Page 1
General Description
The MAX4322/MAX4323/MAX4326/MAX4327/MAX4329
family of operational amplifiers combines wide bandwidth
and excellent DC accuracy with Rail-to-Rail
®
operation at
the inputs and outputs. These devices require only 650µA
per amplifier and operate from either a single supply
(+2.4V to +6.5V) or dual supplies (±1.2V to ±3.25V). These
unity-gain-stable amplifiers are capable of driving 250Ω
loads and have a 5MHz gain-bandwidth product. The
MAX4323 and MAX4327 feature a low-power shutdown
mode that reduces supply current to 25µA and places the
outputs in a high-impedance state.
With their rail-to-rail input common-mode range and
output swing, these amplifiers are ideal for low-voltage,
single-supply operation. In addition, low offset voltage
and high speed make them the ideal signal-conditioning stages for precision, low-voltage data-acquisition
systems. The MAX4322/MAX4323 are available in
space-saving SOT23 packages.
________________________Applications
Battery-Powered Instruments
Portable Equipment
Data-Acquisition Systems
Signal Conditioning
Low-Power, Low-Voltage Applications
____________________________Features
♦ SOT23 Packages (MAX4322/MAX4323)
♦ +2.4V to +6.5V Single-Supply Operation
♦ Rail-to-Rail Input Common-Mode Voltage Range
♦ Rail-to-Rail Output Voltage Swing
♦ 5MHz Gain-Bandwidth Product
♦ 650µA Quiescent Current per Amplifier
♦ 700µV Offset Voltage
♦ No Phase Reversal for Overdriven Inputs
♦ Drive 250Ω Loads
♦ 25µA Shutdown Mode (MAX4323/MAX4327)
♦ Unity-Gain Stable for Capacitive Loads
up to 500pF
MAX4322/MAX4323/MAX4326/MAX4327/MAX4329
Single/Dual/Quad, Low-Cost, SOT23,
Low-Power, Rail-to-Rail I/O Op Amps
________________________________________________________________ Maxim Integrated Products 1
Typical Operating Circuit
19-1380; Rev 2a; 12/99
PART
MAX4322EUK-T
MAX4322ESA
-40°C to +85°C
-40°C to +85°C
TEMP. RANGE
PIN-
PACKAGE
5 SOT23-5
8 SO
Ordering Information
Pin Configurations appear at end of data sheet.
TOP
MARK
ACGE
—
BW
(MHz)
NO. OF
AMPS
MAX4322 5 1
PART
MAX4323 5 1
MAX4329 5 4
PIN-
PACKAGE
5 SOT23-5,
8 µMAX/SO
8 µMAX/SO/
6 SOT23-6
14 SO
Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd.
SHUTDOWN
—
Yes
—
—MAX4326 5 2 8 µMAX/SO
YesMAX4327 5 2
10 µMAX, 14 SO
MAX4323ESA
-40°C to +85°C 8 SO —
MAX4323EUA -40°C to +85°C 8 µMAX —
MAX4322EUA -40°C to +85°C 8 µMAX —
MAX4326EUA
-40°C to +85°C 8 µMAX —
MAX4326ESA -40°C to +85°C 8 SO —
MAX4327ESD -40°C to +85°C 14 SO —
MAX4327EUB
-40°C to +85°C 10 µMAX —
MAX4329ESD
-40°C to +85°C 14 SO —
Selector Guide
MAX187
MAX4322
SHDN
3
1
2
4
5
6
8
7
V
DD
+5V
AIN
VREF
GND
DOUT
SERIAL
INTERFACE
SCLK
CS
MAX4323EUT -40°C to +85°C 6 SOT23-6 AAEC
For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
Page 2
MAX4322/MAX4323/MAX4326/MAX4327/MAX4329
Single/Dual/Quad, Low-Cost, SOT23,
Low-Power, Rail-to-Rail I/O Op Amps
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
DC ELECTRICAL CHARACTERISTICS—TA= +25°C
(VCC= +5.0V, VEE= 0, VCM= 0, V
OUT
= VCC/ 2, SHDN = V
CC,
RLtied to VCC/ 2, unless otherwise noted.)
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.
