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MAX4249–MAX4257
UCSP, Single-Supply, Low-Noise,
Low-Distortion, Rail-to-Rail Op Amps
General Description
Features
The MAX4249–MAX4257 low-noise, low-distortion operational amplifiers offer rail-to-rail outputs and single-supply
operation down to 2.4V. They draw 400μA of quiescent
supply current per amplifier while featuring ultra-low
distortion (0.0002% THD), as well as low input voltagenoise density (7.9nV/√Hz) and low input current-noise
density (0.5fA/√Hz). These features make the devices an
ideal choice for portable/battery-powered applications that
require low distortion and/or low noise.
For additional power conservation, the MAX4249/
MAX4251/MAX4253/MAX4256 offer a low-power shutdown mode that reduces supply current to 0.5μA and puts
the amplifiers’ outputs into a high-impedance state. The
MAX4249-MAX4257’s outputs swing rail-to-rail and their
input common-mode voltage range includes ground. The
MAX4250–MAX4254 are unity-gain stable with a gainbandwidth product of 3MHz. The MAX4249/MAX4255/
MAX4256/MAX4257 are internally compensated for gains
of 10V/V or greater with a gain-bandwidth product of
22MHz. The single MAX4250/MAX4255 are available in
space-saving 5-pin SOT23 packages. The MAX4252 is
available in an 8-bump chip-scale package (UCSP™)
and the MAX4253 is available in a 10-bump UCSP. The
MAX4250AAUK comes in a 5-pin SOT23 package and
is specified for operation over the automotive (-40°C to
+125°C) temperature range.
● Available in Space-Saving UCSP, SOT23, and
µMAX® Packages
● Low Distortion: 0.0002% THD (1kΩ load)
● 400µA Quiescent Supply Current per Amplifier
● Single-Supply Operation from 2.4V to 5.5V
● Input Common-Mode Voltage Range Includes
Ground
● Outputs Swing Within 8mV of Rails with a 10kΩ Load
● 3MHz GBW Product, Unity-Gain Stable
(MAX4250–MAX4254)
• 22MHz GBW Product, Stable with AV ≥ 10V/V
(MAX4249/MAX4255/MAX4256/MAX4257)
● Excellent DC Characteristics
• VOS = 70µV
• IBIAS = 1pA
• Large-Signal Voltage Gain = 116dB
● Low-Power Shutdown Mode
• Reduces Supply Current to 0.5µA
• Places Outputs in a High-Impedance State
● 400pF Capacitive-Load Handling Capability
Ordering Information
PART
Applications
●
●
●
●
●
●
Wireless Communications Devices
PA Control
Portable/Battery-Powered Equipment
Medical Instrumentation
ADC Buffers
Digital Scales/Strain Gauges
TEMP RANGE
PINPACKAGE
TOP
MARK
MAX4249ESD+
-40°C to +85°C
14 SO
—
MAX4249EUB+
-40°C to +85°C
10 µMAX
—
MAX4250EUK+T
-40°C to +85°C
5 SOT23
ACCI
MAX4250AAUK+T
-40°C to +125°C 5 SOT23
AEYJ
+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
Ordering Information continued at end of data sheet.
Selector Guide appears at end of data sheet.
Pin/Bump Configurations
TOP VIEW
(BUMPS ON BOTTOM)
1
2
A
OUTA
VDD
B
INA-
3
A1
A2
A3
A4
OUTB
OUTB
INB-
INB+
SHDNB
INB-
VDD
C1
C2
C3
C4
INB+
OUTA
INA-
INA+
SHDNA
B4
B1
C
INA+
MAX4252
VSS
UCSP
MAX4253
VSS
UCSP
Pin/Bump Configurations continued at end of data sheet.
UCSP is a trademark and μMAX is a registered trademark of Maxim Integrated Products, Inc.
19-1295; Rev 10; 4/20
© 2021 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners.
One Analog Way, Wilmington, MA 01887 U.S.A.
|
Tel: 781.329.4700
|
© 2021 Analog Devices, Inc. All rights reserved.
