19-2110; Rev 0; 8/01
SOT23, Very High Precision, 3V/5V
Rail-to-Rail Op Amps
The MAX4236/MAX4237 are high-precision op amps
that feature an exceptionally low offset voltage and offset voltage temperature coefficient without using any
chopper techniques. The MAX4236 and MAX4237 have
a typical large-signal, open-loop voltage gain of 120dB.
These devices have an ultra-low input-bias current of
1pA. The MAX4236 is unity-gain stable with a gainbandwidth product of 1.7MHz, while the MAX4237 is
stable for closed-loop gains greater than 5V/V with a
gain-bandwidth product of 7.5MHz. Both devices have
a shutdown function in which the quiescent current is
reduced to less than 0.1µA, and the amplifier output is
forced into a high-impedance state.
The input common-mode range of the MAX4236/
MAX4237 extends below the negative supply range, and
the output swings Rail-to-Rail®. These features make the
amplifiers ideal for applications with +3V or +5V single
power supplies. The MAX4236/MAX4237 are specified for
the extended temperature range (-40°C to +85°C) and
are available in tiny SOT23, µMAX, and SO packages. For
greater accuracy, the A grade µMAX and SO packages
are tested to guarantee 20µV (max) offset voltage at
+25°C and less then 2µV/°C drift.
Applications
Strain Gauges
Features
♦ Ultra-Low Offset Voltage
20µV (max) at +25°C (Grade A)
50µV (max) at +25°C (Grade B, 6-Pin SOT23)
♦ Ultra-Low Offset Voltage Drift
2µV/°C (max) (Grade A)
4.5µV/°C (max) (Grade B, 6-Pin SOT23)
5.5µV/°C (max) (6-Pin SOT23)
♦ Ultra-Low 1pA Input Bias Current
♦ High Open-Loop Voltage Gain: 110dB (min)
(RL = 100kΩ)
♦ Compatible with +3V and +5V Single-Supply
Power Systems
♦ Ground Sensing: Input Common-Mode Range
Includes Negative Rail
♦ Rail-to-Rail Output Swing into a 1kΩ Load
♦ 350µA Quiescent Current
♦ Gain-Bandwidth Product
1.7MHz (MAX4236, AV = 1V/V)
7.5MHz (MAX4237, AV = 5V/V)
♦ 200pF Capacitive Load Handling Capability
♦ Shutdown Mode: 0.1µA Quiescent Current,
Places Output in a High-Impedance State
Piezoelectric Sensors
Thermocouple Amplifiers
♦ Available in Space-Saving SOT23 and µMAX
Packages
Electrochemical Sensors
Battery-Powered Instrumentation
Instrumentation Amplifiers
Ordering Information
Rail-to-Rail is a registered trademark of Nippon Motorola, Inc.
Pin Configurations
TOP VIEW
OUT 1
VEE 2
6
MAX4236
MAX4237
5
VCC
SHDN
4
IN-
TEMP. RANGE
PIN-PACKAGE
MAX4236EUT-T
-40°C to +85°C
6 SOT23-6
MAX4236AEUA
-40°C to +85°C
8 µMAX
MAX4236BEUA
-40°C to +85°C
8 µMAX
N.C.
1
8
SHDN
MAX4236AESA
-40°C to +85°C
8 SO
IN-
2
7
VCC
MAX4236BESA
-40°C to +85°C
8 SO
IN+
3
6
OUT
MAX4237EUT-T
-40°C to +85°C
6 SOT23-6
VEE
4
5
N.C.
MAX4237AEUA
-40°C to +85°C
8 µMAX
MAX4237BEUA
-40°C to +85°C
8 µMAX
MAX4237AESA
-40°C to +85°C
8 SO
MAX4237BESA
-40°C to +85°C
8 SO
MAX4236A/B
MAX4237A/B
SO-8/µMAX
IN+ 3
PART
SOT23-6
________________________________________________________________ Maxim Integrated Products
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.
