EVALUATION KIT AVAILABLE
MAX4249–MAX4257
UCSP, Single-Supply, Low-Noise,
Low-Distortion, Rail-to-Rail Op Amps
General Description
The MAX4249–MAX4257 low-noise, low-distortion operational amplifiers offer rail-to-rail outputs and singlesupply 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
voltage-noise 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-torail and their input common-mode voltage range
includes ground. The MAX4250–MAX4254 are unitygain stable with a gain-bandwidth 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 chipscale 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.
Applications
Wireless Communications Devices
PA Control
Portable/Battery-Powered Equipment
Medical Instrumentation
ADC Buffers
Digital Scales/Strain Gauges
Features
! Available in Space-Saving UCSP, SOT23, and
µMAX® Packages
! Low Distortion: 0.0002% THD (1k" 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 10k"
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
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
+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
—
AEYJ
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.
For pricing, delivery, and ordering information, please contact Maxim Direct at
1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
19-1295; Rev 9; 12/12
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
2
IOS
CMRR
575
655
0.5
1.5
±0.07
±0.75
0.3
(Note 6)
0.1
(Note 6)
TA = -40°C to +125°C
1500
10
TA = -40°C to +125°C
100
1000
Guaranteed by
CMRR test
VSS - 0.2V ≤ VCM ≤
VDD - 1.1V
pA
GΩ
-0.2
VDD -1.1
MAX4250AAUK
0
VDD -1.1
E temperature
70
MAX4250AAUK
68
115
pA
1
TA = -40°C to +85°C
E temperature
mV
1
50
0.1
µA
µV/°C
TA = -40°C to +85°C
RIN
VCM
V
±1.85
TA = +25°C
Input Offset Current
5.5
420
MAX4250AAUK
TA = +25°C
Input Bias Current
UNITS
675
Shutdown mode (SHDN = VSS) (Note 2)
VOS
MAX
400
VDD = 5V, UCSP only
Input Offset Voltage (Note 5)
TYP
V
dB
Maxim Integrated
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
VDD – 2.4V to 5.5V
RL = 10kΩ to VDD/2;
VOUT = 25mV to VDD
– 4.97V
RL = 1kΩ to VDD/2;
VOUT = 150V to VDD
– 4.75V
|VIN+ - VIN-| ≥ 10mV;
RL = 10kΩ to VDD/2
|VIN+ - VIN-| ≥ 10mV,
RL = 1kΩ to VDD/2
TYP
E temperature
75
100
MAX4250AAUK
72
E temperature
80
MAX4250AAUK
77
E temperature
80
MAX4250AAUK
77
VDD - VOH
VOL - VSS
VDD - VOH
VOL - VSS
E
A
E
ILEAK
SHDN Logic High
VIH
(Note 2)
A
Slew Rate
Peak-to-Peak Input-Noise
Voltage
Input Voltage-Noise Density
Input Current-Noise Density
Maxim Integrated
77
A
E
47
A
SHDN = VSS = VDD (Note 2)
SR
enP-P
en
in
mV
200
225
100
mV
125
0.001
mA
1.0
µA
0.2 X VDD
V
0.8 X VDD
V
0.5
11
GBW
25
30
20
25
E
Input Capacitance
Gain-Bandwidth Product
dB
112
7
Shutdown mode (SHDN = VSS),
VOUT = VSS to VDD (Note 2)
(Note 2)
UNITS
dB
68
VIL
IIL/IIH
MAX
116
8
ISC
SHDN Logic Low
SHDN Input Current
MIN
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
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
Phase Margin
GM
ΦM
CONDITIONS
MAX4250–MAX4254
AV = 1V/V, VOUT = 2VP-P,
RL = 1kΩ to GND
(Note 7)
MAX4249/MAX4255/
MAX4256/MAX4257
AV = 1V/V, VOUT = 2VP-P,
RL = 1kΩ to GND (Note 7)
0.0004
f = 20kHz
0.006
f = 1kHz
0.0012
f = 20kHz
0.007
10
MAX4249/MAX4255/MAX4256/MAX4257,
AV = 10V/V
74
MAX4249/MAX4255/MAX4256/MAX4257,
AV = 10V/V
68
Delay Time to Enable
tEN
VOUT = 2.5V,
VOUT settles to
0.1%
UNITS
MAX4250–MAX4254
6.7
MAX4249/MAX4255/
MAX4256/MAX4257
1.6
MAX4251/MAX4253
0.8
MAX4249/MAX4256
1.2
MAX4251/MAX4253
8
MAX4249/MAX4256
3.5
VDD = 0 to 5V step, VOUT stable to 0.1%
pF
dB
12.5
MAX4250–MAX4254, AV = 1V/V
IVDD = 5% of
normal
operation
MAX
%
MAX4250–MAX4254, AV = 1V/V
tSH
tPU
f = 1kHz
400
Delay Time to Shutdown
Power-Up Delay Time
TYP
No sustained oscillations
To 0.01%, VOUT
= 2V step
Settling Time
MIN
Degrees
µs
µs
µs
6
µs
Note 2: SHDN is available on the MAX4249/MAX4251/MAX4253/MAX4256 only.