MAX4249–MAX4257
UCSP, Single-Supply, Low-Noise,
Low-Distortion, Rail-to-Rail Op Amps
Absolute Maximum Ratings
Power-Supply Voltage (VDD to VSS).....................+6.0V to -0.3V
Analog Input Voltage (IN_+, IN_-).. (VDD + 0.3V) to (VSS - 0.3V)
SHDN Input Voltage.....................................6.0V to (VSS - 0.3V)
Output Short-Circuit Duration to Either Supply ..........Continuous
Continuous Power Dissipation (TA = +70°C)
5-Pin SOT23 (derate 7.1mW/°C above +70°C)...........571mW
8-Bump UCSP (derate 4.7mW/°C above +70°C).........379mW
8-Pin μMAX (derate 4.5mW/°C above +70°C).............362mW
8-Pin SO (derate 5.88mW/°C above +70°C)................471mW
10-Bump UCSP (derate 6.1mW/°C above +70°C).......484mW
10-Pin μMAX (derate 5.6mW/°C above +70°C)...........444mW
14-Pin SO (derate 8.33mW/°C above +70°C)..............667mW
Operating Temperature Range............................ -40°C to +85°C
MAX4250AAUK............................................. -40°C to +125°C
Junction Temperature.......................................................+150°C
Storage Temperature Range............................. -65°C to +150°C
Lead Temperature (soldering, 10s).................................. +300°C
Soldering Temperature (reflow)........................................+260°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
(VDD = 5V, VSS = 0V, VCM = 0V, VOUT = VDD/2, RL connected to VDD/2, SHDN = VDD, TA = TMIN to TMAX, unless otherwise noted.
Typical values are at TA = +25°C.) (Notes 2, 3)
PARAMETER
Supply Voltage Range
SYMBOL
VDD
CONDITIONS
(Note 4)
MIN
2.4
VDD = 3V
Quiescent Supply Current
Per Amplifier
IQ
Normal
mode
VDD = 5V
E temperature
420
MAX4250AAUK
Input Offset Voltage Tempco
TCVOS
E temperature
IB
Differential Input Resistance
Input Common-Mode Voltage
Range
Common-Mode Rejection
Ratio
www.analog.com
IOS
CMRR
575
0.5
1.5
±0.75
(Note 6)
0.1
(Note 6)
µV/°C
50
TA = -40°C to +125°C
1500
10
TA = -40°C to +125°C
100
1000
Guaranteed by
CMRR test
MAX4250AAUK
0
VSS - 0.2V ≤ VCM ≤
VDD - 1.1V
E temperature
70
MAX4250AAUK
68
pA
GΩ
-0.2
VDD -1.1
VDD -1.1
115
pA
1
TA = -40°C to +85°C
E temperature
mV
1
TA = -40°C to +85°C
0.1
µA
655
0.3
RIN
VCM
V
±1.85
TA = +25°C
Input Offset Current
5.5
±0.07
MAX4250AAUK
TA = +25°C
Input Bias Current
UNITS
675
420
Shutdown mode (SHDN = VSS) (Note 2)
VOS
MAX
400
VDD = 5V, UCSP only
Input Offset Voltage (Note 5)
TYP
V
dB
Analog Devices │ 2
MAX4249–MAX4257
UCSP, Single-Supply, Low-Noise,
Low-Distortion, Rail-to-Rail Op Amps
Electrical Characteristics (continued)
(VDD = 5V, VSS = 0V, VCM = 0V, VOUT = VDD/2, RL connected to VDD/2, SHDN = VDD, TA = TMIN to TMAX, unless otherwise noted.
Typical values are at TA = +25°C.) (Notes 2, 3)
PARAMETER
Power-Supply Rejection Ratio
Large-Signal Voltage Gain
Output Voltage Swing
Output Voltage Swing
Output Short-Circuit Current
Output Leakage Current
SYMBOL
PSRR
AV
VOUT
VOUT
CONDITIONS
MIN
TYP
E temperature
75
100
MAX4250AAUK
72
RL = 10kΩ to VDD/2;
VOUT = 25mV to VDD
– 4.97V
E temperature
80
MAX4250AAUK
77
RL = 1kΩ to VDD/2;
VOUT = 150mV to
VDD – 4.75V
E temperature
80
MAX4250AAUK
77
VDD – 2.4V to 5.5V
|VIN+ - VIN-| ≥ 10mV;
RL = 10kΩ to VDD/2
|VIN+ - VIN-| ≥ 10mV,
RL = 1kΩ to VDD/2
VOL - VSS
VDD - VOH
VOL - VSS
E
ILEAK
VIL
(Note 2)
(Note 2)
Slew Rate
Peak-to-Peak Input-Noise
Voltage
Input Voltage-Noise Density
Input Current-Noise Density
www.analog.com
7
A
77
A
47
A
SHDN = VSS = VDD (Note 2)
enP-P
en
in
mV
200
225
E
100
mV
125
0.001
mA
1.0
0.2 x VDD
0.8 x VDD
µA
V
V
0.5
11
SR
20
25
E
Input Capacitance
GBW
25
30
Shutdown mode (SHDN = VSS),
VOUT = VSS to VDD (Note 2)
VIH
Gain-Bandwidth Product
dB
68
SHDN Logic High
IIL/IIH
dB
112
8
E
UNITS
116
A
ISC
SHDN Logic Low
SHDN Input Current
VDD - VOH
MAX
MAX4250–MAX4254
3
MAX4249/MAX4255/MAX4256/MAX4257
22
MAX4250–MAX4254
0.3
MAX4249/MAX4255/MAX4256/MAX4257
2.1
f = 0.1Hz to 10Hz
760
f = 10Hz
27
f = 1kHz
8.9
f = 30kHz
7.9
f = 1kHz
0.5
1.5
µA
pF
MHz
V/µs
nVP-P
nV/√Hz
fA/√Hz
Analog Devices │ 3
MAX4249–MAX4257
UCSP, Single-Supply, Low-Noise,
Low-Distortion, Rail-to-Rail Op Amps
Electrical Characteristics (continued)
(VDD = 5V, VSS = 0V, VCM = 0V, VOUT = VDD/2, RL connected to VDD/2, SHDN = VDD, TA = TMIN to TMAX, unless otherwise noted.
