19-1526; Rev 1; 10/99
Micropower, SOT23, Rail-to-Rail,
Fixed-Gain, GainAmp/Open-Loop Op Amps
General Description Features
The MAX4074–MAX4078 GainAmp™ op amp family combines low-cost Rail-to-Rail® op amps with precision internal gain-setting resistors. Factory-trimmed on-chip resistors decrease design size, cost, and layout, and provide 0.1% gain accuracy. Fixed inverting gains from
-0.25V/V to -100V/V or noninverting gains from +1.25V/V to +101V/V are available. These devices operate from a single +2.5V to +5.5V supply and consume just 34µA. GainAmp amplifiers are optimally compensated for each gain version, achieving gain bandwidth (GBW) products up to 4MHz (AV = +25V/V to +101V/V). High-voltage fault protection withstands ±17V at either input without damage or excessive current draw (MAX4074/MAX4075 only).
Two versions are available in this amplifier family. The MAX4076/MAX4077/MAX4078 are single/dual/quad open-loop, unity-gain-stable op amps, and the MAX4074/MAX4075 are single/dual fixed-gain op amps. The input common-mode voltage range of the open-loop amplifiers extends from 150mV below the negative supply to within 1.2V of the positive supply.
♦ Internal Gain-Setting Resistors in SOT23 Packages (MAX4074)
♦ 0.1% Gain Accuracy (RF/RG) (MAX4074/75)
♦ 54 Standard Gains Available (MAX4074/75)
♦ Open-Loop, Unity-Gain-Stable Op Amps (MAX4076/77/78)
♦ Rail-to-Rail Outputs Drive 1k Load (MAX4074/75)
♦ +2.5V to +5.5V Single Supply
♦ 34µA Supply Current (MAX4074/75)
♦ Up to 4MHz GBW Product
♦ Fault-Protected Inputs Withstand ±17V (MAX4074/75)
♦ 200pA max Input Bias Current (MAX4076/77/78)
♦ Stable with Capacitive Loads up to 100pF with No Isolation Resistor
Ordering Information
The GainAmp outputs can swing rail-to-rail and drive a 1k load while maintaining excellent DC accuracy
PART | TEMP. RANGE | PIN- PACKAGE | TOP MARK |
MAX4074__EUK-T | -40°C to +70°C | 5 SOT23-5 | ** |
MAX4074__ESA | -40°C to +70°C | 8 SO | — |
(MAX4074/MAX4075 only). The amplifiers are stable for capacitive loads up to 100pF.
For space-critical applications, the MAX4074/MAX4076 are available in space-saving SOT23-5 packages.
Applications
Portable Battery-Powered Equipment Instruments, Terminals, and Bar-Code Readers Keyless Entry
Photodiode Preamps Smart-Card Readers
Infrared Receivers for Remote Controls Low-Side Current-Sense Amplifiers
Gain Selector Guide appears at end of data sheet. Typical Operating Circuit appears at end of data sheet.
GainAmp is a trademark of Maxim Integrated Products.
Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd.
Ordering Information continued at end of data sheet.
Note: Insert the desired gain code in the blank to complete the part number (see the Gain Selector Guide).
**See the Gain Selector Guide for a list of preferred gains and top marks.
Pin Configurations/
TOP VIEW MAX4074 OUT 1 5 VCC RF VEE 2 RG IN+ 3 4 IN- SOT23-5 Pin Configurations continued at end of data sheet. |
Maxim Integrated Products 1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 1-800-835-8769.
Supply Voltages (VCC to VEE) ..................................-0.3V to +6V
Voltage Inputs (IN_)
MAX4076/MAX4077/MAX4078 .....(VCC + 0.3V) to (VEE - 0.3V) MAX4074/MAX4075..........................................................±17V
Output Short-Circuit Duration to Either Supply (OUT_)....Continuous Continuous Power Dissipation (TA = +70°C)
5-Pin SOT23 (derate 7.1mW/°C above +70°C) ............571mW
14-Pin TSSOP (derate 6.3mW/°C above +70°C) ..........500mW
8-Pin µMAX (derate 4.1mW/°C above +70°C) ..............330mW
8-Pin SO (derate 5.88mW/°C above +70°C).................471mW
14-Pin SO (derate 8.33mW/°C above +70°C)...............667mW
Operating Temperature Range ...........................-40°C to +85°C Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°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.