1
MAX4236/MAX4237
General Description
MAX4236/MAX4237
SOT23, Very High Precision, 3V/5V
Rail-To-Rail Op Amps
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (VCC - VEE) ......................................-0.3V to +6V
Analog Input Voltage (IN+ or IN-) ....(VEE - 0.3V) to (VCC + 0.3V)
Logic Input Voltage (SHDN) ............(VEE - 0.3V) to (VCC + 0.3V)
Current into Any Pin ............................................................20mA
Output Short-Circuit Duration....Continuous to Either VCC or VEE
Continuous Power Dissipation (TA = +70°C)
6-Pin SOT23-6 (derate 8.7mW/°C above +70°C) .........696mW
8-Pin µMAX (derate 4.5mW/°C above +70°C) ..............362mW
8-Pin SO (derate 5.9mW/°C above +70°C)...................471mW
Operating Temperature Range ...........................-40°C to +85°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 (SO-8 and µMAX-8)
(VCC = +2.4V to +5.5V, VEE = 0, VCM = 0, VOUT = VCC/2, RL = 100kΩ to VCC/2, TA = TMIN to TMAX, unless otherwise noted. Typical
values are at VCC = +5V and TA = +25°C.) (Note 1)
PARAMETER
Supply Voltage Range
SYMBOL
VCC
CONDITIONS
MIN
Guaranteed by the PSRR test
2.4
VCC = +5V
Quiescent Supply Current
ICC
VCC = +3V
VCC = +5V,
Grade A
Input Offset Voltage
Input Offset Voltage Temperature
Coefficient
Input Bias Current
VOS
TCVOS
VCC = +5V,
Grade B
VCC = +5V
(Note 3)
TYP
MAX
UNITS
5.5
V
In normal mode
350
In shutdown mode
0.1
440
2
In normal mode
350
440
In shutdown mode
0.1
2
TA = +25oC
±5
±20
TA = TMIN to TMAX
±150
o
TA = +25 C
±5
TA = TMIN to TMAX
±50
µA
µV
±340
Grade A
±0.6
±2
Grade B
±0.6
±4.5
±500
µV/°C
IB
(Note 2)
±1
Input Offset Current
IOS
(Note 2)
±1
pA
Input Resistance
RIN
Differential or common mode
1000
MΩ
Input Common-Mode Voltage
VCM
Guaranteed by the CMRR test
Common-Mode Rejection Ratio
CMRR
VCC = +5V;
-0.15V ≤ VCM ≤
(VCC - 1.2V)
VCC = +3.0V;
-0.15V ≤ VCM ≤
(VCC - 1.2V)
Power-Supply Rejection Ratio
2
PSRR
VCC = +2.4V to
+5.5V
-0.15
TA = +25oC
84
TA = TMIN to TMAX
80
TA = +25oC
82
TA = TMIN to TMAX
78
o
TA = +25 C
97
TA = TMIN to TMAX
95
VCC - 1.2
pA
V
102
dB
102
120
_______________________________________________________________________________________
dB
SOT23, Very High Precision, 3V/5V
Rail-To-Rail Op Amps
(VCC = +2.4V to +5.5V, VEE = 0, VCM = 0, VOUT = VCC/2, RL = 100kΩ to VCC/2, TA = TMIN to TMAX, unless otherwise noted. Typical
values are at VCC = +5V and TA = +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
VCC = +5V, RL
connected to
VCC/2,
TA = +25oC
VCC = +5V, RL
connected to
VCC/2,
TA = TMIN to
TMAX
Large-Signal Voltage Gain
MIN
TYP
RL = 100kΩ, VOUT =
15mV to (VCC - 50mV)
110
128
RL = 1kΩ, VOUT =
0.15V to (VCC - 0.3V)
105
114
RL = 100kΩ, VOUT =
15mV to (VCC - 50mV)
110
RL = 1kΩ,
VOUT = 0.15V
to (VCC - 0.3V)
100
VCC = +3V, RL
connected to
VCC/2,
TA = TMIN to
TMAX
RL = 100kΩ, VOUT =
15mV to (VCC - 50mV)
110
128
RL = 1kΩ,
VOUT = 0.15V
to (VCC - 0.3V)
100
114
RL = 100kΩ, VOUT =
