Not Recommended for New Designs
This product was manufactured for Maxim by an outside wafer foundry
using a process that is no longer available. It is not recommended for
new designs. The data sheet remains available for existing users.
A Maxim replacement or an industry second-source may be available.
Please see the QuickView data sheet for this part or contact technical
support for assistance.
For further information, contact Maxim’s Applications Tech Support.
19-0260; Rev 1; 3/95
Single/Dual/Quad, 10MHz
Single-Supply Op Amps
________________________Applications
Portable Equipment
Battery-Powered Instruments
Signal Processing
Discrete Filters
Signal Conditioning
____________________________Features
♦ 15V/µs Min Slew Rate
♦ +3V Single-Supply Operation
♦ Guaranteed 10MHz Unity-Gain Bandwidth
♦ 2mA Supply Current per Amplifier
♦ Input Range Includes Negative Rail
♦ Outputs Short-Circuit Protected
♦ Rail-to-Rail Output Swing (to within ±50mV)
♦ µMAX Package (the smallest 8-pin SO)
______________Ordering Information
TEMP. RANGE
PIN-PACKAGE
MAX473CPA
PART
0°C to +70°C
8 Plastic DIP
MAX473CSA
0°C to +70°C
8 SO
MAX473CUA
MAX473C/D
MAX473EPA
MAX473ESA
MAX473MJA
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-55°C to +125°C
8 µMAX
Dice*
8 Plastic DIP
8 SO
8 CERDIP
Ordering Information continued on last page.
* Dice are specified at TA = +25°C, DC parameters only.
Servo-Loops
__________Typical Operating Circuit
9.9k
_________________Pin Configurations
TOP VIEW
82pF
82pF
9.9k
3V
3V
3V
9.9k
NULL
1
8
NULL
IN-
2
7
VCC
IN+
3
6
OUT
VEE
4
5
N.C.
8
VCC
MAX473
9.9k
VIN
100mVp-p
9.9k
1/4 MAX475
DIP/SO/µMAX
1/4 MAX475
1/4 MAX475
OUTA 1
1V
1V
127k
INA- 2
MAX474
A
INA+ 3
BANDPASS OUTPUT
1Vp-p at 190kHz
9.9k
1V
fo = 190kHz
Q = 10
BANDPASS FILTER
B
VEE 4
7
OUTB
6
INB-
5
INB+
DIP/SO/µMAX
Pin Configurations continued on last page.
________________________________________________________________ Maxim Integrated Products
Call toll free 1-800-998-8800 for free samples or literature.
1
MAX473/MAX474/MAX475
_______________General Description
The single MAX473, dual MAX474, and quad MAX475
are single-supply (2.7V to 5.25V), unity-gain-stable op
amps with rail-to-rail output swing. Each op amp guarantees a 10MHz unity-gain bandwidth, 15V/µs slew
rate, and 600Ω drive capability while typically consuming only 2mA supply current. In addition, the input
range includes the negative supply rail and the output
swings to within 50mV of each supply rail.
Single-supply operation makes these devices ideal for
low-power and low-voltage portable applications. With
their fast slew rate and settling time, they can replace
higher-current op amps in large-signal applications.
The MAX473/MAX474/MAX475 are available in DIP and
SO packages in the industry-standard op-amp pin
configurations. The MAX473 and MAX474 are also
offered in the µMAX package, the smallest 8-pin SO.
MAX473/MAX474/MAX475
Single/Dual/Quad, 10MHz
Single-Supply Op Amps
ABSOLUTE MAXIMUM RATINGS
Supply Voltage (VCC - VEE)......................................................7V
Input Voltage (IN+, IN-, IN_+, IN_-) .........................(VCC + 0.3V)
to (VEE - 0.3V)
Output Short-Circuit Duration.....................................Continuous
Continuous Power Dissipation (TA = +70°C)
8-Pin Plastic DIP (derate 9.09mW/°C above +70°C) ...727mW
8-Pin SO (derate 5.88mW/°C above +70°C)................471mW
8-Pin µMAX (derate 4.1mW/°C above +70°C) .............330mW
8-Pin CERDIP (derate 8.00mW/°C above +70°C)........640mW
14-Pin Plastic DIP (derate 10.00mW/°C above +70°C)...800mW
14-Pin SO (derate 8.33mW/°C above +70°C)..............667mW
14-Pin CERDIP (derate 9.09mW/°C above +70°C)......727mW
Operating Temperature Ranges
MAX47_C_ _ ......................................................0°C to +70°C
MAX47_E_ _.....................................................-40°C to +85°C
MAX47_MJ_ ...................................................-55°C to +125°C
Junction Temperatures
MAX47_C_ _/E_ _........................................................ +150°C
MAX47_MJ_ ................................................................ +175°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10sec) .............................+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
(+3V ≤ VCC ≤ +5V, VEE = 0V, VCM = 0.5V, VOUT = 0.5V, TA = +25°C, unless otherwise noted.)