Supply Voltage (VCC-VEE) ..................................................+7.5V
All Other Pins ...................................(V
CC
+ 0.3V) to (VEE- 0.3V)
Output Short-Circuit Duration.....................................Continuous
(short to either supply)
Continuous Power Dissipation (T
A
= +70°C)
5-pin SOT23-5 (derate 7.1mW/°C above +70°C) .........571mW
6-pin SOT23 (derate 7.1mW/°C Above + 70°C) ...........571mW
8-pin SO (derate 5.88mW/°C above +70°C).................471mW
8-pin µMAX (derate 4.10mW/°C above +70°C) ............330mW
10-pin µMAX (derate 5.6mW/°C above +70°C) ............444mW
14-pin SO (derate 8.00mW/°C above +70°C)...............640mW
Operating Temperature Range
MAX432_E__ ....................................................-40°C to +85°C
Maximum Junction Temperature .....................................+150°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10sec) .............................+300°C
V
CM
= VEE, V
CC
CONDITIONS
nA±1 ±12Input Offset Current
nA±50 ±150Input Bias Current
Ω0.1Output Resistance
kΩ500Differential Input Resistance
dB66 100Power-Supply Rejection Ratio
UNITSMIN TYP MAXPARAMETER
V
OUT
= 0.4V to 4.6V, RL= 250Ω 70 86
VV
EE
V
CC
Common-Mode Input
Voltage Range
±1.2 ±2.50
±0.7 ±2.0
Input Offset Voltage mV
VCM= VEE, V
CC
-1.5V < V
DIFF
< 1.5V
Inferred from CMRR test
VCC= 2.4V to 6.5V
AV= +1V/V
V
EE
≤
V
CM
≤
V
CC
62 94
Common-Mode Rejection Ratio dB
V
OUT
= 0.25V to 4.75V, RL= 100kΩ 106
VCM=
VEE, V
CC
MAX432_ESA/MAX4327ESD
All other packages
MAX432_ESA/MAX4327ESD
dBLarge-Signal Voltage Gain
All other packages 60 91
Page 3
MAX4322/MAX4323/MAX4326/MAX4327/MAX4329
Single/Dual/Quad, Low-Cost, SOT23,
Low-Power, Rail-to-Rail I/O Op Amps
_______________________________________________________________________________________ 3
DC ELECTRICAL CHARACTERISTICS—TA= -40°C to +85°C
(VCC= +5V, VEE= 0, VCM= 0, V
OUT
= VCC/ 2, SHDN = V
CC,
RLtied to VCC/ 2, unless otherwise noted.) (Note 1)
DC ELECTRICAL CHARACTERISTICS—TA= +25°C (continued)
(VCC= +5V, VEE= 0, VCM= 0, V
OUT
= VCC/ 2, SHDN = V
CC,
RLtied to VCC/ 2, unless otherwise noted.)
RL= 100kΩ
CONDITIONS
20
V2.4 6.5Operating Supply-Voltage Range
200 300
12
VOL- V
EE
100 200
MAX4322/
MAX4323
mA50Output Short-Circuit Current
UNITSMIN TYP MAXPARAMETER
VCC- V
OH
VOL- V
EE
VCC- V
OH
RL= 250Ω
VCC- V
OH
VOL- V
EE
VCC- V
OH
RL= 250Ω
RL= 100kΩ
25
mV
220 350
15
VOL- V
EE
Output Voltage Swing
120 250
MAX4326/
MAX4327/
MAX4329
Inferred from PSRR test
VCC= 2.4V
VCM= V
OUT
= VCC/ 2 µA
650
VCC= 5V 725 1100
Supply Current per Amplifier
MAX432_ESA/MAX4327ESD
VEE≤
VCM≤
V
CC
CONDITIONS
59
VCM= VEE, V
CC
Inferred from CMRR test VV
EE
V
CC
Common-Mode Input
Voltage Range
Common-Mode Rejection Ratio
nA±20Input Offset Current
µV/°C±2
dB
All other packages
Input Offset Voltage Tempco
54
UNITSMIN TYP MAX
VCM= VEE, V
CC
nA±180Input Bias Current
mV
MAX4323/MAX4327 V