15mV to (VCC - 50mV)
105
RL = 1kΩ,
VOUT = 0.15V
to (VCC - 0.3V)
95
VCC = +5V,
RL connected to VCC /2,
RL = 100kΩ
Gain-Bandwidth Product
2
10
VOL - VEE
3
10
VCC - VOH
150
250
VOL - VEE
50
100
mV
IOUT(SC)
GBWP
Shorted to VEE
10
Shorted to VCC
30
RL = ∞, CL = 5pF
Slew Rate
SR
VCC = +5V, VOUT = 4V step
Settling Time
tS
VOUT settling to within
0.01%
Total Harmonic Distortion
VCC - VOH
VOUT
VCC = +5V,
RL connected to VCC/2,
RL = 1kΩ
Output Short-Circuit Current
THD
UNITS
dB
AVOL
VCC = +3V, RL
connected to
VCC/2,
TA = +25oC
Output Voltage Swing
MAX
MAX4236
1.7
MAX4237
7.5
MAX4236
0.3
MAX4237
1.3
MAX4236
1
MAX4237
1
f = 5kHz, VOUT = 2Vp-p, VCC = +5V
RL = 10kΩ
0.001
mA
MHz
V/µs
µs
%
_______________________________________________________________________________________
3
MAX4236/MAX4237
ELECTRICAL CHARACTERISTICS (SO-8 and µMAX-8) (continued)
MAX4236/MAX4237
SOT23, Very High Precision, 3V/5V
Rail-To-Rail Op Amps
ELECTRICAL CHARACTERISTICS (SO-8 and µMAX-8) (continued)
(VCC = +2.4V to +5.5V, VEE = 0, VCM = 0, VOUT = VCC/2, RL = 100kΩ to VCC/2, TA = TMIN to TMAX, unless otherwise noted. Typical
values are at VCC = +5V and TA = +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Input Capacitance
CIN
f = 100kHz
7.5
Input Voltage Noise Density
en
f = 1kHz
14
nV/√Hz
f = 0.1Hz to 10Hz
0.2
µVp-p
Input Noise Voltage
enp-p
Capacitive Load Stability
CLOAD
Shutdown Mode Output
Leakage
IOUT(SH)
SHDN Logic Low
VIL
SHDN Logic High
VIH
SHDN Input Current
No sustained oscillations
MAX4236
200
MAX4237
200
Device in shutdown mode (SHDN = VEE)
VOUT = 0 to VCC
±0.01
pF
pF
±1.0
µA
0.3 ✕
VCC
V
0.7 ✕
VCC
V
SHDN = VEE or VCC
1
3
µA
Shutdown Delay Time
t(SH)
RL = 1kΩ
1
µs
Shutdown Recovery Time
t(EN)
RL = 1kΩ
4
µs
ELECTRICAL CHARACTERISTICS (SOT23-6)
(VCC = +2.4V to +5.5V, VEE = 0, VCM = 0, VOUT = VCC/2, RL = 100kΩ to VCC/2, TA = TMIN to TMAX, unless otherwise noted. Typical
values are at VCC = +5V and TA = +25°C.) (Note 1)
PARAMETER
Supply Voltage Range
SYMBOL
VCC
CONDITIONS
Guaranteed by the PSRR test
VCC = +5V
Quiescent Supply Current
ICC
VCC = +3V
Input Offset Voltage
Input Offset Voltage Temperature
Coefficient (Note 2)
Input Bias Current
VOS
VCC = +5V
TCVOS
VCC = +5V
MIN
TYP
2.4
440
0.1
2
In normal mode
350
440
In shutdown mode
0.1
2
TA = +25°C
±5
±50
TA = TMIN to TMAX
±600
±0.6
±5.5
±500
±1
(Note 2)
±1
Input Resistance
RIN
Differential or common mode
Input Common-Mode Voltage
VCM
Guaranteed by the CMRR test
VCC = +5V, -0.15V
≤ VCM ≤ (VCC - 1.2V)
VCC = +3.0V; -0.15V
≤ VCM ≤ (VCC - 1.2V)
4
V
350
(Note 2)
CMRR
5.5
In shutdown mode
IB
Common-Mode Rejection Ratio
UNITS
In normal mode
IOS
Input Offset Current
MAX
TA = +25°C
82
TA = TMIN to TMAX
80
TA = +25°C
82
TA = TMIN to TMAX
78
µV
µV/°C
pA
pA
1000
-0.15
µA
MΩ
VCC - 1.2
V
102
102
_______________________________________________________________________________________
dB
SOT23, Very High Precision, 3V/5V
Rail-To-Rail Op Amps
