19-1407; Rev 3; 8/99


SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps


MAX4174/5, MAX4274/5, MAX4281/2/4

General Description Features

The MAX4174/MAX4175/MAX4274/MAX4275 Gain-

Amp™ family combines a low-cost Rail-to-Rail® op amp with precision internal gain-setting resistors and VCC / 2 biasing. 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 only 300µA. GainAmp amplifiers are optimally compensated for each gain version, achieving exceptional GBW prod- ucts up to 23MHz (A V = +25V/V to +101V/V). High-volt- age fault protection withstands ±17V at either input without excessive current draw.

Three versions are available in this amplifier family: single/ dual/quad open-loop, unity-gain stable (MAX4281/ MAX4282/MAX4284); single/dual fixed gain (MAX4174/ MAX4274); and single/dual fixed gain plus internal VCC / 2 bias at the noninverting input (MAX4175/ MAX4275), which simplifies input biasing in single-supply designs. The input common-mode voltage range of the

open-loop amplifiers extends from 150mV below the Ordering Information

PART*

TEMP. RANGE

PIN- PACKAGE

TOP MARK

MAX4174_EUK-T

-40°C to +85°C

5 SOT23-5

††

MAX4175_EUK-T

-40°C to +85°C

5 SOT23-5

††

negative supply to within 1.2V of the positive supply. The outputs can swing rail-to-rail and drive a 1k load while maintaining excellent DC accuracy. The amplifier is stable for capacitive loads up to 470pF.

Applications

Portable Instruments Smart-Card Readers

Instruments, Terminals, Infrared Receivers for and Bar-Code Readers Remote Controls

Keyless Entry Low-Side Current-Sense

Photodiode Preamps Amplifiers


Ordering Information continued at end of data sheet.

* Insert the desired gain code (from the Gain Selection Guide) in the blank to complete the part number.

†† Refer to the Gain Selection Guide for a list of preferred gains and SOT Top Marks.


Selector Guide appears at end of data sheet.

IN+

RB MAX4175

VEE 2

+

RF

5 VCC

Pin Configurations Typical Operating Circuit

TOP VIEW

+5V


OUT 1

MAX4174

VCC

VCC

0.1F


IN+ 3

4 IN-

INPUT

IN-

VEE


SOT23-5

Pin Configurations continued at end of data sheet.

0.1F

RG

RF


VEE

OUT

RB

0.1F

RG

GainAmp is a trademark of Maxim Integrated Products. Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd.


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.


MAX4174/5, MAX4274/5, MAX4281/2/4

ABSOLUTE MAXIMUM RATINGS

Supply Voltage (VCC to VEE) ....................................-0.3V to +6V

Voltage Inputs (IN_)

MAX4281/4282/4284.....................(VEE - 0.3V) to (VCC + 0.3V) MAX4174/4175/4274/4275 (with respect to GND) ...........±17V

Output Short-Circuit Duration (OUT_).....................................Continuous to Either VEE or VCC

Continuous Power Dissipation (TA = +70°C)

5-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 4.1mW/°C above +70°C) ............330mW

14-Pin SO (derate 8.3mW/°C above +70°C)...............667mW

16-Pin QSOP (derate 8.3mW/°C above +70°C)..........667mW Operating Temperature Range ...........................-40°C to +85°C

Maximum 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 rating s only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specificatio ns is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.


ELECTRICAL CHARACTERISTICS—MAX4174/MAX4175/MAX4274/MAX4275 Fixed-Gain

Amplifiers

(VCC = +2.5V to +5.5V, VEE = 0, VIN+ = VIN- = VCC / 2, RL to VCC / 2, RL = open, 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 tests

2.5


5.5

V


Supply Current (per Amplifier)


ICC

MAX4174/MAX4274

VCC = 3V


300

460


µA

VCC = 5V


330

510

MAX4175/MAX4275,

includes VCC / 2 bias resistors

VCC = 3V


320

480

VCC = 5V


355

530

Input Offset Voltage

VOS

RL = 100k


±0.5

±2.5

mV

Input Offset Voltage Drift



±5

µV/°C

Input Bias Current

IBIAS

IN_+, MAX4174/MAX4274 (Note 2)


±0.05

±10

nA

Inverting Input Resistance


AV < 25V/V

150

k

AV > 25V/V

40

Noninverting Input Resistance


MAX4174/MAX4274

1000

M

MAX4175/MAX4275

75

k

IN_+ Bias Voltage


MAX4175/MAX4275, VIN+ = VIN-

VCC / 2

- 0.25


VCC / 2

+ 0.25

V

IN_+ Input Voltage Range


Guaranteed by functional test (Note 3)

VEE


VCC - 1.2

V

IN_- Input Voltage Range


Guaranteed by functional test

VEE


VCC

V

Power-Supply Rejection Ratio

PSRR

VCC = 2.5V to 5.5V

70

90


dB

Closed-Loop Output Impedance

ROUT


0.02

Short-Circuit Current


Shorted to VEE

10

mA

Shorted to VCC

65


Output Voltage Swing (Note 4)


