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MAX4475–MAX4478/ MAX4488/MAX4489


SOT23, Low-Noise, Low-Distortion, Wide-Band, Rail-to-Rail Op Amps


General Description

The MAX4475–MAX4478/MAX4488/MAX4489 wide-

band, low-noise, low-distortion operational amplifiers offer rail-to-rail outputs and single-supply operation down to 2.7V. They draw 2.2mA of quiescent supply current per amplifier while featuring ultra-low distortion (0.0002% THD+N), as well as low input voltage-noise density (4.5nV/√Hz) and low input current-noise density (0.5fA/√Hz). These features make the devices an ideal choice for applications that require low distortion and/or low noise.

For power conservation, the MAX4475/MAX4488 offer a low-power shutdown mode that reduces supply cur- rent to 0.01µA and places the amplifiers’ outputs into a high-impedance state. These amplifiers have outputs which swing rail-to-rail and their input common-mode voltage range includes ground. The MAX4475–MAX4478 are unity-gain stable with a gain-bandwidth product of 10MHz. The MAX4488/4489 are internally compen- sated for gains of +5V/V or greater with a gain-band- width product of 42MHz. The single MAX4475/MAX4476/ MAX4488 are available in space-saving, 6-pin SOT23 and TDFN packages.

Applications


Ordering Information at end of data sheet.


25


20


15


10


5


0

VIN EQUIVALENT INPUT NOISE VOLTAGE (nVHz)

MAX4475 toc20

Typical Operating Characteristic


INPUT VOLTAGE-NOISE DENSITY vs. FREQUENCY



10 100

1k

FREQUENCY (Hz)

10k 100k


Pin Configurations and Typical Operating Circuit appear at end of data sheet.


19-2137; Rev 11; 4/19


Absolute Maximum Ratings

Power-Supply Voltage (VDD to VSS)....................-0.3V to +6.0V Analog Input Voltage (IN_+, IN_-) . (VSS - 0.3V) to (VDD + 0.3V) SHDN Input Voltage ..................................(VSS - 0.3V) to +6.0V

Output Short-Circuit Duration to Either Supply ......... Continuous

Continuous Input Current (IN+, IN-) .................................±10mA

Continuous Power Dissipation (TA = +70°C)

6-Pin SOT23 (derate 5.4mW/°C above +70°C) .......431.3mW

6-Pin TDFN (derate 18.2mW/°C above 70°C) ..........1454mW

8-Pin µMAX (derate 4.5mW/°C above +70°C) ............362mW


8-Pin SO (derate 5.88mW/°C above +70°C)...............471mW

14-Pin SO (derate 8.33mW/°C above +70°C).............667mW 14-Pin TSSOP (derate 9.1mW/°C above +70°C)........727mW Operating Temperature Range......................... -40°C to +125°C Junction Temperature ...................................................... +150°C

Storage Temperature Range ............................ -65°C to +150°C

Lead Temperature (soldering, 10s) ................................. +300°C

Soldering Temperature (reflow) ....................................... +260°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.


Package Information

SOT23-6

PACKAGE CODE

U6F+6

Outline Number

21-0058

Land Pattern Number

90-0175

Thermal Resistance, Single-Layer Board

Junction to Ambient (θJA)

185.5°C/W

Junction to Case (θJC)

75°C/W

Thermal Resistance, Multi-Layer Board

Junction to Ambient (θJA)

134.4°C/W

Junction to Case (θJC)

39°C/W

µMAX-8

PACKAGE CODE

U8+4

Outline Number

21-0036

Land Pattern Number

90-0092

Thermal Resistance, Multi-Layer Board

Junction to Ambient (θJA)

206°C/W

Junction to Case (θJC)

42

µMAX-8

PACKAGE CODE

U8+1

Outline Number

21-0036

Land Pattern Number

90-0092

Thermal Resistance, Single-Layer Board

Junction to Ambient (θJA)

221°C/W

Junction to Case (θJC)