PARAMETER
Input Offset Voltage
Input Bias Current
Input Offset Current
Common-Mode Voltage
SYMBOL
VOS
IB
TYP
MAX
MAX473
CONDITIONS
±0.70
±2.0
MAX474
±0.70
±2.0
MAX475
±0.80
±2.5
Current flows out of terminals
MIN
0
IOS
VCM
High
VCC - 1.9
Low
UNITS
mV
80
150
nA
±10
±30
nA
VCC - 1.7
VEE - 0.1
VEE
V
Common-Mode Rejection Ratio
CMRR
VEE ≤ VCM ≤ (VCC - 1.9V)
80
90
Power-Supply Rejection Ratio
PSRR
VCC = 2.7V to 6.0V
80
90
dB
40
nV/√Hz
Input Noise-Voltage Density
en
f = 10kHz
0.3V ≤ VOUT ≤
(VCC - 0.5V)
Large-Signal Gain
(Note 1)
AVOL
Sinking 5mA
Sourcing 5mA
Output Voltage
Slew Rate
Unity-Gain Bandwidth
(Note 2)
2
RL = no load
110
RL = 10kΩ
94
RL = 600Ω
82
90
76
VCC = 3V
100
VCC = 5V
76
VCC = 3V
dB
90
VIN+ - VIN- = +1V, RL = no load
VOL
VIN+ - VIN- = -1V, RL = no load
SR
VCC = 5V, RL = 10kΩ, CL = 20pF,
VIN+ - VIN- = +1V step
15
3V ≤ VCC ≤ 5V
10
VCC = 2.7V
105
VCC = 5V
VOH
GBW
dB
VCC - 0.05
VEE + 0.05
17
12
10
_______________________________________________________________________________________
V
V/µs
MHz
Single/Dual/Quad, 10MHz
Single-Supply Op Amps
(+3V ≤ VCC ≤ +5V, VEE = 0V, VCM = 0.5V, VOUT = 0.5V, TA = +25°C, unless otherwise noted.)
PARAMETER
Settling Time
SYMBOL
tS
Power-Up Time
tPU
Overshoot
CONDITIONS
MIN
TYP
ns
AV = +1, VIN = 1/2 VCC step, see Typical
Operating Characteristics
700
ns
CL = 150pF
10
CL = 20pF
5
RL = 10kΩ,
CL = 20pF
VCC = 5V
63
VCC = 3V
58
Gain Margin
RL = 10kΩ,
CL = 20pF
VCC = 5V
10
VCC = 3V
12
IS
Operating Supply-Voltage
Range
UNITS
400
Phase Margin
Supply Current
MAX
To 0.1%, CL = 20pF
Per amplifier
2.0
%
degrees
dB
3.0
Single supply
2.7
5.25
Dual supplies
±1.35
±2.625
mA
V
ELECTRICAL CHARACTERISTICS
(+3V ≤ VCC ≤ +5V, VEE = 0V, VCM = 0.5V, VOUT = 0.5V, TA = 0°C to +70°C, unless otherwise noted.)