VOH/VOL

RL = 100k

VCC - VOH


2

8


mV

VOL - VEE


2

8

RL = 1k

VCC - VOH


150

250

VOL - VEE


60

150


MAX4174/5, MAX4274/5, MAX4281/2/4

ELECTRICAL CHARACTERISTICS—MAX4174/MAX4175/MAX4274/MAX4275 Fixed-Gain

Amplifiers (continued)

(VCC = +2.5V to +5.5V, VEE = 0, VIN+ = VIN- = VCC / 2, RL to VCC / 2, RL = open, TA = TMIN to TMAX, unless otherwise noted. Typical

PARAMETER

SYMBOL

CONDITIONS

MIN TYP MAX

UNITS

Power-Up Time


Output settling to 1%

1

ms

Slew Rate

SR

VCC = 5V, VOUT = 4V step

0.7

V/µs

Settling Time to Within 0.01%


VCC = 5V, VOUT = 4V step

7

µs

Input Noise Voltage Density

en

f = 10kHz (Note 5)

90

nV/Hz

Input Noise Current Density

in

f = 10kHz

4

fA/Hz

Capacitive Load Stability

CLOAD

No sustained oscillations

470

pF

DC Gain Accuracy


(VEE + 25mV) < VOUT < (VCC - 25mV),

RL = 100k (Note 6)

0.1 0.5

%


-3dB Bandwidth


BW-3dB

Gain = +1.25V/V

1700


kHz

Gain = +3V/V

970

Gain = +5V/V

970

Gain = +10V/V

640

Gain = +25V/V

590

Gain = +51V/V

330


ELECTRICAL CHARACTERISTICS—MAX4281/MAX4282/MAX4284 Open-Loop Op Amps

(VCC = +2.5V to +5.5V, VEE = 0, VIN+ = VIN- = VCC / 2, RL to VCC / 2, RL = open, 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 tests

2.5 5.5

V

Supply Current (per Amplifier)

ICC

VCC = 3V

290 450

µA

VCC = 5V

320 500

µA

Input Offset Voltage

VOS

RL = 100k

±0.5 ±2

mV

Input Offset Voltage Drift



±5

µV/°C

Input Bias Current

IBIAS


±0.05 ±10

nA

Input Offset Current

IOS


±10 ±1000

pA

Input Resistance

RIN

Differential or common mode

1000

M

Input Capacitance

CIN


2.5

pF

Common-Mode Input Voltage Range

CMVR

Guaranteed by CMRR test

VEE - 0.15 VCC - 1.2

V

Common-Mode Rejection Ratio

CMRR

VEE - 0.15V VCM VCC - 1.2V

60 90

dB

Power-Supply Rejection Ratio

PSRR

VCC = 2.5V to 5.5V

70 90

dB

Closed-Loop Output Impedance

ROUT

AV = 1V/V

0.02


MAX4174/5, MAX4274/5, MAX4281/2/4

ELECTRICAL CHARACTERISTICS—MAX4281/MAX4282/MAX4284 Open-Loop Op Amps

(continued)

(VCC = +2.5V to +5.5V, VEE = 0, VIN+ = VIN- = VCC / 2, RL to VCC / 2, RL = open, 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

Short-Circuit Current


Shorted to VEE

10

mA

Shorted to VCC

65

mA

Large-Signal Voltage Gain

AVOL

VEE + 0.05V < VOUT < VCC - 0.1V, RL = 100k

90 120

dB

VEE + 0.25V < VOUT < VCC - 0.3V, RL = 1k

80 100

dB


Output Voltage Swing


VOH/VOL

RL = 100k

VCC - VOH

2 8


mV

VOL - VEE

2 8

RL = 1k

VCC - VOH

160 250

VOL - VEE

60 100

Gain Bandwidth Product

GBW


2

MHz

Slew Rate

SR

VCC = 5V, VOUT = 4V step

0.7

V/µs

Settling Time to within 0.01%


VCC = 5V, VOUT = 4V step

7

µs

Input Noise Voltage Density

en

f = 10kHz

60

nV/Hz

Input Noise Current Density

in

f = 10kHz

1.8

fA/Hz

Capacitive Load Stability

CLOAD

No sustained oscillations, AV = 1V/V

470

pF

Power-Up Time


Output settling to 1%

1

ms

Note 1: MAX4174/MAX4175/MAX4281 and MAX4274/MAX4275/MAX4282 and MAX4284 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 GainAmp. Note 4: For AV = -0.5V/V and AV = -0.25V/V, the output voltage swing is limited by the input voltage range. Note 5: Includes noise from on-chip resistors.

Note 6: The gain accuracy test is performed with the GainAmp in noninverting configuration. The output voltage swing is limited by the input voltage range for certain gains and supply voltage conditions. For situations where the output voltage swing is lim- ited by the valid input range, the output limits are adjusted accordingly.


Typical Operating Characteristics

(VCC = +5V, RL = 100k to VCC / 2, small-signal VOUT = 100mVp-p, large-signal VOUT = 1Vp-p, TA = +25°C, unless otherwise noted.)