(VCC = +2.5V to +5.5V, VEE = 0, VIN+ = VIN- = VCC/2, RL = to VCC/2, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) (Note 1)
PARAMETER | SYMBOL | CONDITIONS | MIN | TYP | MAX | UNITS | |
Supply Voltage Range | VCC | Guaranteed by PSRR test | 2.5 | 5.5 | V | ||
Supply Current (per amplifier) | ICC | VCC = 5V | 37 | 55 | µA | ||
VCC = 3V | 34 | 50 | |||||
Input Offset Voltage | VOS | RL = 1M | 0.2 | 3.5 | mV | ||
Input Offset Voltage Drift | 0.3 | µV/°C | |||||
Input Bias Current (Note 2) | IIN+_ | 0.8 | 1000 | pA | |||
Inverting Input Resistance | RIN_ | AV < +25V/V | 300 | k | |||
AV +25V/V | 80 | ||||||
Noninverting Input Resistance | RIN_+ | 1000 | M | ||||
Positive Input Voltage Range | IN_+ | Guaranteed by functional test (Note 3) | VEE - 0.15 | VCC - 1.2 | V | ||
Negative Input Voltage Range | IN_- | Guaranteed by functional test (Note 3) | ±15 | V | |||
Power-Supply Rejection Ratio | PSRR | VCC = 2.5V to 5.5V | 70 | 96 | dB | ||
Closed-Loop Output Impedance | ROUT | 0.2 | | ||||
Output Short-Circuit Current | Shorted to VCC | 5 | mA | ||||
Shorted to VEE | -22 | ||||||
Output Voltage Swing (Note 4) | RL = 1M | VCC - VOH | 0.5 | 2.5 | mV | ||
VOL - VEE | 0.4 | 2.5 | |||||
RL = 10k | VCC - VOH | 25 | 150 | ||||
VOL - VEE | 11 | 80 | |||||
RL = 1k | VCC - VOH | 300 | 1000 | ||||
VOL - VEE | 100 | 600 |
(VCC = +2.5V to +5.5V, VEE = 0, VIN+ = VIN- = VCC/2, RL = to VCC/2, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) (Note 1)
PARAMETER | SYMBOL | CONDITIONS | MIN TYP MAX | UNITS | |
Power-Up Time | Output settling to 1% | 9 | ms | ||
Slew Rate | SR | VOUT = 4V step | 100 | V/ms | |
Settling Time (to 0.01%) | VOUT = 4V step | 60 | µs | ||
Input Voltage Noise Density | en | f = 5kHz (Note 5) | 150 | nV/Hz | |
Input Noise Current Density | f = 5kHz | 500 | fA/Hz | ||
Capacitive Load Stability | CLOAD | No sustained oscillations | 500 | pF | |
DC Gain Accuracy | (VEE + 25mV) < VOUT < (VCC - 25mV), RL = 1M (Note 6) | TA = +25°C | 0.01 1.0 | % | |
TA = TMIN to TMAX | 1.2 | ||||
-3dB Bandwidth | BW (-3dB) | AV = +1.25V/V | 200 | kHz | |
AV = +3V/V | 90 | ||||
AV = +5V/V | 80 | ||||
AV = +10V/V | 90 | ||||
AV = +25V/V | 120 |
(VCC = +2.5V to +5.5V, VEE = 0, VIN+ = VIN- = VCC/2, RL = to VCC/2, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) (Note 1)
PARAMETER | SYMBOL | CONDITIONS | MIN | TYP | MAX | UNITS |
Supply Voltage Range | VCC | Guaranteed by PSRR test | 2.5 | 5.5 | V | |
Supply Current (per amplifier) | ICC | VCC = 5V | 45 | 60 | µA | |
VCC = 3V | 40 | 55 | ||||
Input Offset Voltage | VOS | RL = 1M | 1.2 3.5mV | mV | ||
Input Offset Voltage Drift | 1.5µV | µV/°C | ||||
Input Bias Current (Note 2) | IIBIAS | 1 | 200 | pA | ||
Input Offset Current | IOS | ±0.4 | pA | |||
Common-Mode Input Voltage Range | IVR | Guaranteed by CMRR | 0.15 VCC - 1.2 | V | ||