42°C/W

Thermal Resistance, Multi-Layer Board

Junction to Ambient (θJA)

206°C/W

Junction to Case (θJC)

42°C/W


Package Information (continued)

TSSOP-14

PACKAGE CODE

U14+2

Outline Number

21-0066

Land Pattern Number

90-0113

Thermal Resistance, Single-Layer Board

Junction to Ambient (θJA)

110°C/W

Junction to Case (θJC)

30°C/W

Thermal Resistance, Multi-Layer Board

Junction to Ambient (θJA)

100.4°C/W

Junction to Case (θJC)

30°C/W

SO-8

PACKAGE CODE

S8+4

Outline Number

21-0041

Land Pattern Number

90-0096

Thermal Resistance, Single-Layer Board

Junction to Ambient (θJA)

170°C/W

Junction to Case (θJC)

40

Thermal Resistance, Multi-Layer Board

Junction to Ambient (θJA)

132°C/W

Junction to Case (θJC)

38

SO-14

PACKAGE CODE

S14+4

Outline Number

21-0041

Land Pattern Number

90-0112

Thermal Resistance, Single-Layer Board

Junction to Ambient (θJA)

120°C/W

Junction to Case (θJC)

37°C/W

Thermal Resistance, Multi-Layer Board

Junction to Ambient (θJA)

84°C/W

Junction to Case (θJC)

34°C/W


Package Information (continued)

TDFN-6

PACKAGE CODE

T633+2

Outline Number

21-0137

Land Pattern Number

90-0058

Thermal Resistance, Single-Layer Board

Junction to Ambient (θJA)

55°C/W

Junction to Case (θJC)

9°C/W

Thermal Resistance, Multi-Layer Board

Junction to Ambient (θJA)

42°C/W

Junction to Case (θJC)

9°C/W

For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status.

Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.


DC Electrical Characteristics

(VDD = +5V, VSS = 0V, VCM = 0V, VOUT = VDD/2, RL tied to VDD/2, SHDN = VDD, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.) (Notes 1, 2)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

Supply Voltage Range

VDD

(Note 3)

2.7


5.5

V


Quiescent Supply Current Per Amplifier


ID


Normal mode

VDD = 3V

2.2


mA

VDD = 5V


2.5

4.4

Shutdown mode (SHDN = VSS) (Note 2)


0.01

1.0

µA


Input Offset Voltage

VOS

TA = +25°C


±70

±350


µV

TA = -40°C to +125°C

±750

Input Offset Voltage Tempco

TCVOS



±0.3

±6

µV/°C

Input Bias Current

IB

(Note 4)


±1

±150

pA

Input Offset Current

IOS

(Note 4)


±1

±150

pA

Differential Input Resistance

RIN


1000

GΩ

Input Common-Mode Voltage Range

VCM

Guaranteed by CMRR Test

TA = +25°C

-0.2


VDD - 1.6


V

TA = -40°C to +125°C

-0.1


VDD - 1.7


Common-Mode Rejection Ratio


CMRR

(VSS - 0.2V) ≤ VCM ≤ (VDD – 1.6V)


TA = +25°C


90


115



dB

(VSS - 0.1V) ≤ VCM ≤ (VDD – 1.7V)


TA = -40°C to +125°C


90

Power-Supply Rejection Ratio

PSRR

VDD = 2.7 to 5.5V

90

120


dB


Large-Signal Voltage Gain


AVOL

RL = 10k to VDD/2;

VOUT = 100mV to (VDD - 125mV)

90

120



dB

RL = 1k to VDD/2;

VOUT = 200mV to (VDD - 250mV)

85

110


RL = 500 to VDD/2;

VOUT = 350mV to (VDD - 500mV)