LARGE-SIGNAL GAIN vs. FREQUENCY




































AV = +1.25V/V





































































AV = +2.25V/V



































4

3

NORMALIZED GAIN (dB)

2

1

0

-1

-2

-3

-4

-5

-6

LARGE-SIGNAL GAIN vs. FREQUENCY

MAX4174 TOC01





































AV = +2.5V/V







































AV = +4V/V



































































4

3

NORMALIZED GAIN (dB)

2

1

0

-1

-2

-3

-4

-5

-6

LARGE-SIGNAL GAIN vs. FREQUENCY

MAX4174 TOC02

MAX4174 TOC03

4

3

NORMALIZED GAIN (dB)

2 AV = +5V/V

1

0

-1

-2 AV = +9V/V

-3

-4

-5

-6

1k 10k

100k 1M

10M

1k 10k

100k 1M

10M

1k 10k

100k 1M

10M


MAX4174/5, MAX4274/5, MAX4281/2/4

Typical Operating Characteristics (continued)

(VCC = +5V, RL = 100k to VCC / 2, small-signal VOUT = 100mVp-p, large-signal VOUT = 1Vp-p, TA = +25°C, unless otherwise noted.)

MAX4174/MAX4175

LARGE-SIGNAL GAIN vs. FREQUENCY

4

3

NORMALIZED GAIN (dB)

2 AV = +10V/V

1

0

-1

/V

+2

=

V

A

-2 1V

-3

-4

-5

-6

LARGE-SIGNAL GAIN vs. FREQUENCY

MAX4174 TOC04

4

3

NORMALIZED GAIN (dB)

2 AV = +25V/V

1

0


/V


50


+

V =


A

-1

-2 V

-3

-4

-5

-6

LARGE-SIGNAL GAIN vs. FREQUENCY

MAX4174 TOC05

MAX4174 TOC06

4

3

NORMALIZED GAIN (dB)

2 AV = +51V/V

1

0

-1

AV = +100V/V

-2

-3

-4

-5

-6

1k 10k 100k 1M FREQUENCY (Hz)

10M

1k 10k 100k 1M FREQUENCY (Hz)

10M

1k 10k 100k 1M FREQUENCY (Hz)

10M

SMALL-SIGNAL GAIN vs. FREQUENCY

4

3

NORMALIZED GAIN (dB)

2 AV = +1.25V/V

1

0

-1

-2

-3

-4 AV = +2.25V/V

-5

-6

SMALL-SIGNAL GAIN vs. FREQUENCY

MAX4174 TOC07

4

3

NORMALIZED GAIN (dB)

2 AV = +2.5V/V

1

0

/V

-1

-2 AV = +4V

-3

-4

-5

-6

SMALL-SIGNAL GAIN vs. FREQUENCY

MAX4174 TOC08

MAX4174 TOC09

4

3

NORMALIZED GAIN (dB)

2 AV = +5V/V

1

0

-1

-2 AV = +9V/V

-3

-4

-5

-6

1k 10k 100k 1M FREQUENCY (Hz)

10M

1k 10k 100k 1M FREQUENCY (Hz)

10M

1k 10k 100k 1M FREQUENCY (Hz)

10M

SMALL-SIGNAL GAIN vs. FREQUENCY

4

3

NORMALIZED GAIN (dB)

2 AV = +10V/V

1

0

-1

-2

-3

-4 AV = +21V/V

-5

1k

10k 100k 1M

10M

1k

10k 100k 1M

10M

1k

10k 100k 1M

10M


FREQUENCY (Hz)



FREQUENCY (Hz)



FREQUENCY (Hz)


-6

SMALL-SIGNAL GAIN vs. FREQUENCY

MAX4174 TOC10

4

3

NORMALIZED GAIN (dB)

2 AV = +25V/V

1

0

-1

-2

-3

-4 AV = +50V/V

-5

-6

SMALL-SIGNAL GAIN vs. FREQUENCY

MAX4174 TOC11

MAX4174 TOC12

4

3

NORMALIZED GAIN (dB)

2 AV = +51V/V

1

0

-1

-2

-3 AV = +100V/V

-4

-5

-6


MAX4174/5, MAX4274/5, MAX4281/2/4

Typical Operating Characteristics (continued)

(VCC = +5V, RL = 100k to VCC / 2, small-signal VOUT = 100mVp-p, large-signal VOUT = 1Vp-p, TA = +25°C, unless otherwise noted.)

