19-1525; Rev 2; 4/01
Low-Cost, High-Slew-Rate,
Rail-to-Rail I/O Op Amps in SC70
General Description
The MAX4490/MAX4491/MAX4492 single/dual/quad,
low-cost CMOS op amps feature Rail-to-Rail
®
input and
output capability from either a single 2.7V to 5.5V sup-
ply or dual ±1.35V to ±2.75V supplies. These amplifiers
exhibit a high slew rate of 10V/µs and a gain-bandwidth
product of 10MHz. They can drive 2kΩ resistive loads
to within 55mV of either supply rail and remain unity-
gain stable with capacitive loads up to 300pF.
The MAX4490 is offered in the ultra-small, 5-pin SC70
package, which is 50% smaller than the standard 5-pin
SOT23 package. Specifications for all parts are guaran-
teed over the automotive (-40°C to +125°C) tempera-
ture range.
o
10V/µs Slew Rate
o
Rail-to-Rail Input Common-Mode Voltage Range
o
Rail-to-Rail Output Voltage Swing
o
10MHz Gain-Bandwidth Product
o
Unity-Gain Stable with Capacitive Loads
Up to 300pF
o
50pA Input Bias Current
o
Ultra-Small, 5-Pin SC70 Package (MAX4490)
Features
o
2.7V to 5.5V Single-Supply Operation
MAX4490/MAX4491/MAX4492
Ordering Information
Applications
Battery-Powered Instruments
Portable Equipment
Audio Signal Conditioning
Low-Power/Low-Voltage Applications
Sensor Amplifiers
RF Power Amplifier Control
High-Side/Low-Side Current Sensors
PART
TEMP RANGE
MAX4490AXK-T
-40°C to +125°C
MAX4490AUK-T
MAX4491AKA-T
MAX4491AUA
MAX4492AUD
MAX4492ASD
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
PIN-
PACKAGE
5 SC70-5
5 SOT23-5
8 SOT23-5
8 µMAX
14 TSSOP
14 SO
TOP
MARK
AAB
ADKQ
AADB
—
—
—
Capacitive-Load Stability
6000
5000
CAPACITIVE LOAD (pF)
4000
3000
UNSTABLE
2000
IN- 3
1000
STABLE
0
100
1k
10k
100k
RESISTIVE LOAD (Ω)
IN+
1
Pin Configurations/
Functional Diagrams
TOP VIEW
MAX4490
+ -
5
V
DD
V
SS
2
4
OUT
SOT23-5/SC70-5
Pin Configurations continued at end of data sheet.
Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd.
________________________________________________________________
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.
Low-Cost, High-Slew-Rate,
Rail-to-Rail I/O Op Amps in SC70
MAX4490/MAX4491/MAX4492
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (V
DD
to V
SS
) ....................................................6V
All Other Pins ...................................(V
SS
- 0.3V) to (V
DD
+ 0.3V)
Output Short-Circuit Duration .................................................10s
Continuous Power Dissipation (T
A
