General Description
The MAX4238/MAX4239 are low-noise, low-drift, ultra-
high precision amplifiers that offer near-zero DC offset
and drift through the use of patented autocorrelating
zeroing techniques. This method constantly measures
and compensates the input offset, eliminating drift over
time and temperature and the effect of 1/f noise. Both
devices feature Rail-to-Rail
outputs, operate from a
single 2.7V to 5.5V supply, and consume only 600A.
An active-low shutdown mode decreases supply cur-
rent to 0.1A.
The MAX4238 is unity-gain stable with a gain-band-
width product of 1MHz, while the decompensated
MAX4239 is stable with A
V
10V/V and a GBWP of
6.5MHz. The MAX4238/MAX4239 are available in 8-pin
narrow SO and 6-pin SOT23 packages.
Applications
Thermocouples
Strain Gauges
Electronic Scales
Medical Instrumentation
Instrumentation Amplifiers
Features
o Ultra-Low, 0.1V Offset Voltage
2.0V (max) at +25C
2.5V (max) at -40C to +85C
3.5V (max) at -40C to +125C
o Low 10nV/
o
C Drift
o Specified over the -40
o
C to +125
o
C Automotive
Temperature Range
o Low Noise: 1.5V
P-P
from DC to 10Hz
o 150dB A
VOL
, 140dB PSRR, 140dB CMRR
o High Gain-Bandwidth Product
1MHz (MAX4238)
6.5MHz (MAX4239)
o 0.1A Shutdown Mode
o Rail-to-Rail Output (R
L
= 1k
)
o Low 600A Supply Current
o Ground-Sensing Input
o Single 2.7V to 5.5V Supply Voltage Range
o Available in a Space-Saving 6-Pin SOT23 Package
MAX4238/MAX4239
Ultra-Low Offset/Drift, Low-Noise,
Precision SOT23 Amplifiers
________________________________________________________________ Maxim Integrated Products
1
MAX4238/
MAX4239
360
STRAIN GUAGE
18k
18k
AIN
5V
A
V
= 100
ADC
Typical Application Circuit
19-2424; Rev 1; 12/02
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim's website at www.maxim-ic.com.
Pin Configurations appear at end of data sheet.
Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd.
Ordering Information
PART
TEMP RANGE
PIN-
PACKAGE
TOP
MARK
MAX4238AUT-T
-40
o
C to +125
o
C
6 SOT23-6
AAZZ
MAX4238ASA
-40
o
C to +125
o
C
8 SO
--
MAX4239AUT-T
-40
o
C to +125
o
C
6 SOT23-6
ABAA
MAX4239ASA
-40
o
C to +125
o
C
8 SO
--
Selector Guide
PART
MINIMUM STABLE
GAIN
GAIN
BANDWIDTH
(MHz)
MAX4238
1V/V
1
MAX4239
10V/V
6.5
MAX4238/MAX4239
Ultra-Low Offset/Drift, Low-Noise,
Precision SOT23 Amplifiers
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(2.7V
V
CC
5.5V, V
CM
= GND = 0V, V
OUT
= V
CC
/2, R
L
= 10k
connected to V
CC
/2, SHDN = V
CC
, T
A
= +25
C,
unless otherwise noted.)
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.
Power-Supply Voltage (V
CC
to GND).......................................6V
All Other Pins .................................(GND - 0.3V) to (V
CC
+ 0.3V)
Output Short-Circuit Duration
(OUT shorted to V
CC
or GND) ...............................Continuous
Continuous Power Dissipation (T
A
= +70
C)
6-Pin Plastic SOT23 (derate 9.1mW/
C above +70
C).727mW
8-Pin Plastic SO (derate 5.88mW/
C above +70
C).....471mW
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
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Input Offset Voltage
V
OS
(Note 1)
0.1
2
V
Long-Term Offset Drift
50
nV/1000hr
Input Bias Current
I
B
(Note 2)
1
pA
Input Offset Current
I
OS
(Note 2)
2
pA
Input Noise Voltage
e
nP-P
R
S
= 100
, 0.01Hz to 10Hz
1.5
V
P-P
Common-Mode Input
Voltage Range
V
CM
Inferred from CMRR test
GND
- 0.1
V
CC
-
1.3
V
Common-Mode Rejection Ratio
CMRR
-0.1V
V
CM
V
CC