Common-Mode Rejection Ratio | CMRR | (VCC - 1.2V) VCM -0.15V | 70 | 95 | dB | |
Power-Supply Rejection Ratio | PSRR | VCC = 2.5V to 5.5V | 70 | 95 | dB | |
Closed-Loop Output Impedance | ROUT | AV = +1V/V | 0.2 | | ||
Output Short-Circuit Current | Shorted to VCC | 4.5 | mA | |||
Shorted to VEE | 20 | |||||
Large-Signal Voltage Gain | AVOL | 0.05V < VOUT < (VCC - 0.1V), RL = 1M | 80 | 117 | dB | |
0.25V < VOUT < (VCC - 0.3V), RL = 10k | 80 | 95 | ||||
0.25V < VOUT < (VCC - 0.3V), RL = 5k | 80 | 93 |
(VCC = +2.5V to +5.5V, VEE = 0, VIN+ = VIN- = VCC/2, RL = to VCC/2, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) (Note 1)
PARAMETER | SYMBOL | CONDITIONS | MIN TYP | MAX | UNITS | |
Output Voltage Swing | VOH/VOL | RL = 1M | VCC - VOH | 0.23 | 2.5 | mV |
VOL - VEE | 0.22 | 2.5 | ||||
RL = 10k | VCC - VOH | 12 | 50 | |||
VOL - VEE | 7 | 50 | ||||
RL = 5k | VCC - VOH | 100 | 100 | |||
VOL - VEE | 100 | 100 | ||||
Gain-Bandwidth Product | GBW | 230 | kHz | |||
Slew Rate | SR | VOUT = 4V step | 90 | V/ms | ||
Settling Time (to 0.01%) | VOUT = 4V step | 69 | µs | |||
Input Voltage Noise Density | en | f = 5kHz | 110 | nV/Hz | ||
Input Noise Current Density | f = 5kHz | 1.1 | fA/Hz | |||
Capacitive Load Stability | CLOAD | No sustained oscillations, AV = +1V/V | 100 | pF | ||
Power-Up Time | Output settling to 1% | 10 | ms |
Note 1: All devices are 100% production tested at TA = +25°C. All temperature limits are guaranteed by design.
Note 2: Guaranteed by design.
Note 3: The input common-mode range for IN_+ is guaranteed by a functional test. A similar test is done on the IN_- input. See the
Applications Information section for more information on the input voltage range of the GainAmps.
Note 4: For AV = -0.5V/V and AV = -0.25V/V, the output voltage swing may be limited by the input voltage range.
Note 5: Includes noise from on-chip resistors.
Note 6: The gain accuracy test is performed with the GainAmps in the noninverting configuration. The output voltage swing is limit- ed by the input voltage range for certain gains and supply voltage conditions. For situations where the output voltage swing is limited by the valid input range, the output limits are adjusted accordingly.
(VCC = +5.0V, RL = 100k to VCC/2, TA = +25°C, unless otherwise noted.)
MAX4074/MAX4075
SMALL-SIGNAL GAIN vs. FREQUENCY
4
SMALL-SIGNAL GAIN vs. FREQUENCY
MAX4074-8 tocc1-2
4
SMALL-SIGNAL GAIN vs. FREQUENCY
MAX4074-8 tocc3-4
MAX4074-8 tocc5-6
4
3 VOUT = 100mVp-p 3
2 2
1 1
VOUT = 100mVp-p 3
2
1
VOUT = 100mVp-p
GAIN (dB)
0
-1 AV = +2.25V/V
-2
-3
-4
-5
-6
AV = +1.25V/V 0
GAIN (dB)
-1
-2
-3
-4
-5
-6
AV = +4V/V
AV = +2.5V/V
0
GAIN (dB)
-1
-2 AV = +9V/V
-3
-4
-5
-6
AV = +5V/V
1k 10k
100k 1M
1k 10k 100k 1M
1k 10k 100k 1M
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQUENCY (Hz)
(VCC = +5.0V, RL = 100k to VCC/2, TA = +25°C, unless otherwise noted.)