Typical values are at TA = +25°C.) (Notes 2, 3)
PARAMETER
Total Harmonic Distortion
Plus Noise
SYMBOL
THD+N
Capacitive-Load Stability
Gain Margin
GM
Phase Margin
ΦM
CONDITIONS
TYP
MAX4250–MAX4254
AV = 1V/V, VOUT = 2VP-P,
RL = 1kΩ to GND
(Note 7)
f = 1kHz
0.0004
f = 20kHz
0.006
MAX4249/MAX4255/
MAX4256/MAX4257
AV = 1V/V, VOUT = 2VP-P,
RL = 1kΩ to GND (Note 7)
f = 1kHz
0.0012
f = 20kHz
0.007
No sustained oscillations
400
MAX4250–MAX4254, AV = 1V/V
10
MAX4249/MAX4255/MAX4256/MAX4257,
AV = 10V/V
74
MAX4249/MAX4255/MAX4256/MAX4257,
AV = 10V/V
68
MAX4250–MAX4254
6.7
MAX4249/MAX4255/
MAX4256/MAX4257
1.6
MAX4251/MAX4253
0.8
Delay Time to Shutdown
tSH
IVDD = 5% of
normal operation
MAX4249/MAX4256
1.2
Delay Time to Enable
tEN
VOUT = 2.5V, VOUT MAX4251/MAX4253
settles to 0.1%
MAX4249/MAX4256
3.5
Power-Up Delay Time
tPU
VDD = 0 to 5V step, VOUT stable to 0.1%
Note
Note
Note
Note
Note
Note
MAX
UNITS
%
pF
dB
12.5
MAX4250–MAX4254, AV = 1V/V
To 0.01%, VOUT =
2V step
Settling Time
MIN
Degrees
µs
µs
8
µs
6
µs
2: SHDN is available on the MAX4249/MAX4251/MAX4253/MAX4256 only.
3: All device specifications are 100% tested at TA = +25°C. Limits over temperature are guaranteed by design.
4: Guaranteed by the PSRR test.
5: Offset voltage prior to reflow on the UCSP.
6: Guaranteed by design.
7: Lowpass-filter bandwidth is 22kHz for f = 1kHz and 80kHz for f = 20kHz. Noise floor of test equipment = 10nV/√Hz.
www.analog.com
Analog Devices │ 4
MAX4249–MAX4257
UCSP, Single-Supply, Low-Noise,
Low-Distortion, Rail-to-Rail Op Amps
Typical Operating Characteristics
(VDD = 5V, VSS = 0V, VCM = VOUT = VDD/2, input noise floor of test equipment =10nV/√Hz for all distortion measurements,
TA = +25°C, unless otherwise noted.)