- 1.3V (Note 1)
120
140
dB
Power-Supply Rejection Ratio
PSRR
2.7V
V
CC
5.5V (Note 1)
120
140
dB
0.05V
V
OU T
V
C C
- 0.05V
( N ote 1)
R
L
= 10k
125
150
Large-Signal Voltage Gain
A
VOL
0.1V
V
OUT
V
CC
- 0.1V
(Note 1)
R
L
= 1k
125
145
dB
V
CC
- V
OH
4
10
R
L
= 10k
V
OL
4
10
V
CC
- V
OH
35
50
Output Voltage Swing
V
OH
/V
OL
R
L
= 1k
V
OL
35
50
mV
Output Short-Circuit Current
To either supply
40
mA
Output Leakage Current
0
V
OUT
V
CC
, SHDN = GND (Note 2)
0.01
1
A
MAX4238
0.35
Slew Rate
V
CC
= 5V, C
L
= 100pF,
V
OUT
= 2V step
MAX4239
1.6
V/s
MAX4238
1
Gain-Bandwidth Product
GBWP
R
L
= 10k
, C
L
= 100pF,
measured at f = 100kHz
MAX4239
6.5
MHz
MAX4238
1
Minimum Stable Closed-Loop
Gain
R
L
= 10k
, C
L
= 100pF,
phase margin = 60
o
MAX4239
10
V/V
MAX4238/MAX4239
Ultra-Low Offset/Drift, Low-Noise,
Precision SOT23 Amplifiers
_______________________________________________________________________________________
3
ELECTRICAL CHARACTERISTICS (continued)
(2.7V
V
CC
5.5V, V
CM
= GND = 0V, V
OUT
= V
CC
/2, R
L
= 10k
connected to V
CC
/2, SHDN = V
CC
, T
A
= +25
C,
unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX4238
1000
Maximum Closed-Loop Gain
R
L
= 10k
, C
L
= 100pF,
phase margin = 60
o
MAX4239
6700
V/V
0.1% (10 bit)
0.5
0.025% (12 bit)
1.0
0.006% (14 bit)
1.7
Settling Time
-1V step
0.0015% (16
2.3
ms
0.1% (10 bit)
3.3
0.025% (12 bit)
4.1
0.006% (14 bit)
4.9
Overload Recovery Time
A
V
= 10
(Note 4)
0.0015% (16
5.7
ms
0.1% (10 bit)
1.8
0.025% (12 bit)
2.6
0.006% (14 bit)
3.4
Startup Time
A
V
= 10
0.0015% (16
4.3
ms
Supply Voltage Range
V
CC
Inferred by PSRR test
2.7
5.5
V
SHDN = V
CC
, no load, V
CC
= 5.5V
600
850
Supply Current
I
CC
SHDN = GND, V
CC
= 5.5V
0.1
1
A
Shutdown Logic High
V
IH
2.2
V
Shutdown Logic Low
V
IL
0.8
V
Shutdown Input Current
0V
V
SHDN
V
CC
0.1
1
A
MAX4238/MAX4239
Ultra-Low Offset/Drift, Low-Noise,
Precision SOT23 Amplifiers
4
_______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS
(2.7V
V
CC
5.5V, V
CM
= GND = 0V, V
OUT
= V
CC
/2, R
L
= 10k
connected to V
CC
/2, SHDN = V
CC
, T
A
= -40
C to +125
C, unless other-
wise noted.) (Note 5)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
T
A
= -40C to +85C
2.5
Input Offset Voltage
V
OS
(Note 1)
T
A
= -40C to +125C
3.5
V
Input Offset Drift
TCV
OS
(Note 1)
10
nV/C
Common-Mode Input Voltage
Range
V
CM
Inferred from CMRR test
GND -
0.05
V
CC
-
1.4
V
T
A
= -40C to +85C
115
Common-Mode Rejection Ratio
CMRR
GN D - 0.05V
V
C M
V
C C
-
1.4V ( N ote 1)
T
A
= -40C to +125C
90
dB
Power-Supply Rejection Ratio
PSRR
2.7V
V
CC
5.5V (Note 1)
120
dB
T
A
= -40C to +85C
125
R
L
= 10k
,
0.1V
V
OUT
V
CC
- 0.1V
(Note 1)
T
A
= -40C to +125C
95
dB
0.1V
V
OUT
V
CC
- 0.1V,
T
A
= -40C to +85C
120
Large-Signal Voltage Gain
A
VOL
R
L
= 1k
(Note 1)
0.2V
V
OUT
V
CC
- 0.2V,
T
A
= -40C to +125C
80
dB
V
CC
- V
OH
20
R
L
= 10k
V
OL
20
V
CC
- V
OH
100
Output Voltage Swing
V
OH
/V
OL
R
L
= 1k
V
OL
100
mV
Output Leakage Current
0V
V
OUT
V
CC
, SHDN = GND (Note
2
A
Supply Voltage Range
V
CC
Inferred by PSRR test
2.7
5.5
V
SHDN = V
CC
, no load, V
CC
= 5.5V
900
Supply Current
I
CC
SHDN = GND, V
CC
= 5.5V
2
A
Shutdown Logic High
V
IH
2.2
V
Shutdown Logic Low
V
IL
0.7
V
Shutdown Input Current
0V
V
SHDN
V
CC
2
A
Note 1: Guaranteed by design. Thermocouple and leakage effects preclude measurement of this parameter during production
testing. Devices are screened during production testing to eliminate defective units.