MAX4074/MAX4075
SMALL-SIGNAL GAIN vs. FREQUENCY
4
SMALL-SIGNAL GAIN vs. FREQUENCY
MAX4074-8 toc04
4
SMALL-SIGNAL GAIN vs. FREQUENCY
MAX4074-8 toc05
MAX4074-8 toc06
4
3 VOUT = 100mVp-p 3
2 2
1 1
GAIN (dB)
GAIN (dB)
0 0
VOUT = 100mVp-p 3
2
1
GAIN (dB)
0
VOUT = 100mVp-p
-1
-2 AV = +21V/V
-3
-4
-5
-6
1k 10k
AV = +10V/V
100k 1M
-1
-2 AV = +50V/V
-3
-4
-5
-6
1k 10k
AV = +25V/V
100k 1M
-1
-2 AV = +101V/V
-3
-4
-5
-6
1k 10k
AV = +51V/V
100k 1M
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQUENCY (Hz)
LARGE-SIGNAL GAIN vs. FREQUENCY
4
LARGE-SIGNAL GAIN vs. FREQUENCY
MAX4074-8 toc07
4
LARGE-SIGNAL GAIN vs. FREQUENCY
MAX4074-8 toc08
MAX4074-8 toc09
4
3 VOUT = 1Vp-p 3
2 2
1 1
VOUT = 1Vp-p 3
2
1
VOUT = 1Vp-p
GAIN (dB)
0
-1
-2 AV = +2.25V/V
-3
-4
-5
-6
1k 10k
AV = +1.25V/V 0
GAIN (dB)
-1
-2
-3
-4
-5
-6
100k 1M 1k
AV = +4V/V
10k
AV = +2.5V/V
100k 1M
0
GAIN (dB)
-1
-2 AV = +9V/V
-3
-4
-5
-6
1k 10k
AV = +5V/V
100k 1M
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQUENCY (Hz)
LARGE-SIGNAL GAIN vs. FREQUENCY
4
LARGE-SIGNAL GAIN vs. FREQUENCY
MAX4074-8 toc10
4
LARGE-SIGNAL GAIN vs. FREQUENCY
MAX4074-8 toc11
MAX4074-8 toc12
4
3 VOUT = 1Vp-p 3
2 2
1 1
GAIN (dB)
GAIN (dB)
0 0
VOUT = 1Vp-p 3
2
1
AV = +25V/V
GAIN (dB)
0
VOUT = 1Vp-p
-1
-2 AV = +21V/V
-3
-4
-5
-6
1k 10k
AV = +10V/V -1
-2
-3
-4
-5
-6
100k 1M 1k
AV = +50V/
V
10k
100k 1M
-1
-2 AV = +101V/V
-3
-4
-5
-6
1k 10k
AV = +51V/V
100k 1M
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQUENCY (Hz)
THD (dB)
(VCC = +5.0V, RL = 100k to VCC/2, TA = +25°C, unless otherwise noted.)
MAX4074/MAX4075
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
TOTAL HARMONIC DISTORTION vs. FREQUENCY
VOUT = 1Vp-p
AV = +3V/V
AV = +10V/V
AV = +1.25V/V
0
MAX4074-8 toc25
-10
-20
-30
THD (dB)
-40
-50
-60
-70
-80
-90
-100
TOTAL HARMONIC DISTORTION vs. FREQUENCY
VOUT = 1Vp-p
V = +51V/V
A
AV = +25V/V
-20
MAX4074-8 toc26
-30
-40
THD (dB)
-50
-60
-70
-80
-90
TOTAL HARMONIC DISTORTION vs. OUTPUT VOLTAGE SWING
MAX4074-8 toc27
f = 10kHz
AV = +3V/V AV = +10V/V
AV = +1.25V/V
MAX4074-8 toc29
100 1k
10k
100k
100 1k
10k
100k
0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
FREQUENCY (Hz)
-20
-30
-40
THD (dB)
-50
-60
-70
TOTAL HARMONIC DISTORTION vs. OUTPUT VOLTAGE SWING
f = 10kHz
AV = +51V/V AV = +25V/V
FREQUENCY (Hz)
MAX4074-8 toc28
1000
VOLTAGE NOISE (nV/Hz)
100
VOLTAGE NOISE DENSITY vs. FREQUENCY
A
V = +3V/V AV = +10V/V
AV = +1.25V/V
VOLTAGE SWING (Vp-p)
-80
-90
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
VOLTAGE SWING (Vp-p)
10
1 10 100
1k 10k 100k FREQUENCY (Hz)
1M 10M
1000
VOLTAGE NOISE (nV/Hz)
100
VOLTAGE NOISE DENSITY vs. FREQUENCY
AV = +25V/V
V
= +51V/
AV
CURRENT NOISE DENSITY vs. FREQUENCY
MAX4074-8 toc30
CURRENT NOISE DENSITY (fA/Hz)
MAX4074 TOC31
10
1
10
1 10 100
1k 10k 100k FREQUENCY (Hz)
1M 10M
0.1
1
10 100
1k 10k 100k 1M FREQUENCY (Hz)
10M
(VCC = +5.0V, RL = 100k to VCC/2, TA = +25°C, unless otherwise noted.)
MAX4074/MAX4075
SMALL-SIGNAL PULSE RESPONSE LARGE-SIGNAL PULSE RESPONSE
INPUT
OUTPUT
50mV/div AV = +1.25V/V
OUTPUT
50mV/div AV = +3V/V
OUTPUT
50mV/div AV = +5V/V
OUTPUT
50mV/div AV = +10V/V
OUTPUT
50mV/div AV = +25V/V
OUTPUT
50mV/div AV = +51V/V
INPUT
MAX4074 TOC36
MAX4074 TOC35
OUTPUT
500mV/div AV = +1.25V/V
OUTPUT
500mV/div AV = +3V/V
OUTPUT
500mV/div AV = +5V/V
OUTPUT
500mV/div AV = +10V/V
OUTPUT
500mV/div AV = +25V/V
OUTPUT
500mV/div AV = +51V/V
10s/div 10s/div
PSR (dB)
(VCC = +5.0V, RL = 100k to VCC/2, TA = +25°C, unless otherwise noted.)
