19-2424; Rev 2; 5/06
Ultra-Low Offset/Drift, Low-Noise,
Precision SOT23 Amplifiers
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 600µA. An active-
low shutdown mode decreases supply current to 0.1µA.
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, 6-pin TDFN and SOT23 packages.
♦
Ultra-Low, 0.1µV Offset Voltage
2.0µV (max) at +25°C
2.5µV (max) at -40°C to +85°C
3.5µV (max) at -40°C to +125°C
♦
Low 10nV/
o
C Drift
♦
Specified over the -40
o
C to +125
o
C Automotive
Temperature Range
♦
Low Noise: 1.5µV
P-P
from DC to 10Hz
♦
150dB A
VOL
, 140dB PSRR, 140dB CMRR
♦
High Gain-Bandwidth Product
1MHz (MAX4238)
6.5MHz (MAX4239)
♦
0.1µA Shutdown Mode
♦
Rail-to-Rail Output (R
L
= 1kΩ)
♦
Low 600µA Supply Current
♦
Ground-Sensing Input
♦
Single 2.7V to 5.5V Supply Voltage Range
♦
Available in a Space-Saving 6-Pin SOT23 and
TDFN Packages
Features
MAX4238/MAX4239
Applications
Thermocouples
Strain Gauges
Electronic Scales
Medical Instrumentation
Instrumentation Amplifiers
Ordering Information
Typical Application Circuit
PART
5V
PIN-
PACKAGE
6 SOT23-6
8 SO
6 TDFN-EP*
6 SOT23-6
8 SO
6 TDFN-EP*
TOP
MARK
AAZZ
—
+ANG
ABAA
—
+ANH
PKG
CODE
U6F-6
S8-4
T633-2
U6F-6
S8-4
T633-2
MAX4238AUT-T
MAX4238ASA
18kΩ
MAX4238ATT+T
MAX4239AUT-T
ADC
360Ω
STRAIN GAUGE
A
V
= 100
AIN
MAX4239ASA
MAX4239ATT+T
18kΩ
MAX4238/
MAX4239
Note:
All devices are specified over the -40°C to +125°C oper-
ating temperature range.
+Denotes
lead-free package.
*EP
= Exposed paddle.
Selector Guide
PART
MAX4238
MAX4239
MINIMUM STABLE
GAIN
1V/V
10V/V
GAIN
BANDWIDTH
(MHz)
1
6.5
Pin Configurations appear at end of data sheet.
________________________________________________________________
Maxim Integrated Products
1
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.
Ultra-Low Offset/Drift, Low-Noise,
Precision SOT23 Amplifiers
MAX4238/MAX4239
ABSOLUTE MAXIMUM RATINGS
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
6-Pin TDFN-EP (derate 18.2mW above +70°C) .........1454mW
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
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
(2.7V
≤
V
CC
≤
5.5V, V
CM
= GND = 0V, V
OUT
= V
CC
/2, R
L
= 10kΩ connected to V
CC
/2,
SHDN
= V
CC
,
T
A
= +25
°
C,
unless otherwise noted.)
PARAMETER
Input Offset Voltage
Long-Term Offset Drift
Input Bias Current
Input Offset Current
Peak-to-Peak Input Noise Voltage
Input Voltage-Noise Density
Common-Mode Input
Voltage Range
Common-Mode Rejection Ratio
Power-Supply Rejection Ratio
I
B
I
OS
e
nP-P
e
n
V
CM
CMRR
PSRR
(Note 2)
(Note 2)
R
S
= 100Ω, 0.01Hz to 10Hz
f = 1kHz
Inferred from CMRR test
-0.1V
≤
V
CM
≤
V
CC
- 1.3V (Note 1)
2.7V
≤
V
CC
≤
5.5V (Note 1)
0.05V
≤
V
OUT
≤
V
CC
- 0.05V
(Note 1)
Large-Signal Voltage Gain
A
VOL
0.1V
≤
V
OUT
≤
V
CC
- 0.1V
(Note 1)
R
L
= 10kΩ
Output Voltage Swing
V
OH
/V
OL
R
L
= 1kΩ
Output Short-Circuit Current
Output Leakage Current
Slew Rate
Gain-Bandwidth Product
Minimum Stable Closed-Loop
Gain
GBWP
To either supply
0
≤
V
OUT
≤
V
CC
,
SHDN
= GND (Note 2)
V
CC
= 5V, C
L
= 100pF,
V
OUT
= 2V step
R
L
= 10kΩ, C
L
= 100pF,
measured at f = 100kHz
R
L
= 10kΩ, C
L
= 100pF,
phase margin = 60
o
MAX4238
MAX4239
MAX4238
MAX4239
MAX4238
MAX4239
R
L
= 10kΩ
R
L
= 1kΩ
V
CC
- V
OH
V
OL
V
CC
- V
OH
V
OL
GND
- 0.1
120
120
125
125
140
140
150
dB
145
4
4
35
35
40
0.01
0.35
1.6
1
6.5
1
10
1
10
10
50
50
mA
µA
V/µs
MHz
V/V
mV
SYMBOL
V
OS
(Note 1)
CONDITIONS
MIN
TYP
0.1
50
1
2
1.5
30
V
CC
- 1.3
MAX
2
UNITS
µV
nV/1000hr
pA
pA
µV
P-P
NV/√Hz
V
dB
dB
2
_______________________________________________________________________________________
Ultra-Low Offset/Drift, Low-Noise,
Precision SOT23 Amplifiers
ELECTRICAL CHARACTERISTICS (continued)
(2.7V
≤
V
CC
≤
5.5V, V
CM
= GND = 0V, V
OUT
= V
CC
/2, R
L
= 10kΩ connected to V
CC
/2,
SHDN
= V
CC
,
T
A
= +25
°
C,
unless otherwise noted.)