25
20
100
-100
-150
5
100
VDD = 3V
50
VDD = 5V
0
-20
0
20
40
60
OUTPUT VOLTAGE
vs. OUTPUT LOAD CURRENT
OUTPUT VOLTAGE SWING (VOH)
vs. TEMPERATURE
VOL
0.2
RL = 1kΩ
0.07
0.05
0.04
4
5
6
7
8
9
0
10
-40
OUTPUT LOAD CURRENT (mA)
120
RL = 20kΩ
110
0
20
40
60
0
80
90
130
120
110
RL = 20kΩ
RL = 2kΩ
80
70
VDD = 3V
RL REFERENCED TO GND
0
50
100
150
200
-20
250
60
0
20
40
60
80
LARGE-SIGNAL VOLTAGE GAIN
vs. OUTPUT VOLTAGE SWING
RL = 200kΩ
130
120
110
RL = 20kΩ
100
RL = 2kΩ
90
80
70
70
VOUT SWING FROM EITHER SUPPLY (mV)
www.analog.com
-40
140
RL = 200kΩ
100
90
80
60
RL = 10kΩ
RL = 100kΩ
TEMPERATURE (°C)
LARGE-SIGNAL VOLTAGE GAIN
vs. OUTPUT VOLTAGE SWING
140
AV (dB)
RL = 2kΩ
100
-20
MAX4249-57 TOC08
RL = 200kΩ
MAX4249-57 TOC07
130
0.03
TEMPERATURE (°C)
LARGE-SIGNAL VOLTAGE GAIN
vs. OUTPUT VOLTAGE SWING
140
RL = 1kΩ
0.01
RL = 10kΩ
RL = 100kΩ
AV (dB)
3
4.5
0.02
0.01
2
3.5
0.04
0.06
0.02
1
2.5
0.05
0.03
0
1.5
OUTPUT VOLTAGE SWING (VOL)
vs. TEMPERATURE
0.06
VOL (V)
VDD - VOH (V)
0.4
0.09
0.08
0.5
INPUT COMMON-MODE VOLTAGE (V)
MAX4249-57 TOC05
MAX4249-57 TOC04
VDD - VOH
0.3
0.10
-50
-0.5
80
MAX4249 -57TOC06
-40
TEMPERATURE (°C)
0.1
AV (dB)
150
MAX4249-57 TOC09
-95
-75
-55
-35
-13
7
28
49
69
90
110
131
152
172
192
-250
VOS (µV)
VDD = 3V OR 5V
VDIFF = ±10mV
0.5
50
200
-200
0.6
OUTPUT VOLTAGE (V)
0
-50
10
0
50
INPUT OFFSET VOLTAGE
vs. INPUT COMMON-MODE VOLTAGE
MAX4249-57 TOC03
150
15
0
VCM = 0
200
INPUT OFFSET VOLTAGE (µV)
30
250
VOS (µV)
NUMBER OF UNITS
35
OFFSET VOLTAGE
vs. TEMPERATURE
MAX4249-57 TOC02
400 UNITS
VCM = 0
TA = +25°C
MAX4249-57 TOC01
40
MAX4251/MAX4256
INPUT OFFSET VOLTAGE DISTRIBUTION
VDD = 3V
RL REFERENCED TO GND
0
50
100
150
200
250
VOUT SWING FROM EITHER SUPPLY (mV)
VDD = 5V
RL REFERENCED TO GND
60
50
0
50
100
150
200
250
VOUT SWING FROM EITHER SUPPLY (mV)
Analog Devices │ 5
MAX4249–MAX4257
UCSP, Single-Supply, Low-Noise,
Low-Distortion, Rail-to-Rail Op Amps
Typical Operating Characteristics (continued)
(VDD = 5V, VSS = 0V, VCM = VOUT = VDD/2, input noise floor of test equipment =10nV/√Hz for all distortion measurements,
TA = +25°C, unless otherwise noted.)