(VCC = +2.4V to +5.5V, VEE = 0, VCM = 0, VOUT = VCC/2, RL = 100kΩ to VCC/2, TA = TMIN to TMAX, unless otherwise noted. Typical
values are at VCC = +5V and TA = +25°C.) (Note 1)
PARAMETER
Power-Supply Rejection Ratio
SYMBOL
PSRR
CONDITIONS
VCC = +2.4V to
+5.5V
VCC = +5V, RL
connected to
VCC/2,
TA = +25°C
VCC = +5V, RL
connected to
VCC/2,
TA = TMIN to
TMAX
Large-Signal Voltage Gain
AVOL
VCC = +3V, RL
connected to
VCC/2,
TA = +25°C
VCC = +3V, RL
connected to
VCC/2,
TA = TMIN to
TMAX
MIN
TYP
TA = +25°C
97
120
TA = TMIN to TMAX
95
RL = 100kΩ,
VOUT = 15mV to
(VCC - 50mV)
110
128
RL = 1kΩ,
VOUT = 0.15V
to (VCC - 0.3V)
100
114
RL = 100kΩ, VOUT =
15mV to (VCC - 50mV)
110
RL = 1kΩ,
VOUT = 0.15V to
(VCC - 0.3V)
95
RL = 100kΩ,
VOUT = 15mV to
(VCC - 50mV)
110
128
RL = 1kΩ,
VOUT = 0.15V to
(VCC - 0.3V)
100
114
RL = 100kΩ,
VOUT = 15mV to
(VCC - 50mV)
105
RL = 1kΩ,
VOUT = 0.15V to
(VCC - 0.3V)
95
VCC = +5V,
RL connected to VCC/2,
RL = 100kΩ
Output Voltage Swing
Gain-Bandwidth Product
Slew Rate
dB
VCC - VOH
2
10
VOL - VEE
3
10
VCC - VOH
150
250
VOL - VEE
50
100
mV
Shorted to VEE
10
Shorted to VCC
30
mA
IOUT(SC)
GBWP
SR
UNITS
dB
VOUT
VCC = +5V,
RL connected to VCC/2,
RL = 1kΩ
Output Short-Circuit Current
MAX
RL = ∞, CL = 15pF
VCC = +5V,
VOUT = 4V step
MAX4236
1.7
MAX4237
7.5
MAX4236
0.3
MAX4237
1.3
MHz
V/µs
_______________________________________________________________________________________
5
MAX4236/MAX4237
ELECTRICAL CHARACTERISTICS (SOT23-6) (continued)
ELECTRICAL CHARACTERISTICS (SOT23-6) (continued)
(VCC = +2.4V to +5.5V, VEE = 0, VCM = 0, VOUT = VCC/2, RL = 100kΩ to VCC/2, TA = TMIN to TMAX, unless otherwise noted. Typical
values are at VCC = +5V and TA = +25°C.) (Note 1)
PARAMETER
SYMBOL
Settling Time
CONDITIONS
tS
VOUT settling to within 0.01%
MIN
MAX4236
1
1
THD
f = 5kHz, VOUT = 2Vp-p, VCC = +5V
RL = 10kΩ
Input Capacitance
CIN
f = 100kHz
en
Input Voltage Noise Density
Input Noise Voltage
enp-p
Capacitive Load Stability
CLOAD
Shutdown Mode Output
Leakage
VIL
SHDN Logic High
VIH
MAX
UNITS
µs
0.001
%
7.5
pF
f = 1kHz
14
nV/√Hz
f = 0.1Hz to 10Hz
0.2
µVp-p
MAX4236
200
MAX4237
200
No sustained oscillations
pF
Device in shutdown mode (SHDN = VEE)
VOUT = 0 to VCC
IOUT(SH)
SHDN Logic Low
TYP
MAX4237
Total Harmonic Distortion
±0.01
±1.0
µA
0.3 x VCC
V
0.7 x VCC
SHDN Input Current
V
SHDN = VEE or VCC
1
Shutdown Delay Time
t(SH)
RL = 1kΩ
1
µs
Shutdown Recovery Time
t(EN)
RL = 1kΩ
4
µs
3
µA
Note 1: All devices are 100% production tested at TA = +25°C; all specifications over temperature are guaranteed by design,
unless otherwise specified.
Note 2: Guaranteed by design, not production tested.
Note 3: Maxim specification limits for the temperature coefficient of the offset voltage (TCVOS) are 100% tested for the A-grade, 8pin SO and µMAX packages.
Typical Operating Characteristics
(VCC = +5V, VEE = 0, VCM = VCC/2, RL = 100kΩ to VCC/2, TA = +25°C, unless otherwise noted.)