Note 3: All device specifications are 100% tested at TA = +25°C. Limits over temperature are guaranteed by design.
Note 4: Guaranteed by the PSRR test.
Note 5: Offset voltage prior to reflow on the UCSP.
Note 6: Guaranteed by design.
Note 7: Lowpass-filter bandwidth is 22kHz for f = 1kHz and 80kHz for f = 20kHz. Noise floor of test equipment = 10nV/!Hz.
4
Maxim Integrated
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.)
100
50
0
-50
15
-100
10
-150
0
-250
-40
-20
VOS (µV)
OUTPUT VOLTAGE
vs. OUTPUT LOAD CURRENT
0.4
0.3
VOL
60
0.2
0.06
RL = 1kΩ
4
5
6
7
8
9
10
0.05
RL = 20kΩ
110
0.01
RL = 10kΩ
RL = 100kΩ
-40
-20
0
20
40
60
0
80
140
130
120
AV (dB)
100
90
110
RL = 20kΩ
RL = 200kΩ
100
RL = 2kΩ
80
70
VDD = 3V
RL REFERENCED TO GND
100
150
200
VOUT SWING FROM EITHER SUPPLY (mV)
Maxim Integrated
-20
250
60
0
20
40
60
80
LARGE-SIGNAL VOLTAGE GAIN
vs. OUTPUT VOLTAGE SWING
140
RL = 200kΩ
130
120
110
RL = 20kΩ
100
RL = 2kΩ
80
70
70
50
50
-40
90
90
80
0
RL = 10kΩ
RL = 100kΩ
TEMPERATURE (°C)
LARGE-SIGNAL VOLTAGE GAIN
vs. OUTPUT VOLTAGE SWING
RL = 2kΩ
60
0.03
0.02
MAX4249-57 TOC08
120
4.5
RL = 1kΩ
TEMPERATURE (°C)
MAX4249-57 TOC07
130
3.5
0.04
LARGE-SIGNAL VOLTAGE GAIN
vs. OUTPUT VOLTAGE SWING
RL = 200kΩ
2.5
0.04
0.06
OUTPUT LOAD CURRENT (mA)
140
1.5
0.05
AV (dB)
3
0.5
OUTPUT VOLTAGE SWING (VOL)
vs. TEMPERATURE
0.07
0
2
0
OUTPUT VOLTAGE SWING (VOH)
vs. TEMPERATURE
0.01
1
VDD = 5V
INPUT COMMON-MODE VOLTAGE (V)
0.02
0
VDD = 3V
50
-50
-0.5
80
0.03
0
100
TEMPERATURE (°C)
0.08
0.1
AV (dB)
40
0.09
VDD - VOH (V)
OUTPUT VOLTAGE (V)
VDD - VOH
20
VOL (V)
VDD = 3V OR 5V
VDIFF = ±10mV
0.5
0.10
MAX4249-57 TOC04
0.6
0
MAX4249-57 TOC05
-200
-95
-75
-55
-35
-13
7
28
49
69
90
110
131
152
172
192
5
150
MAX4249-57 TOC09
20
MAX4249-57 TOC03
150
200
INPUT OFFSET VOLTAGE (µV)
25
VCM = 0
200
VOS (µV)
NUMBER OF UNITS
30
INPUT OFFSET VOLTAGE
vs. INPUT COMMON-MODE VOLTAGE
MAX4249-57 TOC02
400 UNITS
VCM = 0
TA = +25°C
35
250
MAX4249-57 TOC01
40
OFFSET VOLTAGE
vs. TEMPERATURE
MAX4249 -57TOC06
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)
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
