noted. Typical values at
TA = +25°C.) (Note 3)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Supply Voltage Range
V
DD Guaranteed by PSRR 2.7 36
V
Power-Supply Rejection Ratio
(Note 4) PSRR VDD = 2.7V to 36V, TA =
+25NC
148 166
dB
VDD = 2.7V to 36V, -40NC < TA < +125NC 146
Quiescent Current per
Amplifier
IDD RL = JTA =
+25NC
0.42 0.55 mA
-40NC < TA <
+125N
C0.60
Power-Up Time tON 20 Fs
DC SPECIFICATIONS
Input Common-Mode Range VCM Guaranteed by
CMRR
test (VGND
- 0.05)
(VDD
- 1.5)
V
Common-Mode Rejection Ratio
(Note 4) CMRR VCM = (VGND - 0.05V) to (VDD - 1.5V) 146 166
dB
Input Offset Voltage (Note 4)
V
OS
1 5 F
V
3Maxim Integrated
MAX44241/MAX44243/MAX44246
36V, Low-Noise, Precision,
Single/Quad/Dual Op Amps
ELECTRICAL CHARACTERISTICS (continued)
(VDD = 30V, VGND = 0V, VIN+ = VIN- = VDD/2, RL = 5kΩ to VDD /2, TA = -40°C to +125°C, unless otherwise noted. Typical values at
TA = +25°C.) (Note 3)
ELECTRICAL CHARACTERISTICS
(VDD = 10V, VGND = 0V, VIN+ = VIN- = VDD/2, RL = 5kΩ to VDD /2, TA = -40°C to +125°C, unless otherwise noted. Typical values at
TA = +25°C.) (Note 3)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Input Offset Voltage Drift
(Note 4) TC VOS 1 20
nV/NC
Input Bias Current (Note 4) IB
TA =
+25NC
300 600
pA
-40NC < TA <
+125N
C1250
Input Offset Current (Note 4) I
OS
TA =
+25NC
600 1200
pA
-40NC < TA <
+125N
C2500
Open-Loop Gain (Note 4) AVOL (VGND + 0.5V) P VOUT P (VDD – 0.5V) 154 168
dB
Output Short-Circuit Current Noncontinuous Sinking 40 mA
Sourcing 30
Output Voltage Low
V
OL TA =
+25NC
90 115
mV
-40NC < TA <
+125N
C180
Output Voltage
High
V
OH
TA =
+25NC
(VDD -
0.17)
(VDD -
0.13)
V
-40NC < TA <
+125N
C(VDD -
0.25)
AC SPECIFICATIONS
Input Voltage-Noise Density eNf = 1kHz 9
nV/
√
Hz
Input Voltage Noise 0.1Hz < f < 10Hz 117 nVP-P
Input
Capacitance
CIN 2 pF
Gain-Bandwidth
Product
GBW 5 MHz
Phase
Margin
PM
CL = 20pF 60
Degrees
Slew Rate
SR
AV = 1V/V, VOUT = 4VP-P 3.8 V/Fs
Capacitive
Loading
CLNo sustained oscillation, AV = 1V/V 300 pF
Total Harmonic Distortion THD
VOUT = 4VP-P,
AV = +1V/V
f = 1kHz -96
dB
f = 20kHz -77
VOUT = 2VP-P,
AV = +1V/V
f = 1kHz -91
dB
f = 20kHz -76
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
POWER SUPPLY
Quiescent Current per
Amplifier
IDD RL = JTA =
+25NC
0.42 0.55 mA
-40NC < TA <
+125N
C0.60
Power-Up Time tON 20 Fs
4Maxim Integrated
MAX44241/MAX44243/MAX44246
36V, Low-Noise, Precision,
Single/Quad/Dual Op Amps
ELECTRICAL CHARACTERISTICS (continued)
(VDD = 10V, VGND = 0V, VIN+ = VIN- = VDD/2, RL = 5kΩ to VDD /2, TA = -40°C to +125°C, unless otherwise noted. Typical values at
TA = +25°C.) (Note 3)
Note 3: All devices are 100% production tested at TA = +25°C. Temperature limits are guaranteed by design.