0.8
SHDN Logic Threshold
2.0
µA±1 ±4
SHDN Input Current
Low
High
MAX4323/MAX4327
VCC= 5V 40 60
Shutdown Supply Current
per Amplifier
VCC= 2.4V
SHDN > 0.8V, MAX4323/MAX4327
µA
25
PARAMETER
All other packages
VCM=
VEE, V
CC
Input Offset Voltage
±6.0
MAX432_ESA/MAX4327ESD ±3.0
Page 4
MAX4322/MAX4323/MAX4326/MAX4327/MAX4329
Single/Dual/Quad, Low-Cost, SOT23,
Low-Power, Rail-to-Rail I/O Op Amps
4 _______________________________________________________________________________________
DC ELECTRICAL CHARACTERISTICS —TA= -40°C to +85°C (continued)
(VCC= +5V, VEE= 0, VCM= 0, V
OUT
= VCC/ 2, SHDN = V
CC,
RLtied to VCC/ 2, unless otherwise noted.) (Note 1)
f = 10kHz, V
OUT
= 2Vp-p, AV= +1V/V
VCC= 0 to 3V step
64 degrees
AV= +1V/V, V
OUT
= 2V step
CONDITIONS
µs
5
Phase Margin
MHzGain-Bandwidth Product
12
%0.003
dB
Total Harmonic Distortion
Gain Margin
Settling Time to 0.01% 2.0
µs1Turn-On Time
V/µsSlew Rate 2
UNITSMIN TYP MAXPARAMETER
AC ELECTRICAL CHARACTERISTICS
(VCC= +5V, VEE= 0, VCM= V
OUT
= V
CC
/ 2, SHDN = V
CC,
TA= +25°C unless otherwise noted.)
V
OUT
= 0.4V to 4.6V, RL= 250Ω
VCC= 2.4V to 6.5V
RL= 250Ω
CONDITIONS
dB66
dB62Power-Supply Rejection Ratio
Output Voltage Swing mV
350
MAX4322/
MAX4323
250
UNITSMIN TYP MAXPARAMETER
VCC- V
OH
VOL- V
EE
400
MAX4326/
MAX4327/
MAX4329
pF3Input Capacitance
f = 1kHz
nV/√Hz
22Input Noise Voltage Density
f = 1kHz pA0.4Input Noise Current Density
dB135Amp-Amp Isolation
AV= +1V/V pF250Capacitive Load Stability
Note 1: All devices are 100% tested at TA= +25°C. All temperature limits are guaranteed by design.
MAX4323/MAX4327 V
0.8
SHDN Logic Threshold
Large-Signal Voltage Gain
RL= 250Ω
VCC- V
OH
300VOL- V
EE
2.0
MAX4323/MAX4327 µA±5
SHDN Input Current
V2.4 6.5Operating Supply-Voltage Range
Low
High
VCM= VCC/ 2 mA1.2Supply Current per Amplifier
SHDN ≤ 0.8V, MAX4323/MAX4327
µA70
Shutdown Supply Current
per Amplifier
µs
1
SHDN Delay
MAX4323/MAX4327
0.2
Enable
Disable
Page 5
MAX4322/MAX4323/MAX4326/MAX4327/MAX4329
Single/Dual/Quad, Low-Cost, SOT23,
Low-Power, Rail-to-Rail I/O Op Amps
_______________________________________________________________________________________ 5
60
-40
100 1k 10k 1M 10M100k 100M
GAIN AND PHASE vs. FREQUENCY
-20
FREQUENCY (Hz)
GAIN (dB)
0
20
40
PHASE
GAIN
AV = +1000
NO LOAD
PHASE (DEGREES)
180
144
72
0
-72
-144
-180
-108
-36
36
108
MAX4322/26/29-01
60
-40
100 1k 10k 1M 10M100k 100M
GAIN AND PHASE vs. FREQUENCY
(WITH C
LOAD
)
-20
MAX4322/26/29-02
FREQUENCY (Hz)
GAIN (dB)
0
20
40
PHASE
GAIN
AV = +1000
R
L
= ∞
C
L
= 500pF
PHASE (DEGREES)
180
144
72
0
-72
-144
-180
-108
-36
36
108
0
-100
10 100 1k 100k 1M 10M10k 100M
POWER-SUPPLY REJECTION
vs. FREQUENCY
-80
MAX4322/26/29-03
FREQUENCY (Hz)
PSR (dB)
-60
-40
-20
AV = +1
__________________________________________Typical Operating Characteristics
(VCC= +5V, VEE= 0, VCM= V
CC
/ 2, SHDN = V
CC,TA
= +25°C, unless otherwise noted.)