RL = 100kΩ
VOUT = 10mV
TO 4.99mV
110
80
105
VDD = 5V
RL REFERENCED TO GND
SUPPLY CURRENT AND SHUTDOWN
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX4249-57 TOC13
440
PER AMPLIFIER
420
SUPPLY CURRENT (µA)
100
50
100
150
200
250
VOUT SWING FROM EITHER SUPPLY (mV)
0.6
0.5
SHDN = VDD
400
0.4
SHDN = VSS
380
0.3
360
0.2
340
0.1
320
0
1.8
2.3
2.8
3.3
3.8
4.3
4.8
5.3 5.5
-40
-20
2000
GAIN
20
40
72
30
-36
-10
-72
PHASE
60
108
36
-108
0.01
0.1
1
40
GAIN
180
0
144
-10
108
RL = 100kΩ
1.8
2.3
72
20
36
10
0
0
-36
PHASE
-10
4.3
4.8
5.3
-72
VDD = 3V, 5V
-60
PSRR+
-70
-80
-30
-144
-100
-180
10M
-110
1M
MAX4250–MAX4254
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
-50
-90
FREQUENCY (Hz)
3.8
-40
-108
100k
3.3
-30
-20
10k
2.8
-20
-40
www.analog.com
RL = 1kΩ
SUPPLY VOLTAGE (V)
-180
10M
FREQUENCY (Hz)
0.373
RL = 10kΩ
100
5
MAX4249-57 TOC17
VDD = 3V, 5V
RL = 50kΩ
CL = 20pF
AV = 1000
1k
80
80
MAX4249/MAX4255/MAX4256/MAX4257
GAIN AND PHASE vs. FREQUENCY
100
60
VCM = 0
VOUT = VDD/2
RL REFERENCED TO GND
120
-144
1M
40
140
-40
100k
20
INPUT OFFSET VOLTAGE
vs. SUPPLY VOLTAGE
160
-30
10k
0
60
50
0
1k
-20
180
VDD = 3V
144
0
100
-40
TEMPERATURE (°C)
400
180
10
-20
340
80
VDD = 5V
GAIN (dB)
GAIN (dB)
30
60
1000
100
0.001
PHASE (DEGREES)
MAX4249-57 TOC16
VDD = 3V, 5V
RL = 50kΩ
CL = 20pF
AV = 1000
40
40
OUTPUT VOLTAGE (V)
MAX4250–MAX4254
GAIN AND PHASE vs. FREQUENCY
50
20
360
SUPPLY CURRENT
vs. OUTPUT VOLTAGE
SUPPLY VOLTAGE (V)
60
0
0.374
SHDN = VSS
TEMPERATURE (°C)
SUPPLY CURRENT (µA)
0
SHUTDOWN SUPPLY CURRENT (µA)
50
RL = 10kΩ
VOUT = 20mV
TO 4.975mV
RL = 1kΩ
VOUT = 150mV
TO 4.75mV
SHDN = VDD
380
PSRR (dB)
60
400
MAX4249-57 TOC14
70
0.375
420
PSRR-
1
10
100
1k
10k
100k
1M
10M
FREQUENCY (Hz)
Analog Devices │ 6
SHUTDOWN SUPPLY CURRENT (µA)
90
0.376
MAX4249-57 TOC15
100
115
MAX4249-57 TOC12
PER AMPLIFIER
440
PHASE (DEGREES)
110
RL REFERENCED TO VDD/2
VDD = 5V
SUPPLY CURRENT AND SHUTDOWN
SUPPLY CURRENT vs. TEMPERATURE
MAX4249-57 TOC18
RL = 2kΩ
AV (dB)
AV (dB)
120
120
SUPPLY CURRENT (µA)
RL = 20kΩ
130
460
VOS (µV)
RL = 200kΩ
140
125
MAX4249-57 TOC10
150
LARGE-SIGNAL VOLTAGE GAIN
vs. TEMPERATURE
MAX4249-57 TOC11
LARGE-SIGNAL VOLTAGE GAIN
vs. OUTPUT VOLTAGE SWING
MAX4249–MAX4257
UCSP, Single-Supply, Low-Noise,
Low-Distortion, Rail-to-Rail Op Amps
Typical Operating Characteristics (continued)
1
AV = 1 (MAX4250–MAX4254)
0.1
100k
1M
10M
10
5
VP-PNOISE = 760nVP-P
0
10
100
MAX4250–MAX4254
FFT OF DISTORTION AND NOISE
-40
-60
fO
-80
-100
HD2 HD4
-120
HD3
0
VIN
-20
-40
fO
-60
10kΩ
100kΩ
-80
HD2
10
AV = 10
VIN
fO = 3kHz
FILTER BW = 30kHz
1
VO
0.1
RL = 1kΩ
0.01
HD3
RL = 10kΩ
5k
10k
15k
-140
20k
10
5k
VIN
1
0.1
VOUT
RL
100kΩ
RL = 1kΩ
AV = 10
fO = 3kHz
FILTER BW = 30kHz
0
1
2
VIN
AV = 10
11kΩ
0.1
VOUT
RL
100kΩ
fO = 20kHz, FILTER BW = 80kHz
1
2
3
0.001
1
1
2
3
4
VIN
RL
0.1
5
4
OUTPUT VOLTAGE (VP-P)
5
AV = 100
R1 = 560Ω, R2 = 53kΩ
0.01
R1 = 5.6kΩ, R2 = 53kΩ
0.0001
10
VOUT
R2
R1
AV = 10
FILTER BW = 22kHz
RL = 10kΩ TO GND
VO = 2VP-P
AV = 1
fO = 3kHz, FILTER BW = 30kHz
0
3
MAX4250–MAX4254
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
0.001
RL = 100kΩ
OUTPUT VOLTAGE (VP-P)
www.analog.com
1
0.01
RL = 10kΩ
0.01
RL = 100kΩ
0
OUTPUT VOLTAGE (VP-P)