70
VDD = 5V
RL REFERENCED TO GND
0
100
50
100
150
200
250
VOUT SWING FROM EITHER SUPPLY (mV)
-40
-20
0.4
SHDN = VSS
380
0.3
360
0.2
340
0.1
320
2.3
2.8
3.3
3.8
4.3
60
80
-40
20
60
144
50
108
40
72
30
36
10
0
0
-36
-72
-10
PHASE
-20
-108
GAIN (dB)
GAIN
180
120
40
0.01
0.1
1
5
MAX4249-57 TOC17
VDD = 3V, 5V
RL = 50kΩ
CL = 20pF
AV = 1000
GAIN
180
0
144
-10
108
-20
72
20
36
10
0
0
-36
PHASE
-10
-80
-90
-30
-144
-100
-180
10M
-110
FREQUENCY (Hz)
100k
FREQUENCY (Hz)
3.8
4.3
4.8
5.3
1M
VDD = 3V, 5V
PSRR+
-70
-72
10k
3.3
MAX4250–MAX4254
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
-60
-108
1k
2.8
-50
-20
100
2.3
-40
-40
1M
1.8
-30
-180
10M
100k
RL = 100kΩ
SUPPLY VOLTAGE (V)
-144
10k
RL = 1kΩ
80
-40
1k
80
RL = 10kΩ
100
-30
100
60
140
VDD = 3V
100
0.001
PHASE (DEGREES)
30
40
VCM = 0
VOUT = VDD/2
RL REFERENCED TO GND
160
400
MAX4249/MAX4255/MAX4256/MAX4257
GAIN AND PHASE vs. FREQUENCY
40
180
VDD = 5V
MAX4250–MAX4254
GAIN AND PHASE vs. FREQUENCY
50
20
INPUT OFFSET VOLTAGE
vs. SUPPLY VOLTAGE
OUTPUT VOLTAGE (V)
MAX4249-57 TOC16
0
60
5.3 5.5
VDD = 3V, 5V
RL = 50kΩ
CL = 20pF
AV = 1000
-20
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
60
GAIN (dB)
4.8
40
1000
0
1.8
6
SUPPLY CURRENT (µA)
400
20
2000
SHUTDOWN SUPPLY CURRENT (µA)
SUPPLY CURRENT (µA)
0.5
SHDN = VDD
0.373
340
0
SUPPLY CURRENT
vs. OUTPUT VOLTAGE
0.6
420
0.374
SHDN = VSS
360
MAX4249-57 TOC14
MAX4249-57 TOC13
PER AMPLIFIER
SHDN = VDD
380
TEMPERATURE (°C)
SUPPLY CURRENT AND SHUTDOWN
SUPPLY CURRENT vs. SUPPLY VOLTAGE
440
400
MAX4249-57 TOC18
50
RL = 10kΩ
VOUT = 20mV
TO 4.975mV
RL = 1kΩ
VOUT = 150mV
TO 4.75mV
0.375
420
PSRR-
1
10
100
1k
10k
100k
1M
10M
FREQUENCY (Hz)
Maxim Integrated
SHUTDOWN SUPPLY CURRENT (µA)
AV (dB)
90
60
440
115
100
0.376
MAX4249-57 TOC15
RL = 2kΩ
110
RL REFERENCED TO VDD/2
VDD = 5V
VOS (µV)
AV (dB)
120
120
MAX4249-57 TOC12
PER AMPLIFIER
SUPPLY CURRENT (µA)
RL = 20kΩ
130
SUPPLY CURRENT AND SHUTDOWN
SUPPLY CURRENT vs. TEMPERATURE
460
PHASE (DEGREES)
PSRR (dB)
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)
(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.)