PARAMETER
Input Offset Voltage
Input Bias Current
SYMBOL
VOS
IB
Input Offset Current
CONDITIONS
MIN
TYP
MAX
MAX473
±2.0
MAX474
±2.0
MAX475
±3.0
Current flows out of terminals
0
IOS
175
±35
UNITS
mV
nA
nA
Common-Mode Rejection Ratio
CMRR
VEE ≤ VCM ≤ (VCC - 1.9V)
78
dB
Power-Supply Rejection Ratio
PSRR
VCC = 2.7V to 6.0V
78
dB
AVOL
0.4V ≤ VOUT ≤
(VCC - 0.6V)
VOH
VIN+ - VIN- = +1V, RL = no load
VOL
VIN+ - VIN- = -1V, RL = no load
Slew Rate
SR
VCC = 5V, RL = 10kΩ, CL = 20pF,
VIN+ - VIN- = +1V step
Supply Current
IS
Per amplifier
Large-Signal Gain
(Note 1)
Output Voltage
Operating Supply-Voltage
Range
RL = 10kΩ
94
RL = 600Ω
80
dB
VCC - 0.07
VEE + 0.07
12
V
V/µs
3.3
Single supply
2.7
5.25
Dual supplies
±1.35
±2.625
mA
V
_______________________________________________________________________________________
3
MAX473/MAX474/MAX475
ELECTRICAL CHARACTERISTICS (continued)
MAX473/MAX474/MAX475
Single/Dual/Quad, 10MHz
Single-Supply Op Amps
ELECTRICAL CHARACTERISTICS
(+3V ≤ VCC ≤ +5V, VEE = 0V, VCM = 0.5V, VOUT = 0.5V, TA = -40°C to +85°C, unless otherwise noted.)
PARAMETER
Input Offset Voltage
Input Bias Current
Input Offset Current
SYMBOL
VOS
IB
CONDITIONS
MIN
TYP
MAX
MAX473
±2.3
MAX474
±2.3
MAX475
±3.3
Current flows out of terminals
0
200
IOS
±50
UNITS
mV
nA
nA
Common-Mode Rejection Ratio
CMRR
VEE ≤ VCM ≤ (VCC - 2.0V)
72
dB
Power-Supply Rejection Ratio
PSRR
VCC = 2.7V to 6.0V
72
dB
AVOL
0.4V ≤ VOUT ≤
(VCC - 0.6V)
VOH
VIN+ - VIN- = +1V, RL = no load
VOL
VIN+ - VIN- = - 1V, RL = no load
Slew Rate
SR
VCC = 5V, RL = 10kΩ, CL = 20pF,
VIN + - VIN- = +1V step
Supply Current
IS
Per amplifier
Large-Signal Gain
(Note 1)
Output Voltage
Operating Supply-Voltage
Range
RL = 10kΩ
94
RL = 600Ω
72
dB
VCC - 0.08
VEE + 0.08
10
V
V/µs
3.4
Single supply
2.7
5.25
Dual supplies
±1.35
±2.625
mA
V
ELECTRICAL CHARACTERISTICS
(+3V ≤ VCC ≤ +5V, VEE = 0V, VCM = 0.5V, VOUT = 0.5V, TA = -55°C to +125°C, unless otherwise noted.)
PARAMETER
Input Offset Voltage
Input Bias Current
Input Offset Current
SYMBOL
VOS
IB
CONDITIONS
MIN
TYP
MAX
MAX473
±2.8
MAX474
±2.8
MAX475
±4.0
Current flows out of terminals
0
225
IOS
±60
UNITS
mV
nA
nA
Common-Mode Rejection Ratio
CMRR
VEE ≤ VCM ≤ (VCC - 2.15V)
70
dB
Power-Supply Rejection Ratio
PSRR
VCC = 2.7V to 6.0V
70
dB
AVOL
0.5V ≤ VOUT ≤
(VCC - 0.6V)
VOH
VIN+ - VIN- = +1V, RL = no load
VOL
VIN+ - VIN- = -1V, RL = no load
Slew Rate
SR
VCC = 5V, RL = 10kΩ, CL = 20pF,
VIN+ - VIN- = +1V step
Supply Current
IS
Per amplifier
Large-Signal Gain
(Note 1)
Output Voltage
Operating Supply-Voltage
Range
RL = 10kΩ
90
RL = 600Ω
70
dB
VCC - 0.1
VEE + 0.1
9
V/µs
3.6
Single supply
2.7
5.25
Dual supplies
±1.35
±2.625
mA
V
Note 1: Gain decreases to zero as the output swings beyond the specified limits.
Note 2: Guaranteed by correlation to slew rate.
