19-1526; Rev 1; 10/99


Micropower, SOT23, Rail-to-Rail,

Fixed-Gain, GainAmp/Open-Loop Op Amps

MAX4074–MAX4078

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.

Functional Diagrams


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.


MAX4074–MAX4078

ABSOLUTE MAXIMUM RATINGS

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.


ELECTRICAL CHARACTERISTICS—MAX4074/MAX4075

(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


MAX4074–MAX4078

ELECTRICAL CHARACTERISTICS—MAX4074/MAX4075 (continued)

(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


ELECTRICAL CHARACTERISTICS—MAX4076/MAX4077/MAX4078

(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



MAX4074–MAX4078

ELECTRICAL CHARACTERISTICS—MAX4076/MAX4077/MAX4078 (continued)

(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.


Typical Operating Characteristics

(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)


MAX4074–MAX4078

Typical Operating Characteristics

(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)


MAX4074–MAX4078

THD (dB)

Typical Operating Characteristics (continued)

(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


MAX4074–MAX4078

Typical Operating Characteristics (continued)

(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


MAX4074–MAX4078

PSR (dB)

Typical Operating Characteristics (continued)

(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)


MAX4074–MAX4078

Typical Operating Characteristics (continued)

(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


MAX4074–MAX4078

Pin Description


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.


Detailed Description

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.


MAX4074–MAX4078

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


MAX4074–MAX4078

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

MAX4074–MAX4078

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

MAX4074–MAX4078

Figure 9. GainAmp Small-Signal Pulse Response (CL = 340pF, RL = 100k)

Figure 10. GainAmp Small-Signal Pulse Response (CL = 940pF, RL = 100k)


MAX4074–MAX4078

Gain Selector Guide


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

-

-

+

MAX4074–MAX4078

-

Pin Configurations/Functional Diagrams


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


Ordering Information (continued)


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.

Chip Information

MAX4074–MAX4078

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


MAX4074–MAX4078

SOT5L.EPS

Package Information











MAX4074–MAX4078

TSSOP.EPS

Package Information (continued)












MAX4074–MAX4078

8LUMAXD.EPS

Package Information (continued)



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.

20 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.

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Authorized Distributor


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