= +70°C)
5-Pin SC70 (derate 2.5mW/°C above +70°C) ............ 200mW
5-Pin SOT23 (derate 7.1mW/°C above +70°C).......... 571mW
8-Pin SOT23 (derate 5.26mW/°C above +70°C)........421 mW
8-Pin µMAX (derate 4.1mW/°C above +70°C) ........... 330mW
14-Pin TSSOP (derate 8.3mW/°C above +70°C) ....... 667mW
14-Pin SO (derate 8.3mW/°C above +70°C).............. 667mW
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
(V
DD
= 5V, V
SS
= 0, V
CM
= 0, V
OUT
= V
DD
/2, R
L
= 100kΩ connected to V
DD
/2, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical
values are at T
A
= +25°C.) (Note 1)
PARAMETER
Supply Voltage Range
Supply Current (per amplifier)
Input Offset Voltage
Input Bias Current
Input Offset Current
Input Resistance
Input Common-Mode Range
Common-Mode Rejection Ratio
Power-Supply Rejection Ratio
Large-Signal Voltage Gain
Output-Voltage Swing High
Output-Voltage Swing Low
Output Short-Circuit Current
Gain-Bandwidth Product
Input Capacitance
Phase Margin
Gain Margin
Slew Rate
Voltage-Noise Density
Current-Noise Density
Capacitive-Load Drive
SR
e
n
i
n
SYMBOL
V
DD
I
S
V
OS
I
B
I
OS
R
IN
V
CM
CMRR
PSRR
A
V
V
OH
V
OL
I
OUT(SC)
GBWP
C
IN
C
L
= 10pF
C
L
= 10pF
Measured from 10% to 90% of 4V
P-P
step
ƒ
= 10kHz
ƒ
= 10kHz
A
V(CL)
= 1, no sustained oscillations
Inferred from CMRR test
V
SS
≤
V
CM
≤
V
DD
2.7V
≤
V
DD
≤
5.5V
(V
SS
+ 0.25V)
≤
V
OUT
≤
(V
DD
- 0.25V)
Specified as
V
DD
- V
OH
Specified as
V
OL
- V
SS
Sourcing or sinking
C
L
= 10pF
R
L
= 100kΩ
R
L
= 2kΩ
R
L
= 100kΩ
R
L
= 2kΩ
R
L
= 100kΩ
R
L
= 2kΩ
65
V
SS
54
65
75
100
110
85
1.5
55
1.5
35
±50
10
5
60
10
10
12
1
300
150
200
(Note 3)
(Note 3)
(Note 3)
T
A
= +25°C
T
A
= T
MIN
to T
MAX
±0.05
±0.05
1000
V
DD
(Note 2)
CONDITIONS
MIN
2.7
0.8
±1.5
TYP
MAX
5.5
2
±10
16
±2.5
±2.5
UNITS
V
mA
mV
nA
nA
MΩ
V
dB
dB
dB
mV
mV
mA
MHz
pF
degrees
dB
V/µs
nV/
√
Hz
fA
√
Hz
pF
Note 1:
All units production tested at T
A
= +25°C. Limits over temperature guaranteed by design.
Note 2:
Guaranteed by the Power-Supply Rejection Ratio (PSRR) test.
Note 3:
Input Offset Voltage, Input Bias Current, and Input Offset Current are all tested and guaranteed at both ends of the common-
mode range.
2
_______________________________________________________________________________________
Low-Cost, High-Slew-Rate,
Rail-to-Rail I/O Op Amps in SC70
Typical Operating Characteristics
(V
DD
= 5V, V
SS
= 0, V
CM
= V
DD
/2, R
L
= 100kΩ to V
DD
/2, T
A
= +25°C, unless otherwise noted.)