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
POWER-SUPPLY REJECTION vs. FREQUENCY
MAX4074 TOC32
1k
OUTPUT IMPEDANCE ()
100
10
1
0.1
OUTPUT IMPEDANCE vs. FREQUENCY
MAX4074TOC33
300
250
OUTPUT SWING (mV)
200
150
100
50
0
OUTPUT VOLTAGE SWING vs. RLOAD
MAX4074 TOC34
VCC - VOH
VOL - VEE
100 1k
10k
100k
100 1k 10k 100k 1M
1 10 100
FREQUENCY (Hz)
FREQUENCY (Hz)
RLOAD (k)
INPUT OFFSET VOLTAGE vs. TEMPERATURE
MAX4074/5-toc35
100
INPUT OFFSET VOLTAGE (V)
75
50
25
600
500
INPUT BIAS CURRENT (pA)
400
300
INPUT BIAS CURRENT vs. TEMPERATURE
MAX4074/5-toc36
VCC - VEE = 5.5V MAX4074/4075
VCC - VEE = 2.5V
0
-25
-50
VCC - VEE = 5.5V
VCC - VEE = 2.5V
200
100
0
VCC
- VEE
= 5.5V
-75
-100
-100
-200
MAX4076/77/78
VCC - VEE = 2.5V
-50
-35 -20
-5 10
25 40 55 70 85
-45
-30 -15
0 15
30 45 60 75 90
175
150
TEMPERATURE (°C)
VOH AND VOL vs. TEMPERATURE (VCC - VEE = 2.5V)
MAX4074/5-toc37
450
400
VOH AND VOL vs. TEMPERATURE (VCC - VEE = 5.5V)
TEMPERATURE (°C)
SUPPLY CURRENT vs. TEMPERATURE
MAX4074/5-toc38
MAX4074/5-toc39
40.0
125
100
VOLTAGE (mV)
75
50
VOH RL = 1k
V
R = 100k
350
300
VOLTAGE (mV)
250
200
VOH RL = 1k
SUPPLY CURRENT (A)
37.5
VCC - VEE = 5.5V VCC - VEE = 4.0V
25 VOH RL = 10k
OH L
150
100
V R = 100k
35.0
VCC - VEE = 3.0V
0
-25
VOL RL = 10k
V R = 100k
50 VOH RL = 10k 0
OH L
32.5
V - V
= 2.5V
-50
-75
-100
VOL RL = 1k
OL L
-50
-100
-150
VOL RL = 10k VOL RL = 1k
VOL RL = 100k
30.0
CC EE
-50
-35 -20
-5 10
25 40 55 70 85
-50
-35 -20
-5 10
25 40 55 70 85
-50
-35 -20
-5 10
25 40 55 70 85
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
(VCC = +5.0V, RL = 100k to VCC/2, TA = +25°C, unless otherwise noted.)
MAX4076/MAX4077/MAX4078
SMALL-SIGNAL GAIN vs. FREQUENCY
4
3
2
1
GAIN (dB)
0
-1
-2
-3
-4
-5
MAX4076-8 toc3
-6
LARGE-SIGNAL GAIN vs. FREQUENCY
MAX4076/7/8 toc1
4
3
2
1
GAIN (dB)
0
-1
-2
-3
-4
-5
-6
1k
MAX4076- 8 toc2
VOLTAGE NOISE (nV/Hz)
100
10
VOLTAGE NOISE vs. FREQUENCY
1k 10k 100k 1M 10M FREQUENCY (Hz)
1k 10k 100k 1M 10M FREQUENCY (Hz)
1 10 100 1k 10k 100k 1M 10M FREQUENCY (Hz)
100
CURRENT NOISE (pA/Hz)
10
1
0.1
MAX4076-8 toc6
CURRENT NOISE vs. FREQUENCY
MAX4076-8 toc4
-40
-50
THD (dB)
-60
-70
-80
-90
TOTAL HARMONIC DISTORTION vs. FREQUENCY
AV = +1V/V
-80
MAX4076-8 toc5
-85
-90
CROSSTALK (dB)
-95
-100
-105
-110
-115
-120
-125
-130
MAX4077 CROSSTALK vs. FREQUENCY
1 10 100
1k 10k 100k
1M 10M
100 1k
10k
100k
1k 10k 100k 1M
-60
-65
-70
CROSSTALK (dB)
-75
-80
-85
-90
-95
-100
-105
-110
FREQUENCY (Hz)
MAX4078
ALL HOSTILE CROSSTALK vs. FREQUENCY
MAX4076-8 toc7
THREE AMPLIFIERS DRIVEN, ONE OUTPUT MEASURED.