PARAMETER
Maximum Closed-Loop Gain
SYMBOL
CONDITIONS
R
L
= 10kΩ, C
L
= 100pF,
phase margin = 60
o
MAX4238
MAX4239
0.1% (10 bit)
Settling Time
-1V step
0.025% (12 bit)
0.006% (14 bit)
0.0015% (16 bit)
0.1% (10 bit)
Overload Recovery Time
A
V
= 10
(Note 4)
0.025% (12 bit)
0.006% (14 bit)
0.0015% (16 bit)
0.1% (10 bit)
Startup Time
A
V
= 10
0.025% (12 bit)
0.006% (14 bit)
0.0015% (16 bit)
Supply Voltage Range
Supply Current
Shutdown Logic-High
Shutdown Logic-Low
Shutdown Input Current
V
CC
I
CC
V
IH
V
IL
0V
≤
V
SHDN
≤
V
CC
0.1
Inferred by PSRR test
SHDN
= V
CC
, no load, V
CC
= 5.5V
SHDN
= GND, V
CC
= 5.5V
2.2
0.8
1
2.7
600
0.1
MIN
TYP
1000
6700
0.5
1.0
1.7
2.3
3.3
4.1
4.9
5.7
1.8
2.6
3.4
4.3
5.5
850
1
V
µA
V
V
µA
ms
ms
ms
MAX
UNITS
V/V
MAX4238/MAX4239
_______________________________________________________________________________________
3
Ultra-Low Offset/Drift, Low-Noise,
Precision SOT23 Amplifiers
MAX4238/MAX4239
ELECTRICAL CHARACTERISTICS
(2.7V
≤
V
CC
≤
5.5V, V
CM
= GND = 0V, V
OUT
= V
CC
/2, R
L
= 10kΩ connected to V
CC
/2,
SHDN
= V
CC
,
T
A
= -40
°
C to +125
°
C,
unless other-
wise noted.) (Note 5)
PARAMETER
Input Offset Voltage
Input Offset Drift
Common-Mode Input Voltage
Range
Common-Mode Rejection Ratio
Power-Supply Rejection Ratio
SYMBOL
V
OS
TCV
OS
V
CM
(Note 1)
(Note 1)
Inferred from CMRR test
GND - 0.05V
≤
T
A
= -40°C to +85°C
V
CM
≤
V
CC
-
1.4V (Note 1) T
A
= -40°C to +125°C
2.7V
≤
V
CC
≤
5.5V (Note 1)
R
L
= 10kΩ,
T
A
= -40°C to +85°C
0.1V
≤
V
OUT
≤
V
CC
- 0.1V
T
A
= -40°C to +125°C
(Note 1)
Large-Signal Voltage Gain
A
VOL
R
L
= 1kΩ
(Note 1)
0.1V
≤
V
OUT
≤
V
CC
- 0.1V,
T
A
= -40°C to +85°C
0.2V
≤
V
OUT
≤
V
CC
- 0.2V,
T
A
= -40°C to +125°C
V
CC
- V
OH
V
OL
V
CC
- V
OH
V
OL
GND
- 0.05
115
dB
90
120
125
dB
95
120
dB
80
20
20
100
100
2
2.7
5.5
900
2
2.2
0.7
0V
≤
V
SHDN
≤
V
CC
2
µA
V
µA
V
V
µA
mV
dB
CONDITIONS
T
A
= -40°C to +85°C
T
A
= -40°C to +125°C
10
V
CC
- 1.4
MIN
TYP
MAX
2.5
3.5
UNITS
µV
nV/°C
V
CMRR
PSRR
R
L
= 10kΩ
Output Voltage Swing
V
OH
/V
OL
R
L
= 1kΩ
Output Leakage Current
Supply Voltage Range
Supply Current
Shutdown Logic High
Shutdown Logic Low
Shutdown Input Current
V
CC
I
CC
V
IH
V
IL
0V
≤
V
OUT
≤
V
CC
,
SHDN
= GND
(Note 3)
Inferred by PSRR test
SHDN
= V
CC
, no load, V
CC
= 5.5V
SHDN
= GND, V
CC
= 5.5V
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.