4
V
_______________________________________________________________________________________
Single/Dual/Quad, 10MHz
Single-Supply Op Amps
SUPPLY CURRENT PER AMPLIFIER
vs. SUPPLY VOLTAGE
2.5
100
VCC = 5V
2.5
80
1.5
IB (nA)
IS (mA)
IS (mA)
2.0
2.0
473 TOC-03
120
473 TOC-02
3.0
473 TOC-01
3.0
INPUT BIAS CURRENT
vs. TEMPERATURE
SUPPLY CURRENT vs. TEMPERATURE
VCC = 3V
60
1.0
40
0.5
20
1.5
2
3
4
5
0
-60
6
-20
20
VCC-VEE (V)
GAIN-BANDWIDTH PRODUCT
vs. TEMPERATURE
60
100
SLEW RATE vs. TEMPERATURE
MAXIMUM OUTPUT VOLTAGE
vs. LOAD RESISTANCE
5.2
VCC = 5V
140
VCC = 5V
5.1
VOUT MAX (V)
SLEW RATE (V/µs)
20
TEMPERATURE (°C)
14
5.0
VCC
4.9
VCC = 3V
1V
11
13
4.8
RL
60
100
140
-20
20
60
100
0.1
1
10
100
1000
LOAD RESISTANCE (kΩ)
MAXIMUM OUTPUT VOLTAGE
vs. LOAD RESISTANCE
3.1
140
TEMPERATURE (°C)
TEMPERATURE (°C)
MINIMUM OUTPUT VOLTAGE
vs. LOAD RESISTANCE
VCC = 3V
0.5
VCC
2.9
VCC
RL
1V
0.4
3.0
473 TOC-08
20
4.7
VOUT MIN (V)
-20
8
-60
473 TOC-07
12
-60
VOUT MAX (V)
GBW (MHz)
14
-20
TEMPERATURE (°C)
17
15
0
-60
140
473 TOC-05
AVCL = 40dB
100
20
473 TOC-04
16
60
473 TOC-06
1.0
0.3
0.2
1V
2.8
0.1
RL
2.7
0.1
1
10
100
LOAD RESISTANCE (kΩ)
1000
VCC = 5V
VCC = 3V
0
0.1
1
10
100
1000
10,000
LOAD RESISTANCE (kΩ)
_______________________________________________________________________________________
5
MAX473/MAX474/MAX475
__________________________________________Typical Operating Characteristics
(VCC = 5V, VEE = 0V, TA = +25°C, unless otherwise noted.)
____________________________Typical Operating Characteristics (continued)
(VCC = 5V, VEE = 0V, TA = +25°C, unless otherwise noted.)
MAXIMUM OUTPUT VOLTAGE
vs. TEMPERATURE
30
VCC = 3V
-20
20
60
100
1V
VCC = 3V
VCC
5
0
-60
140
20
60
100
OPEN-LOOP GAIN vs. TEMPERATURE
OVERSHOOT vs. CAPACITIVE LOAD
473 TOC-12
40
OVERSHOOT (%)
RL = 600Ω
50
RL = NO LOAD
20
VCC = 3V
0.5V STEP
10
VCC = 5V
1.0V STEP
30
10
-60
1000
20
60
100
1
140
10
1000
100
10
100
1k
-60
AV = +1
VIN = 1.5Vp-p
THD + NOISE (dB)
-70
-75
-80
-85
-90
10
100
1k
FREQUENCY (Hz)
10k
1000
10,000
100
FREQUENCY (Hz)
-65
10
100
TOTAL HARMONIC DISTORTION
AND NOISE vs. FREQUENCY
473 TOC-15
CURRENT-NOISE DENSITY (pA/√Hz)
INPUT REFERRED
10
INPUT REFERRED
CAPACITIVE LOAD (pF)
CURRENT-NOISE DENSITY
vs. FREQUENCY
100
1
10
0
-20
TEMPERATURE (°C)
6
0.1
VOLTAGE-NOISE DENSITY
vs. FREQUENCY
30
70
95
LOAD RESISTANCE (kΩ)
110
90
105
140
TEMPERATURE (°C)
RL = 10kΩ
VCC = 5V
85
-20
TEMPERATURE (°C)
130
473 TOC-11
473 TOC-10
VCC = 5V
10
VCC = 3V
115
473 TOC-17
0
-60
15
473 TOC-13
10
VCC = 5V
125
OPEN-LOOP VOLTAGE GAIN (dB)
40
20
20
VOLTAGE-NOISE DENSITY (nV/√Hz)
VCC
VOUT MAX, VCC -VOUT (mV)
VOUT MIN, IVEE -VOUTI (mV)
1V
473 TOC-09
50
OPEN-LOOP VOLTAGE GAIN
vs. LOAD RESISTANCE
473 TOC-14
MINIMUM OUTPUT VOLTAGE