120
80
40
GAIN (dB)
0
-40
-80
-120
-160
-200
FREQUENCY (Hz)
GAIN AND PHASE vs. FREQUENCY
GAI
N
PHASE
MAX4076-8 toc8 270
180
90
0
-90
-180
-270
-360
-450
-10
-20
-30
PHASE (degrees)
CMR (dB)
-40
-50
-60
-70
-80
-90
-100
FREQUENCY (Hz)
MAX4076-8 toc9
COMMON-MODE REJECTION vs. FREQUENCY
1k 10k 100k 1M FREQUENCY (Hz)
1 10 100
1k 10k 100k 1M FREQUENCY (Hz)
10M
1 10 100
1k 10k 100k 1M FREQUENCY (Hz)
10M
PIN | NAME | FUNCTION | |||
MAX4074/MAX4076 | MAX4075 MAX4077 | MAX4078 | |||
SOT23 | SO | µMAX/SO | SO/TSSOP | ||
1 | 6 | 1, 7 | 1, 7, 8, 14 | OUT_ | Amplifier Output |
2 | 4 | 4 | 11 | VEE | Negative Supply or Ground |
3 | 3 | 3, 5 | 3, 5, 10, 12 | IN_+ | Noninverting Amplifier Input |
4 | 2 | 2, 6 | 2, 6, 9, 13 | IN_- | Inverting Amplifier Input |
5 | 7 | 8 | 4 | VCC | Positive Supply |
— | 1, 5, 8 | — | — | N.C. | No Connection. Not internally connected. |
Maxim’s GainAmp fixed-gain amplifiers combine a low- cost rail-to-rail op amp with internal gain-setting resis- tors. Factory-trimmed on-chip resistors provide 0.1% gain accuracy while decreasing design size, cost, and layout. There are two versions in this amplifier family: single/dual/quad open-loop, unity-gain-stable devices (MAX4076/MAX4077/MAX4078), and single/dual fixed- gain devices (MAX4074/MAX4075). All amplifiers fea- ture rail-to-rail outputs and drive a 10k load while maintaining excellent DC accuracy.
Open-Loop Op Amps The single/dual/quad MAX4076/MAX4077/MAX4078 are low-power, open-loop op amps with rail-to-rail outputs. These devices are compensated for unity-gain stability and feature a GBW product of 230kHz. The common- mode range extends from 150mV below the negative rail to within 1.2V of the positive rail. These high-perfor- mance op amps serve as the core for this family of GainAmp fixed-gain amplifiers. Although the -3dB band- width will not correspond to that of a fixed-gain amplifier in higher gain configurations, these open-loop op amps can be used to prototype designs.
VCC A = -RF V RG RG RF AV = 1 + RF IN- RG VEE OUT IN+ |
Figure 1. Internal Gain-Setting Resistors
Internal Gain-Setting Resistors Maxim’s proprietary laser trimming techniques allow RF/RG values (Figure 1) that produce many different gain configurations. These GainAmp fixed-gain ampli- fiers feature a negative-feedback resistor network that is laser trimmed to provide a gain-setting feedback ratio (RF/RG) with 0.1% typical accuracy. The standard op amp pinouts allow the GainAmp fixed-gain ampli- fiers to plug directly into existing board designs, easily replacing op amps-plus-resistor gain blocks.
GainAmp Bandwidth GainAmp fixed-gain amplifiers feature factory-trimmed precision resistors to provide fixed inverting gains from
-0.25V/V to -100V/V or noninverting gains from +1.25V/V to +101V/V. The op amp core is decompensated strate- gically over the gain-set options to maximize band-
the protection of sensitive input stage circuitry. Current through the clamp diodes is limited by a 5k resistor at the noninverting input, and by RG at the inverting input. An IN+ or IN- fault voltage as high as ±17V causes less than 3.5mA to flow through the input pin, protecting both the GainAmp and the signal source from damage.
Applications Information
width. Open-loop decompensation increases GBW product, ensuring that usable bandwidth is maintained
with increasing closed-loop gains. A GainAmp with a fixed gain of AV = +25V/V has a -3dB bandwidth of 120kHz. By comparison, a unity-gain-stable op amp con- figured for AV = +25V/V would yield a -3dB bandwidth of only 8kHz. Decompensation is performed at five inter- mediate gain sets, as shown in the Gain Selector Guide.