Note 2: IN+ and IN- are gates to CMOS transistors with typical input bias current of 1pA. CMOS leakage is so small that it is
impractical to test and guarantee in production. Devices are screened during production testing to eliminate defective units.
Note 3: Leakage does not include leakage through feedback resistors.
Note 4: Overload recovery time is the time required for the device to recover from saturation when the output has been
driven to either rail.
Note 5: Specifications are 100% tested at T
A
= +25
C, unless otherwise noted. Limits over temperature are guaranteed by design.
MAX4238/MAX4239
Ultra-Low Offset/Drift, Low-Noise,
Precision SOT23 Amplifiers
_______________________________________________________________________________________
5
Typical Operating Characteristics
(V
CC
= 5V, VCM = 0V, R
L
= 10k
connected to V
CC
/2, SHDN = V
CC
, T
A
= +25C, unless otherwise noted.)
MAX4239
GAIN AND PHASE vs. FREQUENCY (T
A
= +25
C)
MAX4238/39 toc09
FREQUENCY (Hz)
GAIN AND PHASE (dB/DEGREES)
1M
100k
10k
1k
-160
-140
-120
-100
-80
-60
-40
-20
0
20
40
60
80
-180
0.1k
10M
V
CC
= 5V
A
V
= 1000V/V
C
L
= 100pF
R
L
= 10k
MAX4238
GAIN AND PHASE vs. FREQUENCY (T
A
= -40
C)
MAX4238/39 toc07
FREQUENCY (Hz)
GAIN AND PHASE (dB/DEGREES)
1M
100k
10k
1k
-160
-140
-120
-100
-80
-60
-40
-20
0
20
40
60
80
-180
0.1k
10M
V
CC
= 5V
A
V
= 1000V/V
C
L
= 100pF
R
L
= 10k
MAX4238
GAIN AND PHASE vs. FREQUENCY (T
A
= +25
C)
MAX4238/39 toc06
FREQUENCY (Hz)
GAIN AND PHASE (dB/DEGREES)
1M
100k
10k
1k
-160
-140
-120
-100
-80
-60
-40
-20
0
20
40
60
80
-180
0.1k
10M
V
CC
= 5V
A
V
= 1000V/V
C
L
= 100pF
R
L
= 10k
OUTPUT LOW VOLTAGE
vs. OUTPUT SINK CURRENT
MAX4238/39 toc05
SINK CURRENT (mA)
OUTPUT LOW VOLTAGE (V)
15
10
5
0.05
0.10
0.15
0.20
0.25
0.35
0.30
0
0
20
V
CC
= 2.7V
V
CC
= 5V
OUTPUT HIGH VOLTAGE
vs. OUTPUT SOURCE CURRENT
MAX4238/39 toc04
SOURCE CURRENT (mA)
OUTPUT HIGH VOLTAGE (V)
15
10
5
0.05
0.10
0.15
0.20
0.25
0.30
0
0
20
V
OH
= V
CC
- V
OUT
V
CC
= 2.7V
V
CC
= 5V
OFFSET VOLTAGE
vs. COMMON-MODE VOLTAGE
MAX4238/39 toc03
COMMON-MODE VOLTAGE (V)
OFFSET VOLTAGE (
V)
2.7
1.8
0.9
-0.2
0
0.2
0.4
-0.4
0
3.6
T
A
= +125
C
T
A
= +25
C
T
A
= -40
C
OFFSET VOLTAGE vs. SUPPLY VOLTAGE
MAX4238/39 toc02
SUPPLY VOLTAGE (V)
OFFSET VOLTAGE (
V)
4.8
4.1
3.4
-0.2
0
0.2
0.4
-0.4
2.7
5.5
T
A
= +125
C
T
A
= +25
C
T
A
= -40
C
INPUT OFFSET DISTRIBUTION
MAX4238/39 toc01
OFFSET VOLTAGE (
V)
PERCENTAGE OF UNITS (%)
1.5
1.2
0.9
0.6
0.3
0
-0.3
-0.6
-0.9
-1.2
-1.5
10
20
30
40
50
0
MAX4238
GAIN AND PHASE vs. FREQUENCY (T
A
= +125
C)
MAX4238/39 toc08
FREQUENCY (Hz)
GAIN AND PHASE (dB/DEGREES)
1M
100k
10k
1k
-160
-140
-120
-100
-80
-60
-40
-20
0
20
40
60
80
-180
0.1k
10M
V
CC
= 5V
A
V
= 1000V/V
C
L
= 100pF
R
L
= 10k
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