MAX4249/MAX4255/MAX4256/MAX4257
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT VOLTAGE SWING
THD+N (%)
11kΩ
0.001
20k
FREQUENCY (Hz)
MAX4249-57 TOC25
10
15k
10k
THD+N (%)
10
RL
100kΩ
11kΩ
-120
MAX4250–MAX4254
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT VOLTAGE SWING (VDD = 3V)
THD+N (%)
MAX4250–MAX4254
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT VOLTAGE (VDD = 5V)
VO
11kΩ
FREQUENCY (Hz)
0.001
1s/div
100k
VOUT = 4VP-P
fO = 1kHz
-100
HD5
-140
-160
10k
MAX4249/MAX4255/MAX4256/MAX4257
FFT OF DISTORTION AND NOISE
20
AMPLITUDE (dBc)
AMPLITUDE (dBc)
-20
RL = 1kΩ
fO = 1kHz
AV = 1
MAX4249-57 TOC22
VOUT = 2VP-P
1k
FREQUENCY (Hz)
FREQUENCY (Hz)
0
MAX4249-57 TOC21
200nV/div
15
THD+N (%)
10k
20
MAX4249-57 TOC23
1k
25
VDD = 3V OR 5V
MAX4249-57 TOC24
10
0.1Hz TO 10HzP-P NOISE
MAX4249-57 TOC27
100
30
MAX4249-57 TOC20
AV = 10 (MAX4249/MAX4255/
MAX4256/MAX4257)
INPUT VOLTAGE-N0ISE DENSITY
vs. FREQUENCY
MAX4249-57 TOC26
OUTPUT IMPEDANCE (Ω)
1000
MAX4249-57 TOC19
OUTPUT IMPEDANCE
vs. FREQUENCY
Vn-EQUIVALENT INPUT NOISE-VOLTAGE (nV/√Hz)
(VDD = 5V, VSS = 0V, VCM = VOUT = VDD/2, input noise floor of test equipment =10nV/√Hz for all distortion measurements,
TA = +25°C, unless otherwise noted.)
100
1k
10k
FREQUENCY (Hz)
Analog Devices │ 7
MAX4249–MAX4257
UCSP, Single-Supply, Low-Noise,
Low-Distortion, Rail-to-Rail Op Amps
Typical Operating Characteristics (continued)
(VDD = 5V, VSS = 0V, VCM = VOUT = VDD/2, input noise floor of test equipment =10nV/√Hz for all distortion measurements,
TA = +25°C, unless otherwise noted.)
MAX4250–MAX4254
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
THD+N(%)
RL TO VDD/2
RL TO GND
VOUT
200mV/div
RL TO VDD
0.5V
0.001
0.0001
10
100
1k
10k
VDD = 3V
RL = 10kΩ
CL = 100pF
VIN = 1V PULSE
VDD = 3V
RL = 10kΩ
CL = 100pF
VIN = 100mV PULSE
AV = 10
2µs/div
MAX4249-57 TOC30
2µs/div
MAX4249-57 TOC32
MAX4249-57 TOC31
1.6V
VOUT
200mV/div
VDD = 3V
RL = 10kΩ
CL = 100pF
VIN = 100V PULSE
0.5V
MAX4249/MAX4255/MAX4256/MAX4257
SMALL-SIGNAL PULSE RESPONSE
MAX4249/MAX4255/MAX4256/MAX4257
LARGE-SIGNAL PULSE RESPONSE
1V
VOUT
20mV/div
2µs/div
FREQUENCY (Hz)
2V
0.6V
VOUT
50mV/div
1.5V
VDD = 3V
RL = 10kΩ
CL = 100pF
VIN = 10mV PULSE
AV = 10
2µs/div
140
CHANNEL SEPARATION vs. FREQUENCY
MAX4249-57 TOC33
0.01
1.5V
CHANNEL SEPARATION (dB)
FILTER BW = 80kHz
AV = 1
RL = 1kΩ
VOUT = 2VP-P
MAX4250–MAX4254
SMALL-SIGNAL PULSE RESPONSE
MAX4249-57 TOC29
MAX4249-57 TOC28
0.1
MAX4250–MAX4254
LARGE-SIGNAL PULSE RESPONSE
130
120
110
100
90
80
70
0
1k
10k
100k
1M
10M
FREQUENCY (Hz)
www.analog.com
Analog Devices │ 8
MAX4249–MAX4257
UCSP, Single-Supply, Low-Noise,
Low-Distortion, Rail-to-Rail Op Amps
Pin/Bump Description
PIN/BUMP
MAX4250/
MAX4255
MAX4251/
MAX4256
MAX4252/
MAX4252
MAX4257
MAX4249/
MAX4253
5-PIN
SOT23
8-PIN
SO/µMAX
8-PIN
SO/µMAX
8-BUMP
UCSP
10-BUMP
UCSP
10-PIN
µMAX
14-PIN
SO
1
6
1, 7
A1, A3
A1, C1
1, 9
1, 13
MAX4254
NAME
14-PIN
SO
OUT, OUTA,
1, 7, 8, 14 OUTB, OUTC, Amplifier Output
OUTD
2
4
4
C2
B4
4
4
11
VSS
3
3
3, 5
C1, C3
A3, C3
3, 7
3, 11
3, 5, 10,
12
IN+, INA+,
INB+, INC+,
IND+
4
2
2, 6
B1, B3
A2, C2
2, 8
2, 12
2, 6, 9, 13
5
7
8
A2
B1
10
14
4
VDD
8
—
—
A4, C4
5, 6
6, 9
—
SHDN,
SHDNA,
SHDNB
—
1, 5
—
—
—
—
5, 7,
8, 10
—
N.C.