vs. TEMPERATURE
OPEN-LOOP GAIN (dB)
MAX473/MAX474/MAX475
Single/Dual/Quad, 10MHz
Single-Supply Op Amps
100k
10
100
1k
10k
100k
FREQUENCY (Hz)
_______________________________________________________________________________________
10k
100k
Single/Dual/Quad, 10MHz
Single-Supply Op Amps
1
180
VCC = 3V ± 300mV
50
40
GAIN
36
-1
0
PHASE
-36
-2
-72
VCC = 5V ± 250mV
30
GAIN
GAIN (dB)
GAIN (dB)
60
100
1000
1k
10k
100k
FREQUENCY (kHz)
1M
-144
-180
1k
10k
144
VCC = 5V
40
GAIN
-72
10k
-144
100
10k
100k
1M
10M
0
-36
-72
-20
10k
-108
10k
20pF
-40
-144
100
-180
1k
10k
100k
FREQUENCY (Hz)
1M
10M
FREQUENCY (Hz)
0.1Hz to 10Hz VOLTAGE NOISE
INPUT REFERRED VOLTAGE (2µV/div)
144
36
PHASE
0
-180
1k
180
72
-108
10k
20pF
10M
108
20
GAIN (dB)
-36
-20
1M
PHASE (DEGREES)
0
PHASE (DEGREES)
36
473 TOC-22
180
72
PHASE
100k
FREQUENCY (Hz)
108
20
GAIN (dB)
-108
GAIN AND PHASE vs. FREQUENCY
473 TOC-21
VCC = 3V
-40
-36
FREQUENCY (Hz)
GAIN
0
PHASE
-4
10M
GAIN AND PHASE vs. FREQUENCY
40
0
-2
-72
-180
10
36
-144
20
1
72
-1
-3
-108
-3
144
PHASE (DEGREES)
72
180
108
0
108
0
VCC = 5V
RL = 10kΩ II 20pF
144
PHASE (DEGREES)
PSRR (dB)
VCC = 3V
RL = 10kΩ II 20pF
1
70
473 TOC-19
473 TOC-23
80
UNITY-GAIN FOLLOWER
FREQUENCY RESPONSE
UNITY-GAIN FOLLOWER
FREQUENCY RESPONSE
473 TOC-20
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
POWER-UP TIME
A
1k
1k
B
100k 10pF
500ns/div
1sec/div
A : VCC, 5V/div
B : VOUT, 1V/div
_______________________________________________________________________________________
7
MAX473/MAX474/MAX475
____________________________Typical Operating Characteristics (continued)
(VCC = 5V, VEE = 0V, TA = +25°C, unless otherwise noted.)
MAX473/MAX474/MAX475
Single/Dual/Quad, 10MHz
Single-Supply Op Amps
____________________________Typical Operating Characteristics (continued)
(VCC = 5V, VEE = 0V, TA = +25°C, unless otherwise noted.)
SMALL-SIGNAL TRANSIENT RESPONSE
(VCC = 5V)
SMALL-SIGNAL TRANSIENT RESPONSE
(VCC = 3V)
A
A
0.5V
0.5V
B
B
0.5V
0.5V
200ns/div
200ns/div
VCC = 5V, AV = +1, RL = 10kΩ, CL = 220pF
A : VIN, 50mV/div
B : VOUT, 50mV/div
VCC = 3V, AV = +1, RL = 10kΩ, CL = 100pF
A : VIN, 50mV/div
B : VOUT, 50mV/div
LARGE-SIGNAL TRANSIENT RESPONSE
OVERDRIVING THE OUTPUT
A
0.5V
A
1.5V
B
B
0.5V
0V
200ns/div
VCC = 5V, AV = +1, RL = 10kΩ, CL = 220pF
A : VIN, 1V/div
B : VOUT, 500mV/div
8
200ns/div
VCC = 5V, VIN- = 2.0V, RL = 10kΩ, CL = 33pF
A : VIN+, 1V/div
B : VOUT, 1V/div
_______________________________________________________________________________________
Single/Dual/Quad, 10MHz
Single-Supply Op Amps
PIN
NAME
FUNCTION
MAX473
MAX474
MAX475
1, 8
—
—
NULL
Offset Null Input. Connect to one end of 2kΩ potentiometer for offset voltage
trimming. Connect wiper to VEE. See Figure 1.