TCVOS DISTRIBUTION
20
PERCENT OF UNITS (%)
14
12
10
8
6
4
VCC = 5V
15
10
5
40
20
0
-20
-40
-60
2
-80
0
0
-10 -8 -6 -4
-2
0
2
VOS (µV)
6
60
OFFSET VOLTAGE (µV)
VCC = 5V
OFFSET VOLTAGE vs. TEMPERATURE
80
MAX4236 toc02
MAX 4236 toc01
16
25
MAX4236 toc02
VOS DISTRIBUTION
18
PERCENT OF UNITS (%)
MAX4236/MAX4237
SOT23, Very High Precision, 3V/5V
Rail-To-Rail Op Amps
4
6
8
10
-2.0 -1.5 -1.0 -0.5
0
0.5
TCVOS (µV/°C)
1.0 1.5
2.0
-50
-25
0
25
75
50
TEMPERATURE (°C)
_______________________________________________________________________________________
100
125
SOT23, Very High Precision, 3V/5V
Rail-To-Rail Op Amps
MAX4236/MAX4237
Typical Operating Characteristics (continued)
(VCC = +5V, VEE = 0, VCM = VCC/2, RL = 100kΩ to VCC/2, TA = +25°C, unless otherwise noted.)
COMMON-MODE REJECTION RATIO
vs. COMMON-MODE INPUT VOLTAGE
60
40
20
0
80
60
40
20
1.0
1.5
2.0
2.5
3.0
1
2
3
4
40
20
0.01
5
COMMON-MODE INPUT VOLTAGE (V)
COMMON-MODE REJECTION RATIO
vs. FREQUENCY (VCC = 3V)
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY (VCC = 5V)
MAX4236 toc08
100
GAIN (dB)
PSSR (dB)
60
0.1
1
10
100
1000 10,000
0.1
1
10
FREQUENCY (kHz)
60
40
VCC = 5V/3V
CL = 15pF/200pF
100
1000
-20
0.001 0.01 0.1
80
20
40
40
VCC = 5V/3V
CL = 15pF/200pF
20
10
0
100 1000 10,000 100,000
VOUT = 2Vp-p
0.1
THD + NOISE (%)
60
INPUT VOLTAGE NOISE (nV√Hz)
60
PHASE (DEGREES)
PHASE
100
1
MAX4236 toc11
25
1
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
INPUT VOLTAGE NOISE vs. FREQUENCY
100
20
FREQUENCY (kHz)
140
GAIN
10,000
FREQUENCY (kHz)
MAX4236
OPEN-LOOP GAIN/PHASE
vs. FREQUENCY
MAX4236 toc10
120
60
0
0
0.01
20
GAIN
80
40
20
0
80
80
20
20
100
100
40
40
1000 10,000
PHASE
120
80
60
1
10
100
FREQUENCY (kHz)
140
100
80
0.1
MAX4237
OPEN-LOOP GAIN/PHASE
vs. FREQUENCY
MAX4236 toc09
120
MAX4236 toc07
120
MAX4236 toc06
60
0
0
COMMON-MODE INPUT VOLTAGE (V)
140
GAIN (dB)
80
0
0.5
0
COMMON-MODE REJECTION RATIO (dB)
100
100
15
10
0.01
0.001
5
0
-20
0.001 0.01
0.1
1
10
0
100 1000 10,000
FREQUENCY (kHz)
0.0001
0
0.01
0.1
1
FREQUENCY (kHz)
10
100
10
100
1k
10k
100k
FREQUENCY (Hz)
_______________________________________________________________________________________
7
PHASE (DEGREES)
80
120
120
MAX4236 toc12
100
VCC = 5V
COMMON-MODE REJECTION RATIO (dB)
120
140
MAX4236 toc05
VCC = 3V
COMMON-MODE REJECTION RATIO (dB)
MAX4236 toc04
COMMON-MODE REJECTION RATIO (dB)
140
COMMON-MODE REJECTION RATIO
vs. FREQUENCY (VCC = 5V)
COMMON-MODE REJECTION RATIO
vs. COMMON-MODE INPUT VOLTAGE
Typical Operating Characteristics (continued)
(VCC = +5V, VEE = 0, VCM = VCC/2, RL = 100kΩ to VCC/2, TA = +25°C, unless otherwise noted.)