Note 4: Guaranteed by design.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
DC SPECIFICATIONS
Input Common-Mode Range VCM Guaranteed by
CMRR
test (VGND
- 0.05)
(VDD –
1.5)
V
Common-Mode Rejection Ratio
(Note 4) CMRR VCM = (VGND - 0.05V) to (VDD - 1.5V) 140 158
dB
Input Offset Voltage (Note 4)
V
OS
1 5 FV
Input Offset Voltage Drift (Note 4) TC VOS 2.4 20
nV/NC
Input Bias Current (Note 4) IB
TA =
+25NC
300 600
pA
-40NC < TA <
+125N
C1100
Input Offset Current (Note 4) I
OS
TA =
+25NC
600 1200
pA
-40NC < TA <
+125N
C2200
Open-Loop Gain (Note 4) AVOL (VGND + 0.5V) ≤ VOUT ≤ (VDD - 0.5V) 144 164
dB
Output Short-Circuit Current Noncontinuous Sinking 40 mA
Sourcing 30
Output Voltage Low
V
OL TA =
+25NC
30 40
mV
-40NC < TA <
+125N
C60
Output Voltage
High
VOH
TA =
+25NC
(VDD -
0.06)
(VDD -
0.05)
V
-40NC < TA <
+125N
C(VDD -
0.09)
AC SPECIFICATIONS
Input Voltage-Noise Density eNf = 1kHz 9
nV/
√
Hz
Input Voltage Noise 0.1Hz < f < 10Hz 117 nVP-P
Input
Capacitance
CIN 2pF
Gain-Bandwidth
Product
GBW 5MHz
Phase Margin PM CL = 20pF 60 Degrees
Slew Rate SR AV = +1V/V, VOUT = 2VP-P, 10% to 90% 3.8 V/µs
Capacitive Loading CLNo sustained oscillation, AV = 1V/V 300 pF
Total Harmonic Distortion THD VOUT = 2VP-P,
AV = 1V/V
f = 1kHz -92 dB
f = 20kHz -76
Settling Time To 0.01%, VOUT = 2V step, AV = 1V/V 1µs
5Maxim Integrated
MAX44241/MAX44243/MAX44246
36V, Low-Noise, Precision,
Single/Quad/Dual Op Amps
Typical Operating Characteristics
(VDD = 10V, VGND = 0V, VIN+ = VIN- = VDD/2, RL = 5kΩ to VDD/2, TA = -40°C to +125°C, unless otherwise noted. Typical values are
at TA = +25°C.) (Note 3)
INPUT OFFSET VOLTAGE HISTOGRAM
MAX44241 toc01
OFFSET VOLTAGE (µV)
PERCENT OCCURENCE (%)
1.00 0.5-0.5-1.0
5
10
15
20
25
30
35
0
-1.5 1.5
INPUT OFFSET VOLTAGE DRIFT
HISTOGRAM
MAX44241 toc02
OFFSET VOLTAGE DRIFT (µV/°C)
PERCENT OCCURRENCE (%)
0.0030 0.002-0.004 -0.002-0.006
5
10
15
20
25
30
35
40
45
0
0.005
SUPPLY CURRENT PER AMPLIFIER
vs. SUPPLY VOLTAGE
MAX44241 toc03
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (µA)
353020 2510 155
04
0
50
100
150
200
250
300
350
400
450
500
VIN = VDD/2
NO LOAD
SUPPLY CURRENT PER AMPLIFIER
vs. TEMPERATURE
MAX44241 toc04
TEMPERATURE (°C)
SUPPLY CURRENT (µA)
1007550250-25-50 125
400
410
420
430
440
450
460
470
390
VIN = VDD/2
NO LOAD
INPUT BIAS CURRENT vs. VCM
vs. TEMPERATURE
MAX44241 toc07
VCM (V)
INPUT BIAS CURRENT (pA)
875 61 2 3 40
-800
-600
-400
-200
0
200
400
600
800
1000
1200
1400
1600
1800
2000
-1000
-1 9
IB- (
TA =
-40°C)
IB+ (
TA =
+125°C)
IB- (
TA =
+125°C)
IB+ (
TA =
-40°C)
IB- (
TA =
+25°C)
IB+ (
TA =
+25°C)
INPUT OFFSET VOLTAGE vs. INPUT
COMMON-MODE VOLTAGE
MAX44241 toc05
VCM (V)
INPUT OFFSET VOLTAGE (µV)
87654321
-2
-1
0
1
2
3
-3
09
-300
-200
-100
0
100
200
300
400
500
600
700
-50 050 100 150
INPUT BIAS CURRENT (pA)
TEMPERATURE (°C)
INPUT BIAS CURRENT
vs. TEMPERATURE
toc08
IB-
IB+