4
_______________________________________________________________________________________
Ultra-Low Offset/Drift, Low-Noise,
Precision SOT23 Amplifiers
MAX4238/MAX4239
Typical Operating Characteristics
(V
CC
= 5V, VCM = 0V, R
L
= 10kΩ connected to V
CC
/2,
SHDN
= V
CC
, T
A
= +25°C, unless otherwise noted.)
OFFSET VOLTAGE
vs. COMMON-MODE VOLTAGE
MAX4238/39 toc02
MAX4238/39 toc03
INPUT OFFSET DISTRIBUTION
MAX4238/39 toc01
OFFSET VOLTAGE vs. SUPPLY VOLTAGE
0.4
T
A
= +125°C
OFFSET VOLTAGE (μV)
0.2
T
A
= +25°C
0
T
A
= -40°C
0.4
50
PERCENTAGE OF UNITS (%)
40
OFFSET VOLTAGE (μV)
0.2
T
A
= +125°C
T
A
= +25°C
T
A
= -40°C
30
0
20
10
-0.2
-0.2
0
-1.5 -1.2 -0.9 -0.6 -0.3 0
0.3 0.6 0.9 1.2 1.5
OFFSET VOLTAGE (μV)
-0.4
2.7
3.4
4.1
4.8
5.5
SUPPLY VOLTAGE (V)
-0.4
0
0.9
1.8
2.7
3.6
COMMON-MODE VOLTAGE (V)
OUTPUT HIGH VOLTAGE
vs. OUTPUT SOURCE CURRENT
V
OH
= V
CC
- V
OUT
0.25
OUTPUT HIGH VOLTAGE (V)
0.20
V
CC
= 2.7V
0.15
V
CC
= 5V
0.10
0.05
0
0
5
10
15
20
SOURCE CURRENT (mA)
MAX4238/39 toc04
OUTPUT LOW VOLTAGE
vs. OUTPUT SINK CURRENT
MAX4238/39 toc05
MAX4238
GAIN AND PHASE vs. FREQUENCY
80
60
40
20
0
-20
-40
-60
-80
-100
-120
-140
-160
-180
MAX4238/39 toc06
0.30
0.35
0.30
OUTPUT LOW VOLTAGE (V)
0.25
V
CC
= 2.7V
0.20
0.15
0.10
0.05
0
0
5
10
SINK CURRENT (mA)
15
V
CC
= 5V
GAIN AND PHASE (dB/DEGREES)
V
CC
= 5V
GAIN = 60dB
R
L
= 10kΩ
C
L
= 0pF
100
1k
10k
100k
1M
10M
20
FREQUENCY (Hz)
MAX4238
GAIN AND PHASE vs. FREQUENCY
80
60
40
20
0
-20
-40
-60
-80
-100
-120
-140
-160
-180
80
60
40
20
0
-20
-40
-60
-80
-100
-120
-140
-160
-180
MAX4238/39 toc07
MAX4238
GAIN AND PHASE vs. FREQUENCY
80
60
40
20
0
-20
-40
-60
-80
-100
-120
-140
-160
-180
MAX4238/39 toc08
MAX4238
GAIN AND PHASE vs. FREQUENCY
MAX4238/39 toc09
GAIN AND PHASE (dB/DEGREES)
GAIN AND PHASE (dB/DEGREES)
V
CC
= 5V
GAIN = 60dB
R
L
= 10kΩ
C
L
= 100pF
100
1k
10k
100k
1M
10M
V
CC
= 5V
GAIN = 40dB
R
L
= 10kΩ
C
L
= 0pF
100
1k
10k
100k
1M
10M
GAIN AND PHASE (dB/DEGREES)
V
CC
= 5V
GAIN = 40dB
R
L
= 10kΩ
C
L
= 68pF
100
1k
10k
100k
1M
10M
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQUENCY (Hz)
_______________________________________________________________________________________
5