360
+V = 5V
340
330
TA = -40°C
VCC = 5V, RL to VEE
TA = +25°C
335
VCC = 5V, RL to VCC
120
TA = +85°C
330
TA = +125°C
100
VCC = 3V, RL to VEE
325
VCC = 3V, RL to VCC
80
+V = 3V
320
RL = 1kΩ
140
GAIN (dB)
370
350
340
SUPPLY CURRENT (µA)
SUPPLY CURRENT (µA)
380
MAX4236 toc14
MAX4236 toc13
390
LARGE-SIGNAL GAIN vs. TEMPERATURE
SUPPLY CURRENT vs. SUPPLY VOLTAGE
345
MAX4236 toc15
SUPPLY CURRENT vs. TEMPERATURE
400
320
310
0
25
50
75
100
125
5.0
-50
5.5
-25
0
25
50
75
MAXIMUM OUTPUT VOLTAGE
vs. TEMPERATURE
OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE
15
10
VCC = 5V/3V, RL = 100kΩ
5
0
VCC = 5V, RL = 1kΩ
160
140
120
VCC = 3V, RL = 1kΩ
100
80
60
0
25
50
75
100
160
140
100
80
60
20
20
VCC = 5V/3V, RL = 100kΩ
-50
-25
0
25
50
75
100
VCC - VOH, RL to VCC
120
40
125
VOL - VEE, RL to VEE
0
3.0
125
3.5
4.0
4.5
5.0
SUPPLY VOLTAGE (V)
OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE
OUTPUT SOURCE CURRENT
vs. OUTPUT VOLTAGE
OUTPUT SOURCE CURRENT
vs. OUTPUT VOLTAGE
VOL - VEE
3.0
2.5
2.0
VCC - VOH
1.0
0.5
VCC = 5V
10
8
6
4
2
10
VCC = 3V
9
OUTPUT SOURCE CURRENT (mA)
3.5
12
OUTPUT SOURCE CURRENT (mA)
RL = 100kΩ
MAX4236 toc20
TEMPERATURE (°C)
MAX4236 toc19
TEMPERATURE (°C)
4.0
125
RL = 1kΩ
180
40
0
-25
MAX4236 toc17
180
100
200
OUTPUT VOLTAGE (mV)
20
200
MAXIMUM OUTPUT VOLTAGE (mV)
VCC = 3V, RL = 1kΩ
25
1.5
4.5
MINIMUM OUTPUT VOLTAGE
vs. TEMPERATURE
30
-50
4.0
TEMPERATURE (°C)
MAX4236 toc16
MINIMUM OUTPUT VOLTAGE (mV)
3.5
SUPPLY VOLTAGE (V)
VCC = 5V, RL = 1kΩ
35
3.0
TEMPERATURE (°C)
45
40
2.5
MAX4236 toc18
-25
50
8
7
6
5
4
3
2
1
0
0
0
3.0
3.5
4.0
4.5
SUPPLY VOLTAGE (V)
8
60
315
-50
MAX4236 toc21
300
OUTPUT VOLTAGE (mV)
MAX4236/MAX4237
SOT23, Very High Precision, 3V/5V
Rail-To-Rail Op Amps
5.0
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
OUTPUT VOLTAGE (V)
0
0.5
1.0
1.5
2.0
OUTPUT VOLTAGE (V)
_______________________________________________________________________________________
2.5
3.0
SOT23, Very High Precision, 3V/5V
Rail-To-Rail Op Amps
OUTPUT SINK CURRENT
vs. OUTPUT VOLTAGE
60
50
40
30
20
50
40
30
20
10
20
MAX4236 toc24
VCC = 3V
OUTPUT TO GND
SHORT-CIRCUIT CURRENT (mA)
15
VCC = 5V
10
VCC = 3V
5
SHORTED TO VEE
(SOURCING CURRENT)
10
0
0
1.0
1.5
2.0
2.5
3.0
-25
0
25
50
75
TEMPERATURE (°C)
SHORT-CIRCUIT CURRENT
vs. TEMPERATURE
DC I/O TRANSFER CURVE
(RLOAD = 100kΩ)
DC I/O TRANSFER CURVE
(RLOAD = 1kΩ)
2.5
MAX4236 toc25
20
15
10
SHORTED TO VCC
(SINKING CURRENT)
1.5
1.0
0.5
0
-0.5
-1.0
-25
0
25
75
50
TEMPERATURE (°C)
100
125
2.0
125
VSUPPLY = ±2.5V
1.0
0.5
0
-0.5
-1.0
-1.5
-2.0
-2.0
-2.5
-100
-50
0
50
100
-100
DIFFERENTIAL INPUT VOLTAGE (µV)
-50
0
50
100
DIFFERENTIAL INPUT VOLTAGE (µV)
MAX4237
NONINVERTING SMALL-SIGNAL RESPONSE
MAX4236
NONINVERTING SMALL-SIGNAL RESPONSE
MAX4236 toc28
MAX4236 toc29
0
INPUT
10mV/div
0
0
OUTPUT
10mV/div
0
INPUT
10mV/div
OUTPUT
50mV/div
1µs/div
1µs/div
VCC = ±2.5V
RL = 1kΩ, CL = 15pF
AV = 1V/V
100
1.5
-1.5
-2.5
0
2.5
OUTPUT VOLTAGE (V)
VCC = 5V
25
VSUPPLY = ±2.5V
2.0
OUTPUT VOLTAGE (V)
VCC = 3V
30
-50
-50
OUTPUT VOLTAGE (V)
35
SHORT-CIRCUIT CURRENT (mA)
0.5
OUTPUT VOLTAGE (V)
40
5
0
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
MAX4236 toc26
0
MAX4236 toc27
OUTPUT SINK CURRENT (mA)
70
60
SHORT-CIRCUIT CURRENT
vs. TEMPERATURE
MAX4236 toc23
VCC = 5V
OUTPUT TO GND
OUTPUT SINK CURRENT (mA)
80
MAX4236 toc22
OUTPUT SINK CURRENT
vs. OUTPUT VOLTAGE
VCC = ±2.5V
RL = 1kΩ, CL = 15pF
AV = 5V/V
_______________________________________________________________________________________
9
MAX4236/MAX4237
Typical Operating Characteristics (continued)
(VCC = +5V, VEE = 0, VCM = VCC/2, RL = 100kΩ to VCC/2, TA = +25°C, unless otherwise noted.)