INPUT VOLTAGE-N0ISE DENSITY
vs. FREQUENCY
1
AV = 1 (MAX4250–MAX4254)
0.1
1k
100k
1M
10M
100
-100
HD2 HD4
VOUT = 4VP-P
fO = 1kHz
0
VIN
-20
-40
100kΩ
11kΩ
-80
10
AV = 10
VIN
fO = 3kHz
FILTER BW = 30kHz
VO
RL
1
HD2
-100
HD5
MAX4250–MAX4254
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT VOLTAGE (VDD = 5V)
VO
10kΩ
fO
-60
1s/div
100k
THD+N (%)
fO
HD3
100kΩ
11kΩ
0.1
RL = 1kΩ
0.01
HD3
RL = 10kΩ
-120
-140
-140
5k
10k
15k
10
20k
5k
MAX4250–MAX4254
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT VOLTAGE SWING (VDD = 3V)
0.1
100kΩ
0
1
VOUT
RL
100kΩ
1
0.001
fO = 20kHz, FILTER BW = 80kHz
0
1
2
3
OUTPUT VOLTAGE (VP-P)
4
5
0.1
R1
5
R2
AV = 100
R1 = 560Ω, R2 = 53kΩ
0.01
R1 = 5.6kΩ, R2 = 53kΩ
0.0001
10
AV = 10
FILTER BW = 22kHz
RL = 10kΩ TO GND
VO = 2VP-P
AV = 1
4
VOUT
RL
0.001
3
3
VIN
fO = 3kHz, FILTER BW = 30kHz
2
2
MAX4250–MAX4254
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
RL = 100kΩ
OUTPUT VOLTAGE (VP-P)
Maxim Integrated
11kΩ
0.01
RL = 10kΩ
AV = 10
fO = 3kHz
FILTER BW = 30kHz
1
OUTPUT VOLTAGE (VP-P)
VIN
AV = 10
0.1
RL = 1kΩ
0.01
RL = 100kΩ
0
MAX4249/MAX4255/MAX4256/MAX4257
TOTAL HARMONIC DISTORTION PLUS NOISE
vs. OUTPUT VOLTAGE SWING
THD+N (%)
11kΩ
VOUT
RL
1
MAX4249-57 TOC25
VIN
1
0.001
20k
FREQUENCY (Hz)
FREQUENCY (Hz)
10
15k
10k
THD+N (%)
10
MAX4249-57 TOC26
-160
THD+N (%)
10k
MAX4249-57 TOC23
20
AMPLITUDE (dBc)
-60
0.001
1k
MAX4249/MAX4255/MAX4256/MAX4257
FFT OF DISTORTION AND NOISE
RL = 1kΩ
fO = 1kHz
AV = 1
MAX4249-57 TOC21
VP-PNOISE = 760nVP-P
0
MAX4250–MAX4254
FFT OF DISTORTION AND NOISE
-40
AMPLITUDE (dBc)
5
FREQUENCY (Hz)
-20
-120
10
FREQUENCY (Hz)
VOUT = 2VP-P
-80
200nV/div
15
10
MAX4249-57 TOC22
0
10k
20
MAX4249-57 TOC24
10
25
VDD = 3V OR 5V
MAX4249-57 TOC27
100
0.1Hz TO 10HzP-P NOISE
30
MAX4249-57 TOC20
AV = 10 (MAX4249/MAX4255/
MAX4256/MAX4257)
Vn-EQUIVALENT INPUT NOISE-VOLTAGE (nV/√Hz)
OUTPUT IMPEDANCE (Ω)
1000
MAX4249-57 TOC19
OUTPUT IMPEDANCE
vs. FREQUENCY
100
1k
10k
FREQUENCY (Hz)
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
1.5V
0.01
THD+N(%)
RL TO VDD/2
RL TO GND
VOUT
200mV/div
RL TO VDD
0.5V
0.001
0.0001
10
100
1k
MAX4249-57 TOC30
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
0.6V
VOUT
20mV/div
VDD = 3V
RL = 10kΩ
CL = 100pF
VIN = 1V PULSE
VDD = 3V
RL = 10kΩ
CL = 100pF
VIN = 100V PULSE
0.5V
2µs/div
2µs/div
10k
FREQUENCY (Hz)
1.6V
VOUT
200mV/div
1V
VDD = 3V
RL = 10kΩ
CL = 100pF
VIN = 100mV PULSE
AV = 10
2µs/div
VOUT
50mV/div
1.5V
VDD = 3V
RL = 10kΩ
CL = 100pF
VIN = 10mV PULSE
AV = 10
2µs/div
CHANNEL SEPARATION vs. FREQUENCY
130
CHANNEL SEPARATION (dB)
MAX4249-57 TOC32
2V
140
MAX4249-57 TOC33
MAX4249/MAX4255/MAX4256/MAX4257
SMALL-SIGNAL PULSE RESPONSE
MAX4249-57 TOC31
MAX4249/MAX4255/MAX4256/MAX4257
LARGE-SIGNAL PULSE RESPONSE
120
110
100
90
80
70
0
1k
10k
100k
1M
10M
FREQUENCY (Hz)
8
Maxim Integrated
MAX4249–MAX4257
UCSP, Single-Supply, Low-Noise,
Low-Distortion, Rail-to-Rail Op Amps
Pin/Bump Description
PIN/BUMP
MAX4250/
MAX4255
MAX4251/
MAX4256
MAX4252/
MAX4257
MAX4252
5-PIN
SOT23
8-PIN
SO/µMAX
8-PIN
SO/µMAX
8-BUMP
UCSP
10-BUMP
UCSP
10-PIN
µMAX
14-PIN
SO
14-PIN
SO
1
6
1, 7
A1, A3
A1, C1
1, 9
1, 13
1, 7, 8,
14
OUT, OUTA,
OUTB,
OUTC,
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
4
2
2, 6
B1, B3
A2, C2
2, 8
2, 12
2, 6, 9,
13
5
7
8
A2
B1
10
14
4
MAX4249/
MAX4253
MAX4254
NAME
IN+, INA+,
INB+, INC+,
IND+
IN-, INA-,
INB-,
INC-, INDVDD
FUNCTION
Amplifier Output
Negative Supply.