INPUT OFFSET VOLTAGE
vs. TEMPERATURE
MAX44241 toc06
INPUT OFFSET VOLTAGE (µV)
5
-5
TEMPERATURE (°C)
1007550250-25-50 125
0
90
100
110
120
140
150
160
170
130
COMMON-MODE REJECTION RATIO
vs. TEMPERATURE
MAX44241 toc09
CMRR (dB)
180
80
TEMPERATURE (°C)
1007550250-25-50 125
6Maxim Integrated
MAX44241/MAX44243/MAX44246
36V, Low-Noise, Precision,
Single/Quad/Dual Op Amps
Typical Operating Characteristics (continued)
(VDD = 10V, VGND = 0V, VIN+ = VIN- = VDD/2, RL = 5kΩ to VDD/2, TA = -40°C to +125°C, unless otherwise noted. Typical values are
at TA = +25°C.) (Note 3)
COMMON-MODE REJECTION RATIO
vs. FREQUENCY
MAX44241 toc10
FREQUENCY (Hz)
MAGNITUDE (dB)
1M100k1k 10k10 1001
0
-20
20
40
60
80
100
120
140
160
-40
0.1 10M
100mVP-P
90
100
110
120
140
150
160
170
130
POWER-SUPPLY REJECTION RATIO
vs. TEMPERATURE
MAX44241 toc11
PSRR (dB)
180
80
TEMPERATURE (°C)
1007550250-25-50 125
OPEN-LOOP GAIN vs. FREQUENCY
MAX44241 toc12
FREQUENCY (Hz)
MAGNITUDE (dB)
1M100k1k 10k10 10010.01 0.1 10M100M
200
-50
0
50
100
150
VIN = 100mVP-P
OUTPUT VOLTAGE LOW
vs. TEMPERATURE
MAX44241 toc15
VOL (mV)
70
0
TEMPERATURE (°C)
1007550250-25-50 125
10
20
30
40
50
60
OUTPUT VOLTAGE LOW
vs. OUTPUT SINK CURRENT
MAX44241 toc13
OUTPUT SINK CURRENT (mA)
OUTPUT VOLTAGE LOW (mV)
8642
01
0
50
100
150
200
300
350
400
450
250
500
0
OUTPUT VOLTAGE HIGH
vs. TEMPERATURE
MAX44241 toc16
OUTPUT VOLTAGE HIGH (V)
9.970
9.930
TEMPERATURE (°C)
1007550250-25-50 125
9.940
9.935
9.945
9.955
9.950
9.965
9.960
OUTPUT VOLTAGE HIGH
vs. OUTPUT SOURCE CURRENT
MAX44241 toc14
OUTPUT SOURCE CURRENT (mA)
OUTPUT VOLTAGE HIGH (mV)
8642
50
100
150
200
250
300
350
400
450
0
0 10
SMALL-SIGNAL GAIN vs. FREQUENCY
MAX44241 toc17
FREQUENCY (Hz)
MAGNITUDE (dB)
1M100k1k 10k100
2
-20
10 100M10M
-18
-16
-14
-12
-10
-8
-6
-4
-2
0
NORMALIZED GAIN,
VIN = 100mVP-P
LARGE-SIGNAL GAIN vs. FREQUENCY
MAX44241 toc18
FREQUENCY (Hz)
MAGNITUDE (dB)
10M1M10k 100k1k100
-45
-40
-35
-30
-25
-20
-15
-10
-5
0
5
-50
10 100M
NORMALIZED GAIN,
VIN = 2VP-P
7Maxim Integrated
MAX44241/MAX44243/MAX44246
36V, Low-Noise, Precision,
Single/Quad/Dual Op Amps
Typical Operating Characteristics (continued)
(VDD = 10V, VGND = 0V, VIN+ = VIN- = VDD/2, RL = 5kΩ to VDD/2, TA = -40°C to +125°C, unless otherwise noted. Typical values are
at TA = +25°C.) (Note 3)
INPUT VOLTAGE 0.1Hz TO 10Hz NOISE
MAX44241 toc20
1s/div
200nV/div
SMALL-SIGNAL (100mVP-P)
STEP RESPONSE vs. TIME
MAX44241 toc21
1µs/div
VIN
50mV/div
VOUT
50mV/div
0.01
0.1
1
10
STABILITY vs. CAPACITIVE AND
RESISTIVE LOAD IN PARALLEL
MAX44246 toc24
CAPACITIVE LOAD (pF)
RESISTIVE LOAD (kI)
1k 10k
100
0.001
100 100k
UNSTABLE
STABLE
POWER-UP TIME
MAX44241 toc25
20µs
VIN = VOUT = 0V
VDD = VSS = 0V VDD = 10V
200mV/div
5V/div
LARGE-SIGNAL (2VP-P)
STEP RESPONSE vs. TIME
MAX44241 toc22
1µs/div
VIN
1V/div
VOUT
1V/div
STABILITY vs. CAPACITIVE LOAD AND
SERIES ISOLATION RESISTANCE
MAX44241 toc23