1k 10k 10M
FREQUENCY (Hz)
100k 1M100
130
50
60
70
80
90
100
110
120
MAX4326/MAX4327/MAX4329
CHANNEL SEPARATION vs. FREQUENCY
MAX4322/26/29-04
CHANNEL SEPARATION (dB)
100
0.01
100 1k 100k 1M
10M
10k 100M
OUTPUT IMPEDANCE
vs. FREQUENCY
0.1
MAX4322/26/29-05
FREQUENCY (Hz)
OUTPUT IMPEDANCE (Ω)
1
10
AV = +1
900
500
550
600
650
700
750
800
850
-40 -25 -10 5 20 35 50 65 80 95
SUPPLY CURRENT PER AMPLIFIER
vs. TEMPERATURE
MAX4322/26/29-6
TEMPERATURE (°C)
SUPPLY CURRENT (µA)
VCC = 6.5V
VCC = 2.7V
-3.00
-2.25
-0.75
-1.50
0
1.50
0.75
2.25
3.00
-40 -25 -10 5 20 35 50 65 80 95
INPUT OFFSET VOLTAGE
vs. TEMPERATURE
MAX4322/26/29-7
TEMPERATURE (°C)
VOLTAGE (mV)
SOT23-5/6
PACKAGE
SO PACKAGE
-50
0123456
INPUT BIAS CURRENT
vs. COMMON-MODE VOLTAGE
MAX4322/26/29-8
COMMON-MODE VOLTAGE (V)
INPUT BIAS CURRENT (nA)
-40
-30
-20
-10
0
10
20
30
40
50
VCC = 2.7V
VCC = 6.5V
0
10
20
30
40
50
60
-40 -25 -10 5 20 35 50 65 80 95
MAX4323/MAX4327
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
MAX4323-11
TEMPERATURE (°C)
SHUTDOWN SUPPLY CURRENT (mA)
VCC = 6.5V
VCC = 2.7V
SHDN = 0V
Page 6
_____________________________Typical Operating Characteristics (continued)
(VCC= +5V, VEE= 0, VCM= V
CC
/ 2, SHDN = V
CC, TA
= +25°C, unless otherwise noted.)
MAX4322/MAX4323/MAX4326/MAX4327/MAX4329
Single/Dual/Quad, Low-Cost, SOT23,
Low-Power, Rail-to-Rail I/O Op Amps
6 _______________________________________________________________________________________
120
80
85
90
95
100
105
110
115
-40 -25 -10 5 20 35 50 65 80 95
COMMON-MODE REJECTION
vs. TEMPERATURE
MAX4322/26/29-10
TEMPERATURE (°C)
COMMON-MODE REJECTION (dB)
VCM = 0 TO 5.0V
VCM = -0.2V TO 5.2V
250
0
-40 -25 -10 5 20 35 50 65 80 95
MINIMUM OUTPUT VOLTAGE
vs. TEMPERATURE
50
200
MAX4322/26/29-11
TEMPERATURE (°C)
V
OUT
- V
EE
(mV)
150
100
RL TO V
CC
VCC = 6.5V, RL = 500Ω
VCC = 2.7V, RL = 100kΩ
VCC = 2.7V, RL = 500Ω
VCC = 6.5V, RL = 100kΩ
0
50
100
150
200
250
300
-40 -25 -10 5 20 35 50 65 80 95
MAXIMUM OUTPUT VOLTAGE
vs. TEMPERATURE
MAX4322/26/29-12
TEMPERATURE (°C)
V
CC
- V
OUT
(mV)
RL TO V
EE
VCC = 6.5V, RL = 500Ω
VCC = 2.7V, RL = 100kΩ (BOTTOM)
VCC = 2.7V, RL = 500Ω
VCC = 6.5V, RL = 100kΩ (TOP)
120
60
0 600
110
OUTPUT VOLTAGE: FROM V
CC
(mV)
GAIN (dB)
300
90
80
70
100 200 500
100
400
MAX4322/26/29-13
LARGE-SIGNAL GAIN
vs. OUTPUT VOLTAGE
VCC = 2.7V
RL TO V
EE
RL = 500Ω
RL = 100kΩ
RL = 10kΩ
RL = 2kΩ
120
60
0 600
110
OUTPUT VOLTAGE: FROM V
CC
(mV)
GAIN (dB)
300
90
80
70
100 200 500