MAX4174/MAX4175


0


-20

TOTAL HARMONIC DISTORTION vs. FREQUENCY

VOUT = 1Vp-p


0


-20

TOTAL HARMONIC DISTORTION vs. FREQUENCY

-p

MAX4174 TOC14

VOUT = 1Vp


THD (dB)

-40


-60


-80


AV = +10V/V

AV = +1.25V/V

-40


MAX4174 TOC13

THD (dB)

-60


-80


AV = +51V/V


-100


-120


-60


-70


THD (dB)

-80


-90


-100


-110


AV = +3V/V

1k 10k 100k 1M FREQUENCY (Hz)

TOTAL HARMONIC DISTORTION vs. OUTPUT VOLTAGE SWING

MAX4174 TOC15

f = 10kHz


AV = +10V/V


AV = +1.25V/V AV = +3V/V

-100


-120


-60


-70


THD (dB)

-80


-90


-100


-110

AV = +25V/V


1k 10k 100k 1M FREQUENCY (Hz)

MAX4174 TOC16

TOTAL HARMONIC DISTORTION vs. OUTPUT VOLTAGE SWING


-120

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)

-120

f = 10kHz












AV = +51V/V





















AV = +25V/V






















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)


VOLTAGE NOISE DENSITY (nV/Hz)

1000


100


10


VOLTAGE NOISE DENSITY vs. FREQUENCY (AV = +1.25, +3, +10)






















































































AV = +10V/V



















AV

= +3V/V















































































AV = +1.25V/V


































MAX4174/5 toc 17

1 10 100 1k 10k 100k


1000


VOLTAGE NOISE DENSITY (nV/Hz)

100


10


VOLTAGE NOISE DENSITY vs. FREQUENCY (AV = +25, +51)


MAX4174/5 toc 18

AV = +25V/V


AV = +51V/V


INCLUDES RESISTOR NOISE


1 10 100 1k 10k 100k


CURRENT NOISE DENSITY vs.

FREQUENCY

CURRENT NOISE DENSITY (fA/Hz)

MAX4174/5 toc19

10


1

1 10 100 1k 10k 100k


MAX4174/5, MAX4274/5, MAX4281/2/4

Typical Operating Characteristics (continued)

(VCC = +5V, RL = 100k to VCC / 2, small-signal VOUT = 100mVp-p, large-signal VOUT = 1Vp-p, TA = +25°C, unless otherwise noted.)

MAX4174/MAX4175

MAX4174/5 toc 20

LARGE-SIGNAL PULSE RESPONSE

SMALL-SIGNAL PULSE RESPONSE



INPUT VOLTAGE


AV = +1.25V/V

OUTPUT

500mV/div


AV = +3V/V OUTPUT

50mV/div


AV = +5V/V OUTPUT

500mV/div


AV = +10V/V OUTPUT

500mV/div


AV = +25V/V OUTPUT

500mV/div


AV = +51V/V OUTPUT

500mV/div


INPUT VOLTAGE


MAX4174/5 toc 21

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 OUTPUT

50mV/div



CL = 0


2s/div


CL = 0

2s/div


MAX4174/5, MAX4274/5, MAX4281/2/4

PSR (dB)

Typical Operating Characteristics (continued)

(VCC = +5V, RL = 100k to VCC / 2, small-signal VOUT = 100mVp-p, large-signal VOUT = 1Vp-p, TA = +25°C, unless otherwise noted.)

MAX4174/MAX4175/MAX4281/MAX4282/MAX4284


-70


-75


-80


-85


-90


-95

POWER-SUPPLY REJECTION vs. FREQUENCY


MAX4174 TOC22

100


OUTPUT IMPEDANCE ()

10


1


0.1


0.01

OUTPUT IMPEDANCE vs. FREQUENCY


MAX4174 TOC23

5.0

4.9

4.8

VSWING (Vp-p)

4.7

4.6

4.5

4.4

4.3

4.2

4.1

MAX4174 TOC24

4.0

OUTPUT VOLTAGE SWING vs. RLOAD

100

1k 10k 100k 1M FREQUENCY (Hz)

100

1k 10k 100k 1M FREQUENCY (Hz)

1 10 100

RLOAD (k)


200


INPUT OFFSET VOLTAGE (V)

150


100


50


0


-50


-100


-150


MAX4174/5 toc 26

-200

INPUT OFFSET VOLTAGE vs.

MAX4174/5 toc 25

TEMPERATURE


VCC = 2.5V VCC = 5.5V


1000


INPUT BIAS CURRENT (pA)

800


600


400


200


0


-200

INPUT BIAS CURRENT vs. TEMPERATURE

























VCC = 5.5V























VCC = 2.5V










-50

-35 -20

-5 10

25 40 55 70 85

-45

-30

-15

0 15 30 45 60 75 90


380


360

TEMPERATURE (°C)


MAX4174/5 toc 27

SUPPLY CURRENT vs. TEMPERATURE


VCC = 5.5V

VCC = 5V

VCC = 4V


100

80

60


VOH AND VOL vs. TEMPERATURE (VCC = 2.5V)


VOH, RL = 1k

VOH, RL = 100k


200

MAX4174/5 toc 28

180

160

140

TEMPERATURE (°C)


MAX4174/5 toc 29

VOH AND VOL vs. TEMPERATURE (VCC = 5.5V)


VOH, RL = 1k

SUPPLY CURRENT (A)

VOLTAGE (mV)

340

40 V

, R = 10k

120


320

OH L

20

0

100

VOLTAGE (mV)

80

60

VOH, RL = 100k VOH, RL = 10k V


, R = 100k

300

-20


VOL, RL = 100k

40

20

V , R = 10k

OL L

280


260


240


VCC = 3V


VCC = 2.5V

-40

-60

-80

-100


VOL, RL = 1k

OL L

0

-20

-40

-60

-80

-100


VOL, RL = 1k


VOL, RL = 100k

-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)


MAX4174/5, MAX4274/5, MAX4281/2/4

Typical Operating Characteristics

(VCC = +5V, RL = 100k to VCC / 2, small-signal VOUT = 100mVp-p, large-signal VOUT = 1Vp-p, TA = +25°C, unless otherwise noted.)