High-Voltage (±17V) Input Fault Protection
The MAX4074/MAX4075 family includes ±17V input fault protection. For normal operation, see the input voltage range specification in the Electrical Character- istics. Overdriven inputs up to ±17V will not cause out- put phase reversal. A back-to-back SCR structure at the input pins allows either input to safely swing ±17V relative to VEE (Figure 2). Additionally, the internal op amp inputs are diode clamped to both supply rails for
GainAmp fixed-gain amplifiers offer a precision, fixed- gain amplifier in a small package that can be used in a variety of circuit board designs. GainAmp fixed-gain amplifiers can be used in many op amp circuits that use resistive negative feedback to set gain, and do not require other connections to the op amp inverting input. Both inverting and noninverting op amp configurations can be implemented easily using a GainAmp.
GainAmp Input Voltage Range The MAX4074/MAX4075 combine both an op amp and gain-setting feedback resistors on the same IC. The inverting input voltage range is different from the nonin- verting input voltage range because the inverting input pin is connected to the RG input series resistor. Just as with a discrete design, take care not to saturate the inputs/output of the core op amp to avoid signal distor- tions or clipping.
RF
IN-
RG
17V SCR
OUT
VEE
VCC
IN+
5k
17V SCR
VEE
MAX4074 MAX4075
VEE
NOTE: INPUT STAGE PROTECTION INCLUDES TWO 17V SCRs AND TWO DIODES AT THE INPUT STAGE.
Figure 2. Input Protection
GainAmp Signal Coupling and Configurations
Common op amp configurations include both noninvert- ing and inverting amplifiers. Figures 3–6 show various single- and dual-supply circuit configurations. In single- supply systems, use a resistor-divider to bias the nonin- verting input. A lowpass filter capacitor from the op amp input to ground (Figure 5) prevents high-frequency power-supply noise from coupling into the op amp input. Dual-supply systems can have ground-referenced sig- nals DC-coupled into the inverting or noninverting inputs.
Supply Bypassing and Board Layout All devices in this GainAmp family operate from a +2.5V to +5.5V single supply or from ±1.25V to ±2.75V dual supplies. For single-supply operation, bypass the power supply with a 0.1µF capacitor to ground. For dual sup- plies, bypass each supply to ground. Bypass with capacitors as close to the device as possible to mini- mize lead inductance and noise. A printed circuit board with a low-inductance ground plane is recommended.
Capacitive-Load Stability Driving large capacitive loads can cause instability in most low-power, rail-to-rail output amplifiers. The fixed- gain amplifiers of this GainAmp family are stable with capacitive loads up to 100pF. Stability with higher capacitive loads can be improved by adding an isola- tion resistor in series with the op amp output, as shown in Figure 7. This resistor improves the circuit’s phase margin by isolating the load capacitor from the amplifi- er’s output. In Figure 8, a 220pF capacitor is driven with a 100 isolation resistor exhibiting some overshoot but no oscillation. Figures 9 and 10 show the typical small- signal pulse responses of GainAmp fixed-gain ampli- fiers with 47pF and 100pF capacitive loads and no isolation resistor
VCC MAX4074 VCC VIN RG RF VOUT = -RF (VIN) RG |
Figure 3. Single-Supply, DC-Coupled Inverting Amplifier with Negative Input Voltage