—
—
—
B2
B2, B3
—
—
—
—
The MAX4249–MAX4257 single-supply operational
amplifiers feature ultra-low noise and distortion while
consuming very little power. Their low distortion and low
noise make them ideal for use as preamplifiers in wide
dynamic-range applications, such as 16-bit analog-todigital converters (see Typical Operating Circuit). Their
high-input impedance and low noise are also useful for
signal conditioning of high-impedance sources, such as
piezoelectric transducers.
These devices have true rail-to-rail output operation, drive
loads as low as 1kΩ while maintaining DC accuracy, and
can drive capacitive loads up to 400pF without oscillation.
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Negative Supply.
Connect to ground
for single-supply
operation
Noninverting
Amplifier Input
IN-, INA-, INB-, Inverting Amplifier
INC-, INDInput
—
Detailed Description
FUNCTION
Positive Supply
Shutdown Input,
Connect to
VDD or leave
unconnected for
normal operation
(amplifier(s)
enabled).
No Connection.
Not internally
connected.
Not populated with
solder sphere
The input common-mode voltage range extends from
VDD - 1.1V to 200mV beyond the negative rail. The pushpull output stage maintains excellent DC characteristics,
while delivering up to ±5mA of current.
The MAX4250–4254 are unity-gain stable, whereas, the
MAX4249/MAX4255/MAX4256/MAX4257 have a higher
slew rate and are stable for gains ≥ 10V/V. The MAX4249/
MAX4251/MAX4253/MAX4256 feature a low-power shutdown mode, which reduces the supply current to 0.5μA
and disables the outputs.
The MAX4250AAUK is specified for operation over the
automotive (-40°C to +125°C) temperature range.
Analog Devices │ 9
MAX4249–MAX4257
UCSP, Single-Supply, Low-Noise,
Low-Distortion, Rail-to-Rail Op Amps
Low Distortion
Many factors can affect the noise and distortion that the
device contributes to the input signal. The following guidelines offer valuable information on the impact of design
choices on Total Harmonic Distortion (THD).
Choosing proper feedback and gain resistor values for
a particular application can be a very important factor in
reducing THD. In general, the smaller the closedloop gain,
the smaller the THD generated, especially when driving
heavy resistive loads. Large-value feedback resistors can
significantly improve distortion. The THD of the part normally increases at approximately 20dB per decade, as a
function of frequency. Operating the device near or above
the full-power bandwidth significantly degrades distortion.
Referencing the load to either supply also improves the
part’s distortion performance, because only one of the
MOSFETs of the push-pull output stage drives the output.
Referencing the load to midsupply increases the part’s
distortion for a given load and feedback setting. (See
the Total Harmonic Distortion vs. Frequency graph in the
Typical Operating Characteristics.)
For gains ≥ 10V/V, the decompensated devices MAX4249/
MAX4255/MAX4256/MAX4257 deliver the best distortion
performance, since they have a higher slew rate and provide a higher amount of loop gain for a given closed-loop
gain setting. Capacitive loads below 400pF, do not significantly affect distortion results. Distortion performance
remains relatively constant over supply voltages.
Low Noise
The amplifier’s input-referred, noise-voltage density is
dominated by flicker noise at lower frequencies, and by
thermal noise at higher frequencies. Because the thermal
noise contribution is affected by the parallel combination
of the feedback resistive network (RF || RG, Figure 1),
these resistors should be reduced in cases where the
system bandwidth is large and thermal noise is dominant.