MAX4281/MAX4282/MAX4284


160

140

120

100

OPEN-LOOP GAIN (dB)

80

60

40

20

0

-20

-40

OPEN-LOOP GAIN AND PHASE vs. FREQUENCY


MAX4174/5 toc30



















































































































































































































4

3

2

PHASE (degrees)

1

GAIN (dB)

0

0 -1

-45 -2

-90

-135 -3

-180 -4

-225

-270 -5

-315 -6

SMALL-SIGNAL GAIN vs. FREQUENCY

LARGE-SIGNAL GAIN vs. FREQUENCY

MAX4174/5 toc31

MAX4174/5 toc32

4

3

2

1

GAIN (dB)

0

-1

-2

-3

-4

-5

-6

1 10

100 1k

10k

100k 1M

10M

1k 10k 100k 1M 10M

1k 10k 100k 1M 10M


0

-10

-20

-30

CMR (dB)

-40

-50

-60

-70

-80

-90

-100

FREQUENCY (Hz)


MAX4174/5 toc33

MAX4174/5 toc34

COMMON-MODE REJECTION vs. FREQUENCY


VOLTAGE NOISE DENSITY (nV/Hz)

1000


100


10

FREQUENCY (Hz)


VOLTAGE NOISE DENSITY vs. FREQUENCY

FREQUENCY (Hz)


CURRENT NOISE DENSITY vs. FREQUENCY

CURRENT NOISE DENSITY (fA/Hz)

MAX4174/5 toc35

10


1

100

1k 10k 100k FREQUENCY (Hz)

1M 10M

1 10 100 1k FREQUENCY (Hz)

10k 100k

1 10 100 1k FREQUENCY (Hz)

10k 100k


0

-10

-20

-30

-40

THD (dB)

-50

-60

-70

-80

-90

-100

-110

-120

TOTAL HARMONIC DISTORTION vs. FREQUENCY


AV = 1

VOUT = 1Vp-

p


-50

-55

-60

CROSSTALK (dB)

-65

-70

-75

-80

-85

-90

-95

MAX4282 CROSSTALK vs. FREQUENCY

MAX4284 CROSSTALK vs. FREQUENCY

MAX4174/5 toc37

MAX4174/5 toc38

-50 THREE AMPLIFIERS DRIVEN, ONE OUTPUT MEASURED

CROSSTALK (dB)

-55


-60


-65


-70


-75

MAX4174/5 toc36

1k 10k 100k 1M FREQUENCY (Hz)

1k 10k 100k FREQUENCY (Hz)

1M 10M

1k 10k 100k FREQUENCY (Hz)

1M 10M


MAX4174/5, MAX4274/5, MAX4281/2/4

Pin Description


PIN




NAME


FUNCTION

MAX4281

MAX4174/ MAX4175

MAX4282

MAX4274/ MAX4275

MAX42

84

5 SOT23

8 SO

5 SOT23

8 SO/µMAX

8 SO/µMAX

14 SO/TSSOP

16 QSOP

NAME

FUNCTION


1


6


1


1, 7


1, 7


1, 7,

8, 14


1, 7,

10, 16

OUT, OUTA, OUTB, OUTC, OUTD


Amplifier Output

2

4

2

4

4

11

13

VEE

Negative Supply or Ground


3


3


3


3, 5


3, 5


3, 5,

10, 12


3, 5,

12, 14


IN+, INA+, INB+, INC+, IND+

Noninverting Amplifier Input. Internally biased to VCC / 2 for MAX4175/MAX4275


4


2


4


2, 6


2, 6


2, 6,

9, 13


2, 6,

11, 15

IN-, INA-,

INB-, INC-, IND-

Inverting Amplifier Input. Connects to RG for MAX4174/ 4175/4274/4275.

5

7

5

8

8

4

4

VCC

Positive Supply


1, 5,

8






8, 9


N.C.

No Connection. Not internally connected.


IN-

VEE

RF

G

EE

R

V

IN-

RF

RG

IN+

OUT

OUT

MAX4175

MAX4174

IN+

MAX4281

Functional Diagrams



VCC

VCC

VCC

VCC


IN+

RB 150k


IN-

RB

150k

OUT



VEE


VEE


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. Three versions are available in this amplifier family: single/dual/quad open-loop, unity-gain-stable devices (MAX4281/MAX4282/MAX4284); single/dual fixed-gain devices (MAX4174/MAX4274); and single/ dual devices with fixed gain plus internal V CC / 2 bias at the noninverting input (MAX4175/MAX4275). All amplifiers feature rail-to-rail outputs and drive a 1k load while maintaining excellent DC accuracy.