CAPACITIVE LOAD (pF)
RISO (I)
1k 10k
1
10
100
0.1
100 100k
UNSTABLE
STABLE
INPUT VOLTAGE NOISE vs. FREQUENCY
MAX44241 toc19
FREQUENCY (Hz)
INPUT VOLTAGE NOISE (nV/√Hz)
10k1k10010
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
0
1 100k
8Maxim Integrated
MAX44241/MAX44243/MAX44246
36V, Low-Noise, Precision,
Single/Quad/Dual Op Amps
Typical Operating Characteristics (continued)
(VDD = 10V, VGND = 0V, VIN+ = VIN- = VDD/2, RL = 5kΩ to VDD/2, TA = -40°C to +125°C, unless otherwise noted. Typical values are
at TA = +25°C.) (Note 3)
TOTAL HARMONIC DISTORTION
vs. FREQUENCY
MAX44241 toc26
FREQUENCY (Hz)
THD (dB)
10k1k100
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
-120
10 100k
2VP-P OUTPUT
4VP-P OUTPUT
TOTAL HARMONIC DISTORTION
vs. OUTPUT AMPLITUDE
MAX44241 toc27
OUTPUT AMPLITUDE (V)
THD (dB)
987654321
-100
-80
-60
-40
-20
0
-120
010
CROSSTALK vs. FREQUENCY
MAX44241 toc28
FREQUENCY (Hz)
CROSSTALK (dB)
10k1k 1M10 100
-120
-100
-80
-60
-40
-20
0
-160
-140
1 10M100k
TOTAL HARMONIC DISTORTION
vs. FREQUENCY
MAX44241 toc29
FREQUENCY (Hz)
THD (dB)
10k1k100
-110
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
-120
10 100k
2VP-P INPUT
VDD = 30V
4VP-P INPUT
EMIRR
vs. FREQUENCY (VDD = 3.3V)
MAX44246 toc30
FREQUENCY (MHz)
EMIRR (dB)
1000100101 10,000
10
20
30
40
50
60
70
80
90
100
0
9Maxim Integrated
MAX44241/MAX44243/MAX44246
36V, Low-Noise, Precision,
Single/Quad/Dual Op Amps
Pin Configurations
INB-
INB+GND
1
2
8
7
VDD
OUTBINA-
INA+
OUTA
3
4
6
5
MAX44246
µMAX/SO
+
IND+
VSS
VDD
1
2
14
13
OUTD
IND-INA-
INA+
OUTA
3
4
12
11
INC-
OUTCOUTB
5 10 INC+INB+
INB- 6
7
9
8
+
SO
MAX44243
MAX44241
SOT-23
TOP VIEW
VSS
INA+
1OUTA
2
3 INA-
5 VDD
4
+
14
13
12
11
10
9
8
1
2
3
4
5
6
7
OUTD
IND-
IND+
VSS
VDD
INA+
INA-
OUTA
MAX44243
INC+
INC-
OUTCOUTB
INB-
INB+
TSSOP
+
1
2
3
4
8
7
6
5
N.C.
VDD
OUTA
N.C.VSS
INA+
INA-
N.C.
µMAX
+
MAX44241
10Maxim Integrated
MAX44241/MAX44243/MAX44246
36V, Low-Noise, Precision,
Single/Quad/Dual Op Amps
Pin Descriptions
PIN
NAME FUNCTION
MAX44241 MAX44243 MAX44246
SOT23-5 µMAX-8 SO-14 TSSOP-14 SO-8 µMAX-8
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.
11Maxim Integrated
MAX44241/MAX44243/MAX44246
36V, Low-Noise, Precision,
Single/Quad/Dual Op Amps
Detailed Description
The MAX44241/MAX44243/MAX44246 are high-precision
amplifiers that provide below 5µV of maximum input-
referred offset and low flicker noise. These characteris-
tics are achieved by using a combination of proprietary
auto-zeroing and chopper stabilized techniques. This
combination of auto-zeroing and chopping ensures that
these amplifiers give all the benefits of zero-drift ampli-
fiers, while still ensuring low noise, minimizing chopper
spikes, and providing wide bandwidth. Offset voltages
due to power ripple/spikes as well as common-mode
variation, are corrected resulting in excellent PSRR and
CMRR specifications.