—
1
1
OUTA
Amplifier A Output
2
—
—
IN-
—
2
2
INA-
Inverting Input
Amplifier A Inverting Input
3
—
—
IN+
Noninverting Input
—
3
3
INA+
4
4
11
VEE
Negative Power-Supply Pin. Connect to ground or a negative voltage.
5
—
—
N.C.
No Connect—not internally connected
—
5
5
INB+
Amplifier B Noninverting Input
6
—
—
OUT
Amplifier Output
—
6
6
INB-
Amplifier B Inverting Input
—
7
7
OUTB
7
8
4
VCC
—
—
8
OUTC
—
—
9
INC-
Amplifier C Inverting Input
—
—
10
INC+
Amplifier C Noninverting Input
—
—
12
IND+
Amplifier D Noninverting Input
—
—
13
IND-
Amplifier D Inverting Input
—
—
14
OUTD
Amplifier A Noninverting Input
Amplifier B Output
Positive Power-Supply Pin. Connect to (+) terminal of power supply.
Amplifier C Output
Amplifier D Output
__________Applications Information
Power Supplies
The MAX473/MAX474/MAX475 operate from a single
2.7V to 5.25V power supply, or from dual supplies of
±1.35V to ±2.625V. For single-supply operation,
bypass the power supply with 0.1µF. If operating from
dual supplies, bypass each supply to ground. With
0.1µF bypass capacitance, channel separation
(MAX474/MAX475) is typically better than 120dB with
signal frequencies up to 300kHz. Increasing the
bypass capacitance (e.g. 10µF || 0.1µF) maintains
channel separation at higher frequencies.
Minimizing Offsets
The MAX473’s maximum offset voltage is ±2mV
(TA = +25°C). If additional offset adjustment is required,
connect a 2kΩ trim potentiometer between pins 1, 8, and
4 (Figure 1). Input offset voltage for the dual MAX474
and quad MAX475 cannot be externally trimmed.
The MAX473/MAX474/MAX475 are bipolar op amps
with low input bias currents. The bias currents at both
inputs flow out of the device. Matching the resistance
at the op amp’s inputs significantly reduces the offset
error caused by the bias currents. Place a resistor (R3)
from the noninverting input to ground when using the
inverting configuration (Figure 2a); place R3 in series
with the noninverting input when using the noninverting
configuration (Figure 2b). Select R3 such that the parallel combination of R2 and R1 equals R3. Adding R3 will
slightly increase the op amp’s voltage noise.
Output Loading and Stability
The MAX473/MAX474/MAX475 op amps are unity-gain
stable. Any op amp’s stability depends on the configuration, closed-loop gain, and load capacitance. The
unity-gain, noninverting buffer is the most sensitive gain
configuration, and driving capacitive loads decreases
stability.
_______________________________________________________________________________________
9
MAX473/MAX474/MAX475
______________________________________________________________Pin Description
MAX473/MAX474/MAX475
Single/Dual/Quad, 10MHz
Single-Supply Op Amps
R2
R1
VIN
2k
VOUT
1
NULL 8
NULL
R3
MAX473
4
R3 = R2R1
Figure 2a. Reducing Offset Error Due to Bias Current:
Inverting Configuration
VEE
Figure 1. Offset Null Circuit
R3
VIN
VOUT
The MAX473/MAX474/MAX475 have excellent phase
margin (the difference between 180° and the unity-gain
phase angle). It is typically 63° with a load of 10kΩ in
parallel with 20pF. Generally, higher phase margins
indicate greater stability.
Capacitive loads form an RC network with the op amp’s
output resistance, causing additional phase shift that
reduces the phase margin. Figure 3 shows the
MAX473/MAX474/MAX475 output response when driving a 390pF load in parallel with 10kΩ.
When driving large capacitive loads, add an output isolation resistor, as shown in Figure 4. This resistor
improves the phase margin by isolating the load
capacitance from the amplifier output. Figure 5 shows
the MAX473/MAX474/MAX475 driving a capacitive load
of 1000pF using the circuit of Figure 4.