MAX4074 VCC VOUT = - VIN ( RF ) RG VEE VIN RG RF |
Figure 4. Dual-Supply, DC-Coupled Inverting Amplifier
VCC MAX4074 VCC VOUT = VCC - VIN ( RF ) 0.1F 2 RG VIN RG RF |
Figure 5. Single-Supply, AC-Coupled Inverting Amplifier
MAX4074 VCC VIN VOUT = VIN (1+ RF ) RG VEE RF RG |
Figure 6. Dual-Supply, DC-Coupled Noninverting Amplifier
MAX4074 RG RF VCC RISO OUTPUT INPUT CL RL VEE |
INPUT AV = +5V/V OUTPUT 50mV/div AV = +5V/V OUTPUT 500mV/div |
Figure 7. Dual-Supply, Capacitive-Load-Driving Circuit
Figure 8. Small-Signal/Large-Signal Transient Response with Excessive Capacitive Load and Isolation Resistor
INPUT OUTPUT 50mV/div AV = +1.25V/V OUTPUT 50mV/div AV = +3V/V OUTPUT 50mV/div AV = +5V/V OUTPUT 50mV/div AV = +10V/V OUTPUT 50mV/div AV = +25V/V OUTPUT 50mV/div AV = +51V/V 10s/div |
INPUT OUTPUT 50mV/div AV = +1.25V/V OUTPUT 50mV/div AV = +3V/V OUTPUT 50mV/div AV = +5V/V OUTPUT 50mV/div AV = +10V/V OUTPUT 50mV/div AV = +25V/V OUTPUT 50mV/div AV = +51V/V 10s/div |
Figure 9. GainAmp Small-Signal Pulse Response (CL = 340pF, RL = 100k)
Figure 10. GainAmp Small-Signal Pulse Response (CL = 940pF, RL = 100k)
GAIN CODE | INVERTING GAIN (V/V) | NONINVERTING GAIN (V/V) | -3dB BW (kHz) | TOP MARK |
AB | 0.25 | 1.25 | 200 | ADJB |
AC | 0.5 | 1.5 | 136 | ADJC |
AD | 1 | 2 | 102 | ADJD |
AE | 1.25 | 2.25 | 70 | ADJE |
AF | 1.5 | 2.5 | 180 | ADJF |
AG | 2 | 3 | 135 | ADJG |
AH | 2.5 | 3.5 | 116 | ADJH |
AJ | 3 | 4 | 90 | ADJI |
AK | 4 | 5 | 80 | ADJJ |
AL | 5 | 6 | 71 | ADJK |
AM | 6 | 7 | 61 | ADJL |
AN | 8 | 9 | 50 | ADJM |
AO | 9 | 10 | 90 | ADJN |
BA | 10 | 11 | 79 | ADJO |
BB | 12.5 | 13.5 | 64 | ADJP |
BC | 15 | 16 | 54 | ADJQ |
BD | 20 | 21 | 40 | ADJR |
BE | 24 | 25 | 120 | ADJS |
BF | 25 | 26 | 106 | ADJT |
BG | 30 | 31 | 89 | ADJU |
BH | 40 | 41 | 67 | ADJV |
BJ | 49 | 50 | 50 | ADJW |
BK | 50 | 51 | 82 | ADJX |
BL | 60 | 61 | 66 | ADJY |
BM | 79 | 80 | 50 | ADJZ |
BN | 99 | 100 | 40 | ADKA |
CA | 100 | 101 | 38 | ADKB |
Note: Bold indicates preferred gains. These gain versions are available as samples and in small quantities.
12 IND+
INA+ 3
+
RF
+
7 OUTB
7 OUTB INA- 2
RG
INA- 2
13 IND-
+
INA- 2
-
-
+
-
TOP VIEW
MAX4074
MAX4076
MAX4076
N.C. 1
8 N.C.
OUT 1
5 VCC
N.C. 1
8 N.C.
IN- 2
7 VCC
VEE 2
+
IN- 2
7 VCC
IN+ 3
6 OUT
IN+ 3
4 IN-
IN+ 3
6 OUT
VEE 4
5 N.C.
SOT23-5
VEE 4
5 N.C.
SO SO
MAX4075
MAX4077
MAX4078
OUTA 1
RF
8 VCC
OUTA 1
8 VCC OUTA 1
14 OUTD
INA+ 3
RG
6 INB-
INA+ 3
6
INB-
VCC 4
11 VEE
VEE 4
5 INB+
VEE 4
5 INB+ INB+ 5
10 INC+
MAX/SO MAX/SO INB- 6 9 INC-
OUTB 7
8 OUTC
SO/TSSOP
PART | TEMP. RANGE | PIN- PACKAGE | TOP MARK |
MAX4075__EUA | -40°C to +70°C | 8 µMAX | — |
MAX4075__ESA | -40°C to +70°C | 8 SO | — |
MAX4076EUK-T | -40°C to +70°C | 5 SOT23-5 | ** |
MAX4076ESA | -40°C to +70°C | 8 SO | — |
MAX4077EUA | -40°C to +70°C | 8 µMAX | — |
MAX4077ESA | -40°C to +70°C | 8 SO | — |
MAX4078EUD | -40°C to +70°C | 14 TSSOP | — |
MAX4078ESD | -40°C to +70°C | 14 SO | — |
Note: Insert the desired gain code in the blank to complete the part number (see the Gain Selector Guide).
**See the Gain Selector Guide for a list of preferred gains and top marks.
TRANSISTOR COUNTS
MAX4074: 180 MAX4077: 340
MAX4075: 360 MAX4078: 332
MAX4076: 180
+5V VCC VCC VCC 0.1F IN+ MAX4074 0.1F OUT INPUT IN- RG RF 0.1F VEE |
Typical Operating Circuit
SOT5L.EPS
TSSOP.EPS
8LUMAXD.EPS
SOICN.EPS
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.
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