100
400
MAX4322/26/29-14
LARGE-SIGNAL GAIN
vs. OUTPUT VOLTAGE
VCC = 6.5V
RL TO V
EE
RL = 500Ω
RL = 100kΩ
RL = 10kΩ
RL = 2kΩ
125
75
-40 -25 -10 5 20 35 50 65 80 95
LARGE-SIGNAL GAIN
vs. TEMPERATURE
85
115
MAX4322/26/29-15
TEMPERATURE (°C)
GAIN (dB)
105
95
80
90
120
110
100
VCC = 2.7V,
R
L
TO V
EE
VCC = 6.5V, RL TO V
CC
VCC = 2.7V, RL TO V
CC
RL = 500Ω
V
OUT
(p-p) = V
CC
- 1V
VCC = 6.5V,
R
L
TO V
EE
120
60
0 600
110
GAIN (dB)
300
90
80
70
100 200 500
100
400
MAX4322/26/29-16
LARGE-SIGNAL GAIN
vs. OUTPUT VOLTAGE
RL = 500Ω
RL = 100kΩ
RL = 10kΩ
RL = 2kΩ
VCC = 2.7V
R
L
TO V
CC
OUTPUT VOLTAGE: FROM VEE (mV)
120
60
0 600
110
GAIN (dB)
300
90
80
70
100 200 500
100
400
MAX4322/26/29-17
LARGE-SIGNAL GAIN
vs. OUTPUT VOLTAGE
VCC = 6.5V
RL TO V
CC
RL = 500Ω
RL = 100kΩ
RL = 10kΩ
RL = 2kΩ
OUTPUT VOLTAGE: FROM VEE (mV)
-60
-50
-40 -25 -10 5 20 35 50 65 80 95
INPUT BIAS CURRENT
vs. TEMPERATURE
MAX4322/26/29-9
TEMPERATURE (°C)
INPUT BIAS CURRENT (nA)
-40
-30
-20
-10
0
10
20
30
40
50
VCC = 6.5V, VCM = V
CC
VCC = 2.7V, VCM = V
EE
VCC = 2.7V, VCM = V
CC
VCC = 6.5V, VCM = V
EE
Page 7
_____________________________Typical Operating Characteristics (continued)
(VCC= +5V, VEE= 0, VCM= V
CC
/ 2, SHDN = V
CC,TA
= +25°C, unless otherwise noted.)
MAX4322/MAX4323/MAX4326/MAX4327/MAX4329
Single/Dual/Quad, Low-Cost, SOT23,
Low-Power, Rail-to-Rail I/O Op Amps
_______________________________________________________________________________________ 7
1.2
1.3
1.5
1.4
1.6
1.7
1.8
1.9
-40 -25 -10 5 20 35 50 65 80 95
MINIMUM OPERATING VOLTAGE
vs. TEMPERATURE
MAX4322/26/29-19
TEMPERATURE (°C)
MINIMUM OPERATING VOLTAGE (V)
10 100k10k
FREQUENCY (Hz)
100 1k
0.040
0
0.005
0.010
0.015
0.020
0.025
0.030
0.035
TOTAL HARMONIC DISTORTION
AND NOISE vs. FREQUENCY
MAX4322/26/29-20
THD + NOISE (%)
AV = +1
2Vp-p SIGNAL
500kHz LOWPASS FILTER
R
L
= 10kΩ TO V
CC
/ 2
0.1
0.001
4.0 4.44.2 5.04.84.6
TOTAL HARMONIC DISTORTION AND NOISE
vs. PEAK-TO-PEAK SIGNAL AMPLITUDE
MAX4322/26/29-21
PEAK-TO-PEAK SIGNAL AMPLITUDE (V)
THD + NOISE (%)
0.01
AV = +1
10kHz SINE WAVE
R
L
TO V
CC
/ 2
500kHz LOWPASS FILTER
RL = 10kΩ
RL = 100kΩ
RL = 2kΩ
RL = 250Ω
IN
TIME (200ns/div)
VOLTAGE (50mV/div)
OUT
AV = +1
SMALL-SIGNAL TRANSIENT
RESPONSE (NONINVERTING)
MAX4322/26/29-22
IN
TIME (200ns/div)
VOLTAGE (50mV/div)
OUT
AV = -1
SMALL-SIGNAL TRANSIENT
RESPONSE (INVERTING)
MAX4322/26/29-23
125
75
-40 -25 -10 5 20 35 50 65 80 95
LARGE-SIGNAL GAIN
vs. TEMPERATURE
85
115