Feedback Resistors
The feedback resistors appear as a resistance network
to the op amp’s feedback input (Figure 2). This resistance, combined with the op amp’s input and stray
capacitance (total input capacitance), forms a pole that
adds unwanted phase shift when either the total input
capacitance or feedback resistance is too large. For
example, using the noninverting configuration with a
gain of 10, if the total capacitance at the negative input
is 10pF and the effective resistance (R1 || R2) is 9kΩ,
this RC network introduces a pole at fo = 1.8MHz. At
10
R2
R1
R3 = R2R1
Figure 2b. Reducing Offset Error Due to Bias Current:
Noninverting Configuration
input frequencies above fo, the pole introduces additional phase shift, which reduces the overall bandwidth
and adversely affects stability. Choose feedback resistors small enough so they do not adversely affect the
op amp’s operation at the frequencies of interest.
Overdriving the Outputs
The output voltage swing for specified operation is from
(VEE + 0.3V) to (VCC - 0.5V) (see Electrical Characteristics).
Exercising the outputs beyond these limits drives the output transistors toward saturation, resulting in bandwidth
degradation, response-time increase, and gain decrease
(which affects linearity). Operation in this region causes a
slight distortion in the output waveform, but does not
adversely affect the op amp.
______________________________________________________________________________________
Single/Dual/Quad, 10MHz
Single-Supply Op Amps
MAX473/MAX474/MAX475
Driving 390pF in parallel with 10kΩ,
VCC = 5V, buffer configuration
Figure 3. MAX474 Driving 390pF
Figure 5. The MAX473 easily drives 1000pF using the
Capacitive-Load Driving Circuit (Figure 4).
MAX473/MAX474/
MAX475
RL
10Ω
VOUT
VIN
CL
MAX473-FIG6
FULL-POWER BANDWIDTH (MHz)
100
SMALL-SIGNAL
GAIN BANDWIDTH
10
1
FULL-POWER
BANDWIDTH
0.1
0
1
2
3
4
OUTPUT VOLTAGE SWING (Vp-p)
Figure 4. Capacitive-Load Driving Circuit
Figure 6. Full-Power Bandwidth vs. Peak-to-Peak AC Voltage
Full-Power Bandwidth
Layout
The MAX473/MAX474/MAX475’s fast 15V/µs slew rate
maximizes full-power bandwidth (FPBW). The FPBW is
given by:
A good layout improves performance by decreasing
the amount of stray capacitance at the amplifier’s
inputs and output. Since stray capacitance might be
unavoidable, minimize trace lengths and resistor leads,
and place external components as close to the pins as
possible.
SR
FPBW (Hz) = —————————————
π [VOUT peak-to-peak(max)]
where the slew rate (SR) is 15V/µs min. Figure 6 shows
the full-power bandwidth as a function of the peak-topeak AC output voltage.
______________________________________________________________________________________
11
MAX473/MAX474/MAX475
Single/Dual/Quad, 10MHz
Single-Supply Op Amps
_Ordering Information (continued)
TEMP. RANGE
PIN-PACKAGE
MAX474CPA
PART
0°C to +70°C
8 Plastic DIP
MAX474CSA
0°C to +70°C
8 SO
MAX474CUA
MAX474C/D
MAX474EPA
MAX474ESA
MAX474MJA
MAX475CPD
MAX475CSD
MAX475EPD
MAX475ESD
MAX475MJD
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-55°C to +125°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
-55°C to +125°C
8 µMAX
Dice*
8 Plastic DIP
8 SO
8 CERDIP
14 Plastic DIP
14 SO
14 Plastic DIP
14 SO
14 CERDIP
_________________Chip Topographies
MAX473
NULL
NULL
IN-
V CC
IN+
0.065"
(1.651mm)
OUT
V EE
0.052"
(1.321mm)
* Dice are specified at TA = +25°C, DC parameters only.
TRANSISTOR COUNT: 185
SUBSTRATE CONNECTED TO VEE
____Pin Configurations (continued)
MAX474
V CC
TOP VIEW
OUTA 1
INA- 2
INA+ 3
14 OUTD
A
VCC 4
INB+ 5
INB- 6
D
C
OUTB 7
OUTB
OUTA
12 IND+
11 VEE
MAX475
B
13 IND-
INA-
INB0.084"
(2.134mm)
INA+
INB+
10 INC+
9
INC-
8
OUTC
DIP/SO
V EE
0.058"
(1.473mm)
TRANSISTOR COUNT: 355
SUBSTRATE CONNECTED TO VEE
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
© 1995 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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