MAX4236/MAX4237
SOT23, Very High Precision, 3V/5V
Rail-To-Rail Op Amps
Typical Operating Characteristics (continued)
(VCC = +5V, VEE = 0, VCM = VCC/2, RL = 100kΩ to VCC/2, TA = +25°C, unless otherwise noted.)
MAX4237
NONINVERTING LARGE-SIGNAL RESPONSE
MAX4237
NONINVERTING LARGE-SIGNAL RESPONSE
MAX4236 toc30
MAX4236 toc31
INPUT
200mV/div
0
0
OUTPUT
1V/div
INPUT
200mV/div
0
0
2µs/div
OUTPUT
1V/div
1µs/div
VCC = ±2.5V
RL = 100kΩ, CL = 15pF
AV = 5V/V
VCC = ±2.5V
RL = 1kΩ, CL = 15pF
AV = 5V/V
MAX4236
NONINVERTING LARGE-SIGNAL RESPONSE
MAX4236
NONINVERTING LARGE-SIGNAL RESPONSE
MAX4236 toc32
MAX4236 toc33
INPUT
1V/div
INPUT
1V/div
0
0
OUTPUT
1V/div
0
0
4µs/div
VCC = ±2.5V
RL = 1kΩ, CL = 15pF
AV = 1V/V
10
OUTPUT
1V/div
4µs/div
VCC = ±2.5V
RL = 100kΩ, CL = 15pF
AV = 1V/V
______________________________________________________________________________________
SOT23, Very High Precision, 3V/5V
Rail-To-Rail Op Amps
NAME
PIN
SOT23
SO/µMAX
1
6
FUNCTION
OUT
Amplifier Output
Negative Power Supply. Bypass with a 0.1µF capacitor to ground. Connect to GND
for single-supply operation.
2
4
VEE
3
3
IN+
Noninverting Amplifier Input
4
2
IN-
Inverting Amplifier Input
5
8
SHDN
Shutdown Input. Do not leave floating. Connect to VCC for normal operation or GND
to enter the shutdown mode.
6
7
VCC
Positive Supply Input. Bypass with a 0.1µF capacitor to ground.
—
1, 5
N.C.
No Connection. Not internally connected.
Detailed Description
The MAX4236/MAX4237 are high-precision op amps
with a CMOS input stage and an excellent set of DC
and AC features. The combination of tight maximum
voltage offset, low offset tempco and very low input
current make them ideal for use in high-precision DC
circuits. They feature low-voltage operation, low-power
consumption, high-current drive with rail-to-rail output
swing and high-gain bandwidth product.
High Accuracy
The MAX4236/MAX4237 maximum input offset voltage
is 20µV (5µV, typ) for grade A version and 50µV for
grade B version at +25°C. The maximum temperature
coefficient of the offset voltage for grade A and B are
guaranteed to be 2µV/°C and 4.5µV/°C respectively.
The parts have an input bias current of 1pA. Noise
characteristics are 14nV/√Hz, and a low frequency
noise (0.1Hz to 10Hz) of 0.2µVp-p. The CMRR is
102dB, and the PSRR is 120dB. The combination is
what is necessary for the design of circuits to process
signals while keeping high signal-to-noise ratios, as in
stages preceding high-resolution converters, or when
they are produced by sensors or transducers generating very small outputs.