Noise Suppression
Flicker noise, inherent in all active devices, is inverse-
ly proportional to frequency present. Charges at the
oxide-silicon interface that are trapped-and-released
by MOSFET oxide occurs at low frequency more often.
For this reason, flicker noise is also called 1/f noise. The
MAX44241/MAX44243/MAX44246 eliminate the 1/f noise
internally, thus making them ideal choices for DC or sub-
Hz precision applications. The 1/f noise appears as a
slow varying offset voltage and is eliminated by the chop-
ping technique used.
Electromagnetic interference (EMI) noise occurs at higher
frequency, resulting in malfunction or degradation of elec-
trical equipment. The ICs have an input EMI filter to avoid
the output being affected by radio frequency interference.
The EMI filter composed of passive devices, presents sig-
nificant higher impedance to higher frequency.
Applications Information
ADC Buffer Amplifier
The MAX44241/MAX44243/MAX44246 have low input
offset voltage, low noise, and fast settling time that make
these amplifiers ideal for ADC buffers. Weight scales
are one application that often requires a low-noise, high-
voltage amplifier in front of an ADC. The Typical Operating
Circuit details an example of a load cell and ampli-
fier driven from the same ±10V supplies, along with the
MAX11211 18-bit delta sigma ADC. Load cells produce a
very small voltage change at their outputs; therefore driv-
ing the excitation source with a higher voltage produces
a wider dynamic range that can be measured at the ADC
inputs.
The MAX11211 ADC operates from a single 2.7V to 3.6V
analog supply, offers 18-bit noise-free resolution and
0.86mW power dissipation. The MAX11211 also offers
> 100dB rejection at 50Hz and 60Hz. This ADC is part of
a family of 16-, 18-, 20-, and 24-bit delta sigma ADCs with
high precision and < 1mW power dissipation.
The low input offset voltage and low noise of MAX44241/
MAX44243/MAX44246 allow a gain circuit to precede the
MAX11211 without losing any dynamic range at the ADC.
See the Typical Operating Circuit.
Precision Low-Side Current Sensing
The ICs’ ultra-low offset voltage and drift make them
ideal for precision current-sensing applications. Figure 1
shows the ICs in a low-side current-sense configuration.
This circuit produces an accurate output voltage, VOUT
equal to ILOAD x RSENSE x (1 + R2/R1).
Figure 1. Low-Side Current Sensing
VSUPPLY
OUT
R2
R1
ILOAD
RSENSE
½ MAX44246
12Maxim Integrated
MAX44241/MAX44243/MAX44246
36V, Low-Noise, Precision,
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.
Layout Guidelines
The MAX44241/MAX44243/MAX44246 feature ultra-low
offset voltage and noise. Therefore, to get optimum per-
formance follow the following layout guidelines.
Avoid temperature gradients at the junction of two dis-
similar 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 thermo-
couple. 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 junctions remain the same. For
example, consider using dummy 0Ω resistors oriented
in such a way that the thermoelectric sources, 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.
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
Ordering Information
+Denotes a lead(Pb)-free/RoHS-compliant package.
PART TEMP RANGE PIN-
PACKAGE
TOP
MARK
MAX44241AUA+ -40NC to +125NC 8 FMAX —
MAX44241AUK+ -40NC to +125NC5 SOT23 AFMQ
MAX44243ASD+ -40NC to +125NC14 SO —
MAX44243AUD+ -40NC to +125NC14 TSSOP —
MAX44246ASA+ -40NC to +125NC8 SO —
MAX44246AUA+ -40NC to +125NC 8 FMAX —
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 13
© 2015 Maxim Integrated The Maxim logo and Maxim Integrated are trademarks of Maxim Integrated Products, Inc.
MAX44241/MAX44243/MAX44246
36V, Low-Noise, Precision,
Single/Quad/Dual Op Amps
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 7/12 Initial release —
1 9/12 Revised the Electrical Characteristics and the Typical Operating Characteristics.1, 2, 3, 5
2 2/13 Revised the Typical Operating Characteristics. 8
3 5/13 Updated General Description, Typical Application Circuit, and Pin Description. 1, 9
4 9/13 Added the MAX44241/MAX44243 to the data sheet. Revised the Typical Operating
Circuit.1–13
5 1/14 Revised Electrical Characteristics and the Typical Operating Characteristics.2, 5
6 12/14 Revised Benefits and Features section. 1
7 4/15 Revised Ordering Information 13
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