Open-Loop Op Amps The single/dual/quad MAX4281/MAX4282/MAX4284 are high-performance, open-loop op amps with rail-to- rail outputs. These devices are compensated for unity- gain stability, and feature a gain bandwidth (GBW) of 2MHz. The op amps in these ICs feature an input com- mon-mode range that extends from 150mV below the negative rail to within 1.2V of the positive rail. These high performance op amps serve as the core for this family of GainAmp fixed-gain amplifiers. Although the

-3dB bandwidth 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.

Internal Gain-Setting Resistors Maxim’s proprietary laser trimming techniques produce the necessary R F/RG values (Figure 1), so many gain offerings are easily available. These GainAmp fixed-gain amplifiers feature a negative-feedback resistor network that is laser trimmed to provide a gain-setting feedback ratio (R F/RG) with 0.1% typical accuracy. The standard op amp pinouts allow the GainAmp fixed-gain amplifiers to drop in directly to existing board designs, easily replacing op-amp-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 decompen- sated strategic ally over the gain-set options to maxi- mize bandwidth. Open-loop decompensation increases GBW product, ensuring that usable bandwidth is main- tained with increasing closed-loop gains. A GainAmp with a fixed gain of A V = 100V/V has a -3dB bandwidth of 230kHz. By comparison, a unity-gain-stable op amp configured for A V = 100V/V would yield a -3dB band- width of only 20kHz (Figure 2). Decompensation is per- formed at five intermediate gain sets, as shown in the Gain Selection Guide. Low gain decompensation great-

ly increases usable bandwidth, while decompensation above gains of +25V/V offers diminished returns.

MAX4174/5, MAX4274/5, MAX4281/2/4

VCC / 2 Internal Bias The MAX4175/MAX4275 GainAmp fixed-gain amplifiers with the V CC / 2 bias option are identical to standard GainAmp fixed-gain amplifiers, with the added feature of VCC / 2 internal bias at the noninverting inputs. Two 150k resistors form a voltage-divider for self-biasing the noninverting input, eliminating external bias resis- tors for AC-coupled applications, and allowing maxi- mum signal swing at the op amp’s rail-to-rail output for single-supply systems (see Typical Operating Circuit ). For DC-coupled applications, use the MAX4174/ MAX4274.

High-Voltage (±17V) Input Fault Protection

The MAX4174/MAX4175/MAX4274/MAX4275 include

RG

RG

±17V input fault protection. For normal operation, see the input voltage range specification in the Electrical Characteristics. Overdriven inputs up to ±17V will not



VCC

AV = -RF


IN-

RG

RF

AV = 1 + RF



VEE


OUT


IN+


20kHz

230kHz

GAIN (dB)

Figure 1. Internal Gain-Setting Resistors


60


50


40

-3dB

30

MAX4281, AV = 100 2MHz GBW

MAX4174, AV = 100 23MHz GBW


20


10


0

10 100 1k 10k 100k 1M 10M

FREQUENCY (Hz)

Figure 2. Gain-Bandwidth Comparison


MAX4174/5, MAX4274/5, MAX4281/2/4

cause output phase reversal. A back-to-back SCR structure at the input pins allows either input to safely swing ±17V relative to V EE (Figure 3). Additionally, the internal op-amp inputs are diode clamped to either supply rail for the protection of sensitive input stage cir- cuitry. Current through the clamp diodes is limited by a 5k resistor at the noninverting input, and by R G at the inverting input. An IN+ or IN- fault voltage as high as

±17V will cause less than 3.5mA of current to flow through the input pin, protecting both the GainAmp and the signal source from damage.

Applications Information

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 that 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 MAX4174/MAX4175/MAX4274/MAX4275 combine

both an op amp and gain-setting feedback resistors on the same chip. Because the inverting input pin is actu- ally tied to the R G input series resistor, the inverting input voltage range is different from the noninverting input voltage range. Just as with a discrete design, care must be taken not to saturate the inputs/output of the core op amp, to avoid signal distortions or clipping.

The inverting inputs (IN_-) of the MAX4174/MAX4175/ MAX4274/MAX4275 must be within the supply rails or signal distortion may result. The GainAmp’s inverting input structure includes diodes to both supplies, such that driving the inverting input beyond the rails may cause signal distortions (Figure 1). For applications that require sensing voltages beyond the rails, use the MAX4281/MAX4282/MAX4284 open-loop op amps (Figure 4).


RF


IN-

RG


17V SCR


VEE

VCC

VCC

MAX4174 MAX4175 MAX4274 MAX4275

OUT

IN+

5k


17V SCR


VEE

VEE

VEE

NOTE: INPUT STAGE PROTECTION INCLUDES

TWO 17V SCRs AND TWO DIODES AT THE INPUT STAGE.