Rail-to-Rail Outputs, Ground-Sensing Input
The input common-mode range extends from (VEE 0.15V) to (VCC - 1.2V) with excellent common-mode
rejection. Beyond this range, the amplifier output is a
nonlinear function of the input, but does not undergo
phase reversal or latch-up (see Typical Operating
Characteristics).
The output swings to within 150mV of the power-supply
rails with a 1kΩ load. The input ground sensing and the
rail-to-rail output substantially increase the dynamic
range.
Power-Up and Shutdown Mode
The MAX4236/MAX4237 have a shutdown option.
When the shutdown pin (SHDN) is pulled low, the supply current drops to 0.1µA, and the amplifiers are disabled with the output in a high-impedance state. Pulling
SHDN high enables the amplifiers. The turn-on time for
the amplifiers to come out of shutdown is 4µs.
Applications Information
As described above, the characteristics of the
MAX4236/MAX4237 are excellent for high-precision/
accuracy circuitry, and the high impedance, low-current, low-offset, and noise specifications are very
attractive for piezoelectric transducers applications. In
these applications, the sensors generate an amount of
electric charge proportional to the changes in the
mechanical stress applied to them. These charges are
transformed into a voltage proportional to the applied
force by injecting them into a capacitance and then
amplifying the resulting voltage. The voltage is an
inverse function of the capacitance into which the
charges generated by the transducer/ sensor are
injected. This capacitance and the resistance that discharges it, define the low-frequency response of the
circuit. It is desirable, once the preferred low-frequency
response is known, to maintain the capacitance as low
as possible, because the amount of necessary
upstream amplification (and the signal-to-noise ratio
deterioration) is directly proportional to the capacitance
value. The MAX4236/MAX4237 high-impedance, low-
______________________________________________________________________________________
11
MAX4236/MAX4237
Pin Description
MAX4236/MAX4237
SOT23, Very High Precision, 3V/5V
Rail-To-Rail Op Amps
Selector Guide
current, low-noise inputs allow a minimum of capacitance to be used.
Piezoresistive transducers applications require many of
the same qualities. For those applications the
MAX4236/MAX4237 high CMRR, PSRR, and offset stability are also a good match.
A typical application for a piezoresistive transducer
instrumentation amplifier design using the
MAX4236/MAX4237 is shown in the Typical Application
Circuit.
In general, the MAX4236/MAX4237 are good components for any application in which an amplifier with an
almost zero input current is required, including highprecision, long time-constant integrators and electrochemical sensors.
Power Supplies
The MAX4236/MAX4237 can operate from a single
+2.4V to +5.5V power supply, or from ±1.2V to ±2.75V
power supplies. The power supply pin(s) must be
bypassed to ground with a 0.1µF capacitor as close to
the pin as possible.
GRADE
MINIMUM
STABLE
GAIN
TOP MARK
MAX4236EUT
—
1
AAUV
MAX4236AEUA
A
1
—
MAX4236BEUA
B
1
—
MAX4236AESA
A
1
—
PART
MAX4236BESA
B
1
—
MAX4237EUT
—
5
AAUW
MAX4237AEUA
A
5
—
MAX4237BEUA
B
5
—
MAX4237AESA
A
5
—
MAX4237BESA
B
5
—
Typical Application Circuit
Layout and Physical Design
A good layout improves performance by decreasing
the amount of parasitic and stray capacitance, inductance and resistance at the amplifier’s inputs, outputs,
and power-supply connections. Since parasitics might
be unavoidable, minimize trace lengths, resistor leads,
and place external components as close to the pins as
possible.
In high impedance, low input current applications, input
lines guarding and shielding, special grounding, and
other physical design and layout techniques, are
mandatory if good results are expected.
The negative effects of crosstalk, EMI and other forms
of interference and noise (thermal, acoustic, etc.) must
be accounted for and prevented beforehand for good
performance in the type of sensitive circuitry in which
the MAX4236/MAX4237 are likely to be used.
+VS
VOUT
MAX4236
-VS
+VS
LOAD CELL
MAX4236
-VS
Chip Information
TRANSISTOR COUNTS: 224
PROCESS: BiCMOS
12
______________________________________________________________________________________
SOT23, Very High Precision, 3V/5V
Rail-To-Rail Op Amps
6LSOT.EPS
8LUMAXD.EPS
______________________________________________________________________________________
13
MAX4236/MAX4237
Package Information
SOT23, Very High Precision, 3V/5V
Rail-To-Rail Op Amps
SOICN.EPS
MAX4236/MAX4237
Package Information (continued)
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
14 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2001 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
工商网监
湘ICP备2023018690号