MAX4322/26/29-18
TEMPERATURE (°C)
GAIN (dB)
105
95
80
90
120
110
100
V
OUT
(p-p) = V
CC
- 600mV
R
L
= 100kΩ
VCC = 6.5V, RL TO V
EE
VCC = 2.7V, RL TO V
CC
VCC = 2.7V, RL TO V
EE
VCC = 6.5V, RL TO V
CC
IN
TIME (2µs/div)
VOLTAGE (2V/div)
OUT
AV = +1
LARGE-SIGNAL TRANSIENT
RESPONSE (NONINVERTING)
MAX4322/26/29-24
IN
TIME (2µs/div)
VOLTAGE (2V/div)
OUT
AV = -1
LARGE-SIGNAL TRANSIENT
RESPONSE (INVERTING)
MAX4322/26/29-26
Page 8
MAX4322/MAX4323/MAX4326/MAX4327/MAX4329
Single/Dual/Quad, Low-Cost, SOT23,
Low-Power, Rail-to-Rail I/O Op Amps
8 _______________________________________________________________________________________
Pin Description
__________
Applications Information
Rail-to-Rail Input Stage
Devices in the MAX4322/MAX4323/MAX4326/MAX4327/
MAX4329 family of high-speed amplifiers have rail-torail input and output stages designed for low-voltage,
single-supply operation. The input stage consists of
separate NPN and PNP differential stages, which combine to provide an input common-mode range extending to the supply rails. The PNP stage is active for input
voltages close to the negative rail, and the NPN stage
is active for input voltages near the positive rail. The
input offset voltage is typically below 250µV. The
switchover transition region, which occurs near VCC/ 2,
has been extended to minimize the slight degradation in
CMRR caused by the mismatch of the input pairs. Their
low offset voltage, high bandwidth, and rail-to-rail common-mode range make these op amps excellent choices
for precision, low-voltage, data-acquisition systems.
Since the input stage switches between the NPN and
PNP pairs, the input bias current changes polarity as
the input voltage passes through the transition region.
To reduce the offset error caused by input bias currents flowing through external source impedances,
match the effective impedance seen by each input
(Figures 1a, 1b). High source impedances, together
Inverting Inputs for amps 1
and 2
IN1-, IN2-
Noninverting Inputs for amps
1 and 2
IN1+, IN2+
Shutdown Control for amps 1
and 2. Tie high or leave floating to enable amplifier.
SHDN1,
SHDN2
Outputs for amps 3 and 4
OUT3,
OUT4
Inverting Inputs for amps 3
and 4
IN3-, IN4-
Positive SupplyV
CC
No ConnectionN.C.
Shutdown Control. Tie high or
leave floating to enable
amplifier.
SHDN
Outputs for amps 1 and 2
OUT1,
OUT2
Inverting InputIN-
Noninverting Input IN+
Negative Supply. Ground for
single-supply operation.