MAX4490/MAX4491/MAX4492
SUPPLY CURRENT PER AMPLIFIER
vs. TEMPERATURE
MAX4490 toc 01
SUPPLY CURRENT PER AMPLIFIER
vs. SUPPLY VOLTAGE
MAX4490 toc02
INPUT OFFSET VOLTAGE
vs. TEMPERATURE
-0.2
-0.4
OFFSET VOLTAGE (mV)
-0.6
-0.8
-1.0
-1.2
-1.4
-1.6
-1.8
-2.0
MAX4490 toc03
850
800
SUPPLY CURRENT (µA)
750
700
650
V
DD
= 2.7V
600
550
500
V
DD
= 5V
1000
900
800
SUPPLY CURRENT (µA)
700
600
500
400
300
200
100
0
0
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
OUTPUT SWING HIGH
vs. TEMPERATURE
MAX4490 toc04
OUTPUT SWING LOW
vs. TEMPERATURE
MAX4490 toc05
OP AMP GAIN AND PHASE
vs. FREQUENCY
60
50
40
GAIN
GAIN (dB)
30
20
PHASE
10
0
-10
-20
100
A
V
= 1000
C
L
= 10pF
1k
10k
100k
1M
-45
-90
-135
-180
10M
45
0
MAX4490 toc06
80
70
60
V
DD
- V
OUT
(mV)
50
40
30
20
10
0
V
DD
= 5V OR 2.7V
R
L
= 100kΩ
V
DD
= 5V
R
L
= 2kΩ
80
70
60
V
OUT
- V
SS
(mV)
V
DD
= 5V
R
L
= 2kΩ
180
135
90
PHASE (DEGREES)
V
DD
= 2.7V
R
L
= 2kΩ
50
40
30
20
10
0
V
DD
= 2.7V
R
L
= 2kΩ
V
DD
= 5V OR 2.7V
R
L
= 100kΩ
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
FREQUENCY (Hz)
GAIN AND PHASE
vs. FREQUENCY (WITH C
LOAD
)
60
50
40
GAIN (dB)
30
20
10
0
-10
-20
100
1k
10k
100k
1M
FREQUENCY (Hz)
A
V
= 1000
C
LOAD
= 200pF
PHASE
GAIN
LARGE-SIGNAL GAIN
vs. TEMPERATURE
135
LARGE-SIGNAL GAIN (dB)
90
45
0
-45
-90
-135
-180
10M
80
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
PHASE (DEGREES)
120
V
DD
= 5V
MAX4490 toc08
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
-10
-20
-30
A
V
= 1
MAX4490 toc09
MAX4490 toc07
180
130
0
110
PSSR (dB)
-40
-50
-60
-70
100
90
-80
-90
-100
10
100
1k
10k
100k
1M
10M
FREQUENCY (Hz)
_______________________________________________________________________________________
3
Low-Cost, High-Slew-Rate,
Rail-to-Rail I/O Op Amps in SC70
MAX4490/MAX4491/MAX4492
Typical Operating Characteristics (continued)
(V
DD
= 5V, V
SS
= 0, V
CM
= V
DD
/2, R
L
= 100kΩ to V
DD
/2, T
A
= +25°C, unless otherwise noted.)
LARGE-SIGNAL TRANSIENT RESPONSE
(NONINVERTING)
MAX4490 toc11
MAX4490toc12
OUTPUT IMPEDANCE vs. FREQUENCY
MAX4490 toc10
TOTAL HARMONIC DISTORTION PLUS
NOISE vs. FREQUENCY
0.040
0.035
0.030
THD + NOISE (%)
A
V
= 1V/V
2Vp-p SIGNAL
500kHz LOWPASS FILTER
R
L
= 2kΩ
0.025
0.020
0.015
0.010
0.005
R
L
= 10kΩ
OUT
V/div
1k
A
V
= 1
100
OUTPUT IMPEDANCE (Ω)
IN
V/div
10
1
0.1
0.01
100
1k
10k
100k
1M
10M
FREQUENCY (Hz)
0
10
100
1k
10k
100k
A
V
= 1
FREQUENCY (Hz)
40µs/div
LARGE-SIGNAL TRANSIENT RESPONSE
(INVERTING)
MAX4490toc13
SMALL-SIGNAL TRANSIENT RESPONSE
(NONINVERTING)
MAX4490toc14
SMALL-SIGNAL TRANSIENT RESPONSE
(INVERTING)
MAX4490toc15
IN
2V/div
IN
50mV/div
IN
50mV/div
OUT
2V/div
40µs/div
OUT
50mV/div
40µs/div
A
V
= 1
OUT
50mV/div
A
V
= -1
40µs/div
A
V
= -1
POWER-UP TRANSIENT RESPONSE
MAX4490toc16
SLEW RATE vs. SUPPLY VOLTAGE
MAX4490 toc17
MAX4491/MAX4492
CROSSTALK vs. FREQUENCY
MAX4492toc18
12
10
SLEW RATE (V/µS)
8
6
4
2
0
2.5
3.0
3.5
4.0
4.5
5.0
A
V
= 1
10% TO 90% STEP
0
-20
-40
CROSSTALK (dB)
-60
-80
-100
-120
0.001
V
DD
2V/div
OUT
1V/div
4µs/div
A
V
= 1, V
IN
CONNECTED TO V
DD
/2, R
L
= 2kΩ