This noise contribution factor decreases, however, with
increasing gain settings.
For example, the input noise-voltage density of the circuit with RF = 100kΩ, RG = 11kΩ (AV = 10V/V) is en =
15nV/√Hz, en can be reduced to 9nV/√Hz by choosing
RF = 10kΩ, RG = 1.1kΩ (AV = 10V/V), at the expense of
greater current consumption and potentially higher distortion. For a gain of 100V/V with RF = 100kΩ, RG = 1.1kΩ,
the en is low (9nV/√Hz).
www.analog.com
CZ
RF
RG
VOUT
VIN
Figure 1. Adding Feed-Forward Compensation
AV = 2V/V
RF = RG = 10kΩ
VIN =
50mV/div
100mV
0
VOUT =
100mV/div
2µs/div
Figure 2a. Pulse Response with No Feed-Forward
Compensation
100mV
AV = 2
RF = RG = 100kΩ
CZ = 11pF
50mV/div
VIN
0
100mV/div
VOUT
2µs/div
Figure 2b. Pulse Response with 10pF Feed-Forward
Compensation
Analog Devices │ 10
MAX4249–MAX4257
UCSP, Single-Supply, Low-Noise,
Low-Distortion, Rail-to-Rail Op Amps
Using a Feed-Forward Compensation
Capacitor, CZ
RISO
CL
MAX4250
MAX4251
MAX4252
MAX4253
MAX4254
VIN
VOUT
The amplifier’s input capacitance is 11pF. If the resistance
seen by the inverting input is large (feedback network),
this can introduce a pole within the amplifier’s bandwidth, resulting in reduced phase margin. Compensate
the reduced phase margin by introducing a feed-forward
capacitor (CZ) between the inverting input and the output (Figure 1). This effectively cancels the pole from the
inverting input of the amplifier. Choose the value of CZ as
follows:
CZ = 11 x (RF / RG) [pF]
Figure 3. Overdriven Input Showing No Phase Reversal
4.25V
VOUT
0
4.45V
VIN
-200mV
0
AV = 1
VDD = 5V
RL = 10kΩ
Using a slightly smaller CZ than suggested by the formula
above achieves a higher bandwidth at the expense of
reduced phase and gain margin. As a general guideline,
consider using CZ for cases where RG || RF is greater
than 20kΩ (MAX4250–MAX4254) or greater than 5kΩ
(MAX4249/MAX4255/MAX4256/MAX4257).
Applications Information
The MAX4249–MAX4257 combine good driving capability
with ground-sensing input and rail-to-rail output operation. With their low distortion, low noise, and lowpower
consumption, these devices are ideal for use in portable
instrumentation systems and other low-power, noisesensitive applications.
20µs/div
Figure 4. Rail-to-Rail Output Operation
Ground-Sensing and Rail-to-Rail Outputs
5V
VOUT
1V/div
0
In the unity-gain stable MAX4250–MAX4254, the use of a
proper CZ is most important for AV = 2V/V, and AV = -1V/V.
In the decompensated MAX4249/MAX4255/MAX4256/
MAX4257, CZ is most important for AV = 10V/V. Figures 2a
and 2b show transient response both with and without CZ.
Figure 4 showcases the true rail-to-rail output operation
of the amplifier, configured with AV = 10V/V. The output
swings to within 8mV of the supplies with a 10kΩ load,
making the devices ideal in low-supply-voltage applications.
VDD = 5V
RL = 10kΩ
AV = 10
f = 1kHz
Output Loading and Stability
200µs/div
Figure 5. Capacitive-Load Driving Circuit
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The common-mode input range of these devices extends
below ground, and offers excellent commonmode rejection. These devices are guaranteed not to undergo phase
reversal when the input is overdriven (Figure 3).
Even with their low quiescent current of 400μA, these
amplifiers can drive 1kΩ loads while maintaining excellent DC accuracy. Stability while driving heavy capacitive
loads is another key feature.
Analog Devices │ 11
MAX4249–MAX4257
UCSP, Single-Supply, Low-Noise,
Low-Distortion, Rail-to-Rail Op Amps
4.5
140
4.0
RISO (Ω)
120
100
80
60
SHADED AREA INDICATES
STABLE OPERATION
WITH NO NEED FOR
ISOLATION RESISTOR.
40
20
0
10
100
1000
10,000
NOTE: USING AN ISOLATION RESISTOR REDUCES PEAKING.
Figure 6. Isolation Resistance vs. Capacitive Loading to
Minimize Peaking (
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