V
EE
OutputOUT
SOT23-5
MAX4326
—
—
—
—
—
5
—
—
—
4
3
µMAX
2
1
SO
2, 6
3, 5
—
—
—
8
—
—
1, 7
—
—
4
—
2, 8
3, 7
5, 6
—
—
10
—
1, 9
—
—
4
—
2, 12
3, 11
5, 9
—
—
14
5, 7, 8,
10
—
1, 13
—
—
4
—
Noninverting Inputs for amps
3 and 4
IN3+, IN4+— — — —
MAX4329
2, 6
3, 5
—
8, 14
9, 13
4
—
—
1, 7
—
—
11
—
10, 12
SO/µMAX
2
3
—
—
—
7
1, 5, 8
—
—
—
—
4
6
—
MAX4322 MAX4327
NAME
MAX4323
SOT23-6
—
—
—
—
—
6
—
5
—
4
3
2
1
—
SO/µMAX
2
3
—
—
—
7
1, 5
8
—
—
—
4
6
—
PIN
FUNCTION
Page 9
MAX4322/MAX4323/MAX4326/MAX4327/MAX4329
Single/Dual/Quad, Low-Cost, SOT23,
Low-Power, Rail-to-Rail I/O Op Amps
_______________________________________________________________________________________ 9
R3
R3 = R1 R2
R1 R2
MAX4322/MAX4323
MAX4326/MAX4327
MAX4329
Figure 1a. Reducing Offset Error Due to Bias Current
(Noninverting)
R3
R3 = R1 R2
R1 R2
MAX4322/MAX4323
MAX4326/MAX4327
MAX4329
Figure 1b. Reducing Offset Error Due to Bias Current
(Inverting)
1k
1k
Figure 2. Input Protection Circuit
with the input capacitance, can create a parasitic pole
that produces an underdamped signal response.
Reducing the input impedance or placing a small (2pF
to 10pF) capacitor across the feedback resistor
improves the response.
The MAX4322/MAX4323/MAX4326/MAX4327/MAX4329’s
inputs are protected from large differential input voltages by 1kΩ series resistors and back-to-back triple
diodes across the inputs (Figure 2). For differential input
voltages less than 1.8V the input resistance is typically
500kΩ. For differential input voltages greater than 1.8V
the input resistance is approximately 2kΩ, and the input
bias current is determined by the following equation:
Rail-to-Rail Output Stage
The minimum output voltage will be within millivolts of
ground for single-supply operation where the load is
referenced to ground (VEE). Figure 3 shows the input
voltage range and output voltage swing of a MAX4322
connected as a voltage follower. With a +3V supply
and the load tied to ground, the output swings from
0.00V to 2.90V. The maximum output voltage swing
depends on the load, but will be within 350mV of a +5V
supply, even with the maximum load (500Ω to ground).
Driving a capacitive load can cause instability in most
high-speed op amps, especially those with low quiescent current. The MAX4322/MAX4323/MAX4326/
MAX4327/MAX4329 have a high tolerance for capacitive loads. They are stable with capacitive loads up to
500pF. Figure 4 gives the stable operating region for
capacitive loads. Figures 5 and 6 show the response
with capacitive loads and the results of adding an isolation resistor in series with the output (Figure 7). The
resistor improves the circuit’s phase margin by isolating the load capacitor from the op amp’s output.
I =
V - 1.8V
2k
BIAS
DIFF
Ω
Page 10
Figure 3. Rail-to-Rail Input /Output Voltage Range
Figure 4. Capacitive-Load Stability
MAX4322/MAX4323/MAX4326/MAX4327/MAX4329
Single/Dual/Quad, Low-Cost, SOT23,
Low-Power, Rail-to-Rail I/O Op Amps
10 ______________________________________________________________________________________
IN
TIME (400ns/div)
VOLTAGE (50mV/div)
OUT
A
V
= +1
C
L
= 500pF
Figure 5. Small-Signal Transient Response with
Capacitive Load
IN
TIME (400ns/div)
VOLTAGE (50mV/div)
OUT
AV = +1
C
L
= 1000pF
R
S
= 39Ω
Figure 6. Transient Response to Capacitive Load with
Isolation Resistor
IN
TIME (2µs/div)
VOLTAGE (1V/div)
OUT
VCC = 3V
A
V
= +1
Power-Up and Shutdown Mode
The MAX4322/MAX4323/MAX4326/MAX4327/MAX4329
amplifiers typically settle within 1µs after power-up.
Using the test circuit of Figure 8, Figures 9 and 10 show
the output voltage and supply current on power-up.
The MAX4323 and MAX4327 have a shutdown option.
When the shutdown pin (SHDN) is pulled low, the supply current drops below 25µA per amplifier and the
amplifiers are disabled with the outputs in a highimpedance state. Pulling SHDN high or leaving it floating enables the amplifier. In the dual-amplifier
MAX4327, the shutdown functions operate independently. Figures 11 and 12 show the output voltage and
supply current responses of the MAX4323 to a shutdown pulse.