5.5
0.01
0.1
1
10
100
1000
SUPPLY VOLTAGE (V)
FREQUENCY (MHz)
4
_______________________________________________________________________________________
Low-Cost, High-Slew-Rate,
Rail-to-Rail I/O Op Amps in SC70
Pin Description
PIN
NAME
MAX4490
1
2
3
4
5
—
—
—
—
—
—
—
—
—
MAX4491
—
4
—
—
8
3
2
1
5
6
7
—
—
—
MAX4492
—
11
—
—
4
3
2
1
5
6
7
10, 12
9, 13
8, 14
IN+
V
SS
IN-
OUT
V
DD
INA+
INA-
OUTA
INB+
INB-
OUTB
INC+, IND+
INC-, IND-
OUTC, OUTD
Noninverting Input
Negative Supply Input. Connect to ground for single-supply operation.
Inverting Input
Amplifier Output
Positive Supply Input
Noninverting Input to Amplifier A
Inverting Input to Amplifier A
Amplifier A Output
Noninverting Input to Amplifier B
Inverting Input to Amplifier B
Amplifier B Output
Noninverting Inputs to Amplifiers C and D
Inverting Inputs to Amplifiers C and D
Amplifiers C and D Outputs
FUNCTION
MAX4490/MAX4491/MAX4492
Detailed Description
Rail-to-Rail Input Stage
The MAX4490/MAX4491/MAX4492 CMOS operational
amplifiers have parallel-connected N- and P-channel
differential input stages that combine to accept a com-
mon-mode range extending to both supply rails. The N-
channel stage is active for common-mode input
voltages typically greater than (V
SS
+ 1.2V), and the P-
channel stage is active for common-mode input volt-
ages typically less than (V
DD
- 1.2V).
the load is connected to V
DD
/2. Consistent resistive-
drive capability is (2.5 - 0.1) / 2.2 = 1.1kΩ. For the same
application, resistive-drive capability is 2.2kΩ when the
load is connected to V
DD
or V
SS
.
Applications Information
Power-Supply Considerations
The MAX4490/MAX4491/MAX4492 operate from a sin-
gle 2.7V to 5.5V supply or from dual ±1.35V to ±2.75V
supplies with typically 800µA supply current per ampli-
fier. A high power-supply rejection ratio of 100dB
allows for extended operation from a decaying battery
voltage, thereby simplifying designs for portable appli-
cations. For single-supply operation, bypass the power
supply with a 0.1µF ceramic capacitor placed close to
the V
DD
pin. For dual-supply operation, bypass each
supply to ground.
Rail-to-Rail Output Stage
The MAX4490/MAX4491/MAX4492 CMOS operational
amplifiers feature class-AB push-pull output stages that
can drive a 100kΩ load to within 1.5mV of either supply
rail. Short-circuit output current is typically ±50mA.
Figures 1a and 1b show the typical temperature depen-
dence of output source and sink currents, respectively,
for three fixed values of (V
DD
- V
OH
) and (V
OL
- V
SS
).
For example, at V
DD
= 5.0V, the load currents that main-
tain (V
DD
- V
OH
) = 100mV and (V
OL
- V
SS
) = 100mV at
T
A
= +25°C are 2.2mA and 3.3mA, respectively, when
Input Capacitance
One consequence of the parallel-connected differential
input stages for rail-to-rail operation is a relatively large
input capacitance C
IN
(typically 5pF). This introduces a
_______________________________________________________________________________________
5
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