Connect to
ground for singlesupply operation
Noninverting
Amplifier Input
Inverting
Amplifier Input
Positive Supply
Shutdown Input,
Connect to VDD
or leave
unconnected for
normal operation
(amplifier(s)
enabled).
—
8
—
—
A4, C4
5, 6
6, 9
—
SHDN,
SHDNA,
SHDNB
—
1, 5
—
—
—
—
5, 7,
8, 10
—
N.C.
No Connection.
Not internally
connected.
—
—
—
B2
B2, B3
—
—
—
—
Not populated
with solder
sphere
Detailed Description
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 1k" while maintaining DC accura-
Maxim Integrated
cy, and can drive capacitive loads up to 400pF without
oscillation. The input common-mode voltage range
extends from VDD - 1.1V to 200mV beyond the negative
rail. The push-pull 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 lowpower 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.
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.
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
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 (R F || R G ,
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 = 100k", RG = 11k" (AV = 10V/V) is en =
15nV/!Hz, en can be reduced to 9nV/!Hz by choosing
RF = 10k", RG = 1.1k" (AV = 10V/V), at the expense
of greater current consumption and potentially higher
distortion. For a gain of 100V/V with RF = 100k", RG =
1.1k", the en is low (9nV/!Hz).
2µs/div
Figure 2a. Pulse Response with No Feed-Forward
Compensation
AV = 2
RF = RG = 100kΩ
CZ = 11pF
100mV
50mV/div
VIN
0
100mV/div
VOUT
2µs/div
Figure 2b. Pulse Response with 10pF Feed-Forward
Compensation
10
Maxim Integrated
MAX4249–MAX4257
UCSP, Single-Supply, Low-Noise,
Low-Distortion, Rail-to-Rail Op Amps
Using a Feed-Forward Compensation
Capacitor, CZ
RISO
VOUT
CL
MAX4250
MAX4251
MAX4252
MAX4253
MAX4254
VIN
CZ = 11 x (RF / RG) [pF]
Figure 3. Overdriven Input Showing No Phase Reversal
4.25V
VOUT
0
4.45V
VIN
-200mV
0
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:
In the unity-gain stable MAX4250–MAX4254, the use of
a proper C Z is most important for A V = 2V/V, and
A V = -1V/V. In the decompensated MAX4249/
MAX4255/MAX4256/MAX4257, CZ is most important
for A V = 10V/V. Figures 2a and 2b show transient
response both with and without CZ.
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 ||
R F is greater than 20k" (MAX4250–MAX4254) or
greater than 5k" (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,
noise-sensitive applications.
AV = 1
VDD = 5V
RL = 10kΩ
20µs/div
Figure 4. Rail-to-Rail Output Operation
Ground-Sensing and Rail-to-Rail Outputs
5V
VOUT
1V/div
0
VDD = 5V
RL = 10kΩ
AV = 10
f = 1kHz
Output Loading and Stability
200µs/div
Figure 5. Capacitive-Load Driving Circuit
Maxim Integrated
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).
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
10k" load, making the devices ideal in low-supplyvoltage applications.
Even with their low quiescent current of 400µA, these
amplifiers can drive 1k" loads while maintaining excellent DC accuracy. Stability while driving heavy capacitive loads is another key feature.
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
CAPACITIVE LOADING (pF)
Figure 6. Isolation Resistance vs. Capacitive Loading to
Minimize Peaking (
工商网监
湘ICP备2023018690号