Power Supplies and Layout
The MAX4322/MAX4323/MAX4326/MAX4327/MAX4329
operate from a single +2.4V to +6.5V power supply, or
from dual supplies of ±1.2V to ±3.25V. For single-supply
operation, bypass the power supply with a 0.1µF
ceramic capacitor in parallel with at least 1µF. For dual
supplies, bypass each supply to ground.
Good layout improves performance by decreasing the
amount of stray capacitance at the op amp’s inputs
and outputs. To decrease stray capacitance, minimize
trace lengths and resistor leads by placing external
components close to the op amp’s pins.
10,000
UNSTABLE
REGION
1000
CAPACITIVE LOAD (pF)
RL TO V
EE
V
= VCC/2
OUT
100
100 1k 100k10k
RESISTIVE LOAD (
Ω)
Page 11
Figure 11. Shutdown Output Voltage
MAX4322/MAX4323/MAX4326/MAX4327/MAX4329
Single/Dual/Quad, Low-Cost, SOT23,
Low-Power, Rail-to-Rail I/O Op Amps
______________________________________________________________________________________ 11
R
S
C
L
MAX4322/MAX4323
MAX4326/MAX4327
MAX4329
Figure 7. Capacitive-Load-Driving Circuit
V
OUT
0V TO 2.7V
STEP FOR
POWER-UP
TEST
SUPPLY-CURRENT
MONITORING POINT
V
CC
10Ω2k
10k
2k
MAX4322/MAX4323
MAX4326/MAX4327
MAX4329
Figure 8. Power-Up Test Circuit
Figure 10. Power-Up Supply Current
V
CC
TIME (5µs/div)
VOLTAGE (1V/div)
OUT
Figure 9. Power-Up Output Voltage
V
CC
(1V/div)
TIME (5µs/div)
I
CC
(500µA/div)
Figure 12. Shutdown Enable/Disable Supply Current
VCC = 2.7V
= 10kΩ
R
L
SHDN
(1V/div)
VCC = 2.7V
SHDN
(1V/div)
OUT
(0.5V/div)
TIME (2µs/div)
I
CC
(500µA/div)
TIME (2µs/div)
Page 12
MAX4322/MAX4323/MAX4326/MAX4327/MAX4329
Single/Dual/Quad, Low-Cost, SOT23,
Low-Power, Rail-to-Rail I/O Op Amps
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.
12 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 1999 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
Chip Information
MAX4322 TRANSISTOR COUNT: 170
MAX4323 TRANSISTOR COUNT: 170
MAX4326 TRANSISTOR COUNT: 340
MAX4327 TRANSISTOR COUNT: 340
MAX4329 TRANSISTOR COUNT: 680
SUBSTRATE CONNECTED TO V
EE
___________________________________________________________Pin Configurations
TOP VIEW
V
EE
IN-
IN+
1
5
V
CC
OUT
MAX4322
SOT23-5
2
3
4
IN2-
IN1+
IN2+
V
EE
1
2
8
7
V
CC
OUT2
IN1-
OUT1
MAX4326
SO/µMAX
3
4
6
5
OUT
IN1+
N.C.
V
EE
1
2
8
7
N.C.
V
CC
IN1-
N.C.
MAX4322
SO/µMAX
3
4
6
5
14
13
12
11
10
9
8
1
2
3
4
5
6
7
OUT4
IN4-
IN4+
V
EE
V
CC
IN1+
IN1-
OUT1
MAX4329
IN3+
IN3-
OUT3
OUT2
IN2-
IN2+
SO
14
13
12
11
10
9
8
1
2
3
4
5
6
7
V
CC
OUT2
IN2-
IN2+
V
EE
IN1+
IN1-
OUT1
MAX4327
N.C.
SHDN2
N.C.
N.C.
SHDN1
N.C.
SO
OUT
IN1+
N.C.
V
EE
1
2
8
7
SHDN
V
CC
IN1-
N.C.
MAX4323
SO
3
4
6
5
1
2
3
4
5
10
9
8
7
6
V
CC
OUT2
IN2-
IN2+V
EE
IN1+
IN1-
OUT1
MAX4327
µMAX
SHDN2SHDN1
V
EE
IN-
IN+
1
6
V
CC
OUT
MAX4323
SOT23-6
2
3
4
SHDN
5
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