BIAS RESISTORS (MAX4175/MAX4275 ONLY)


Figure 3. Input Protection


MAX4281

VCC

VCC

MAX4175


RB


VCC

0.1F

RB

V = - V

RG

)


VIN

RG

RF

VOUT = -RF (VIN)

VIN

RG

RF


RG

VOUT = VIN (1+ RF )

VIN

RG

VOUT = - VIN ( RF )

2

F

R

IN (

OUT

VCC

RG

MAX4174/5, MAX4274/5, MAX4281/2/4

Figure 4. Single-Supply, DC-Coupled Inverting Amplifier with Negative Input Voltage

Figure 6. Single-Supply, AC-Coupled Inverting Amplifier


MAX4174

VCC

VCC

MAX4174


VIN

VEE

VEE


RF


RG

RF

RG

Figure 5. Dual-Supply, DC-Coupled Inverting Amplifier


GainAmp Signal Coupling and Configurations

Common op-amp configurations include both nonin- verting and inverting amplifiers. Figures 5–8 show vari- ous single and dual-supply circuit configurations. Single-supply systems benefit from a midsupply bias on the noninverting input (provided internally on MAX4175/MAX4275), as this produces a quiescent DC level at the center of the rail-to-rail output stage signal swing. For dual-supply systems, ground-referenced signals may be DC-coupled into the inverting or non- inverting inputs.

Figure 7. Dual-Supply, AC-Coupled Noninverting Amplifier


IN_+ Filter on MAX4175/MAX4275 Internal resistor biasing of the VCC / 2 bias options cou- ples power-supply noise directly to the op amp’s nonin- verting input. To minimize high-frequency power-supply noise coupling, add a 1µF to 0.1µF capacitor from IN+ to ground to create a lowpass filter (Figure 6). The low- pass filter resulting from the internal bias resistors and added capacitor can help eliminate higher frequency power-supply noise coupling through the noninverting input.


MAX4174/5, MAX4274/5, MAX4281/2/4

Supply Bypassing and Board Layout All devices in the 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 supplies, bypass each supply to ground. Bypass with capacitors as close to the device as possible, to min- imize lead inductance and noise. A printed circuit board with a low-inductance ground plane is recommended.

RG

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 470pF. Stability with higher capacitive loads can be improved by adding an isolation resistor in series with the op-amp output, as shown in Figure 9. This resistor improves the circuit’s phase mar- gin by isolating the load capacitor from the amplifier’s output. In Figure 10, a 1000pF capacitor is driven with a 100 isolation resistor exhibiting some overshoot but no oscillation. Figures 11 and 12 show the typical small-sig- nal pulse responses of GainAmp fixed-gain amplifiers with 250pF and 470pF capacitive loads and no isolation resistor.



VCC

MAX4174

INPUT

VIN

VOUT = VIN (1+ RF )

AV = +5V/V

50mV/div

OUTPUT


RG


OUTPUT

AV = +5V/V

500mV/div

VEE


RF

Figure 8. Dual-Supply, DC-Coupled Noninverting Amplifier

Figure 10. Small-Signal/Large-Signal Transient Response with Excessive Capacitive Load with Isolation Resistor



MAX4174


RG

RF


VCC


RISO

OUTPUT


INPUT

CL

RL

VEE



Figure 9. Dual-Supply, Capacitive-Load Driving Circuit



INPUT


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 OUTPUT

50mV/div


2s/div


INPUT


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 OUTPUT

50mV/div


2s/div

MAX4174/5, MAX4274/5, MAX4281/2/4

Figure 11. MAX4174/MAX4175 Small-Signal Pulse Response (CL = 250pF, RL = 100k)

Figure 12. MAX4174/MAX4175 Small-Signal Pulse Response (CL = 470pF, RL = 100k)


MAX4174/5, MAX4274/5, MAX4281/2/4

Gain Selection Guide


GAIN CODE

RF/RG INVERTING GAIN

1+ (RF/RG) NONINVERTING GAIN

-3dB BW

(kHz)

TOP MARK

MAX4174

MAX4175

AB*

0.25

1.25

1700

ACDS

ACET

AC

0.5

1.5

1280

ACDT

ACEU

AD*

1

2

590

ACDU

ACEV

AE

1.25

2.25

450

ACDV

ACEW

AF

1.5

2.5

1180

ACDW

ACEX

AG*

2

3

970

ACDX

ACEY

AH

2.5

3.5

820

ACDY

ACEZ

AJ

3

4

690

ACDZ

ACFA

AK*

4

5

970

ACEA

ACFB

AL

5

6

790

ACEB

ACFC

AM

6

7

640

ACEC

ACFD

AN

8

9

480

ACED

ACFE

AO*

9

10

640

ACEE

ACFF

BA*

10

11

560

ACEF

ACFG

BB

12.5

13.5

460

ACEG

ACFH

BC

15

16

390

ACEH

ACFI

BD

20

21

300

ACEI

ACFJ

BE*

24

25

590

ACEJ

ACFK

BF

25

26

580

ACEK

ACFL

BG

30

31

510

ACEL

ACFM

BH

40

41

390

ACEM

ACFN

BJ*

49

50

310

ACEN

ACFO

BK*

50

51

330

ACEO

ACFP

BL

60

61

310

ACEP

ACFQ

BM

80

81

260

ACEQ

ACFR

BN*

99

100

230

ACER

ACFS

CA*

100

101

230

ACES

ACFT

Note: Gains in the noninverting configuration are 1+ (RF/RG) and range from +1.25V/V to +101V/V. For a +1V/V gain, use the MAX4281/MAX4282/MAX4284.

* Preferred Gains. These gain versions are available as samples and in small quantities.

The -3dB bandwidth is the same for inverting and noninverting configurations.


MAX4174/5, MAX4274/5, MAX4281/2/4

Pin Configurations (continued)


TOP VIEW



OUT 1

MAX4175


5 VCC

MAX4281


5

1

OUT VCC


VEE 2


IN+ 3

+ - RF


R RG

R

VCC 4

VEE

IN+

+ -

4

3

2

IN-

SOT23-5 SOT23-5

N.C.

IN-

MAX4281


1



2


N.C.


7

8

VCC


OUTA 1


INA- 2


MAX4282


8 VCC


7 OUTB


OUTA 1


INA- 2


MAX4274


8

RF


7

RG RF


VCC


OUTB


3

IN+


6

OUT


INA+ 3

+ -

6 INB-


INA+ 3

+ -

6 INB-

RG


VEE

N.C.


5

4

SO

VEE 4


MAX/SO

5 INB+

VEE 4


MAX/SO

5 INB+



OUTA 1


INA- 2


MAX4275


RF RG

VCC RF

+ -


8 VCC


7 OUTB


OUTA 1


INA- 2


INA+ 3


MAX4284


+ -


14 OUTD


13 IND-


12 IND+


OUTA 1


INA- 2


INA+ 3


MAX4284


+ -


16 OUTD


15 IND-


14 IND+

R RG

INA+ 3

R

6

VCC

INB-

VCC 4

11 VEE

VCC 4

13 VEE


+ -

VEE 4

R R

5 INB+


INB+ 5


10 INC+


INB+ 5


12 INC+


MAX/SO


INB- 6


OUTB 7


SO/TSSOP


9 INC-


8 OUTC


INB- 6


OUTB 7


N.C. 8


11 INC-


+ -

10 OUTC


9 N.C.


QSOP


MAX4174/5, MAX4274/5, MAX4281/2/4

Ordering Information (continued) Chip Information

PART*

TEMP. RANGE

PIN- PACKAGE

TOP MARK

MAX4274_EUA

-40°C to +85°C

8 µMAX

MAX4274_ESA

-40°C to +85°C

8 SO

MAX4275_EUA

-40°C to +85°C

8 µMAX

MAX4275_ESA

-40°C to +85°C

8 SO

MAX4281EUK-T

-40°C to +85°C

5 SOT23-5

ACDR

MAX4281ESA

-40°C to +85°C

8 SO

MAX4282EUA

-40°C to +85°C

8 µMAX

MAX4282ESA

-40°C to +85°C

8 SO

MAX4284EUD

-40°C to +85°C

14 TSSOP

MAX4284ESD

-40°C to +85°C

14 SO

MAX4284EEE

-40°C to +85°C

16 QSOP

TRANSISTOR COUNTS:

MAX4174: 178

MAX4175: 178

MAX4274: 332

MAX4275: 332

MAX4281: 178

MAX4282: 332

MAX4284: 328 SUBSTRATE CONNECTED TO VEE


Note: Refer to Gain Selection Guide for SOT top marks.

*Insert the desired gain code (from the Gain Selection Guide) in the blank to complete the part number. Refer to Gain Selection Guide for a list of preferred gains.


Selector Guide



PART*

INVERTING GAINS AVAILABLE (V/V) (INVERTING, RF/RG)

NONINVERTING GAIN

(V/V)

INTERNAL RESISTORS

INTERNAL VCC/2 BIAS

NO. OF AMPS PER PACKAGE


PIN-PACKAGE

MAX4174_

-0.25 to -100

+1.25 to +101

Yes

No

1

5-pin SOT23

MAX4175_

-0.25 to -100

+1.25 to +101

Yes

Yes

1

5-pin SOT23

MAX4274_

-0.25 to -100

+1.25 to +101

Yes

No

2

8-pin µMAX/SO

MAX4275_

-0.25 to -100

+1.25 to +101

Yes

Yes

2

8-pin µMAX/SO

MAX4281_

Open Loop, Unity-Gain Stable

No

No

1

5-pin SOT23,

8-pin SO

MAX4282_

Open Loop, Unity-Gain Stable

No

No

2

8-pin µMAX/SO

MAX4284_

Open Loop, Unity-Gain Stable

No

No

4

14-pin SO/TSSOP, 16-pin QSOP

* Insert the desired gain code (from the Gain Selection Guide) in the blank to complete the part number.


MAX4174/5, MAX4274/5, MAX4281/2/4

SOT5L.EPS

Package Information












MAX4174/5, MAX4274/5, MAX4281/2/4

8LUMAXD.EPS

Package Information












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