85

110



Output Voltage Swing


VOUT

|VIN+ - VIN-| ≥ 10mV,

RL = 10k to VDD/2

VDD - VOH


10

45


mV

VOL - VSS


10

40

|VIN+ - VIN-| ≥ 10mV,

RL = 1k to VDD/2

VDD - VOH


80

200

VOL - VSS


50

150

|VIN+ - VIN-| ≥ 10mV,

RL = 500 to VDD/2

VDD - VOH


100

300

VOL - VSS


80

250

Output Short-Circuit Current

ISC


48

mA

Output Leakage Current

ILEAK

Shutdown mode (SHDN = VSS), VOUT = VSS to VDD


±0.001

±1.0

µA

SHDN Logic-Low

VIL


0.3 x VDD

V

SHDN Logic-High

VIH


0.7 x VDD

V

SHDN Input Current


SHDN = VSS to VDD

0.01 1

µA

Input Capacitance

CIN


10

pF


AC Electrical Characteristics

(VDD = +5V, VSS = 0V, VCM = 0V, VOUT = VDD/2, RL tied to VDD/2, SHDN = VDD, TA = +25°C.)


PARAMETER

SYMBOL

CONDITIONS

MIN TYP MAX

UNITS

Gain-Bandwidth Product

GBWP

MAX4475–MAX4478

AV = +1V/V

10

MHz

MAX4488/MAX4489

AV = +5V/V

42

Slew Rate

SR

MAX4475–MAX4478

AV = +1V/V

3

V/µs

MAX4488/MAX4489

AV = +5V/V

10

Full-Power Bandwidth (Note 5)


MAX4475–MAX4478

AV = +1V/V

0.4

MHz

MAX4488/MAX4489

AV = +5V/V

1.25

Peak-to-Peak Input Noise Voltage

en(P-P)

f = 0.1Hz to 10Hz

260

nVP-P


Input Voltage-Noise Density


en

f = 10Hz

21


nV/√Hz

f = 1kHz

4.5

f = 30kHz

3.5

Input Current-Noise Density

in

f = 1kHz

0.5

fA/√Hz


Total Harmonic Distortion Plus Noise (Note 6)


THD + N

VOUT = 2VP-P,

AV = +1V/V (MAX4475–MAX4478),

RL = 10k to GND

f = 1kHz

0.0002


%

f = 20kHz

0.0007

VOUT = 2VP-P,

AV = +1V/V (MAX4475–MAX4478),

RL = 1k to GND

f = 1kHz

0.0002

f = 20kHz

0.001

VOUT = 2VP-P,

AV = +5V/V (MAX4488/ MAX4489),

RL = 10k to GND

f = 1kHz

0.0004

f = 20kHz

0.0006


Total Harmonic Distortion Plus Noise (Note 6)


THD + N

VOUT = 2VP-P,

AV = +5V/V (MAX4488/MAX4489),

RL = 1k to GND

f = 1kHz

0.0005


%

f = 20kHz

0.008

Capacitive-Load Stability


No sustained oscillations

200

pF

Gain Margin

GM


12

dB


Phase Margin

M

MAX4475–MAX4478, AV = +1V/V

70


degrees

MAX4488/MAX4489, AV = +5V/V

80

Settling Time


To 0.01%, VOUT = 2V step

2

µs

Delay Time to Shutdown

tSH


1.5

µs

Enable Delay Time from Shutdown

tEN

VOUT = 2.5V, VOUT settles to 0.1%

10

µs

Power-Up Delay Time


VDD = 0 to 5V step, VOUT stable to 0.1%

13

µs

Note 1: All devices are 100% tested at TA = +25°C. Limits over temperature are guaranteed by design.

Note 2: SHDN is available on the MAX4475/MAX4488 only.

Note 3: Guaranteed by the PSRR test.

Note 4: Guaranteed by design.

Note 5: Full-power bandwidth for unity-gain stable devices (MAX4475–MAX4478) is measured in a closed-loop gain of +2V/V to accommodate the input voltage range, VOUT = 4VP-P.

Note 6: Lowpass-filter bandwidth is 22kHz for f = 1kHz and 80kHz for f = 20kHz. Noise floor of test equipment = 10nV/√Hz.


Typical Operating Characteristics

(VDD = +5V, VSS = 0V, VCM = 0V, VOUT = VDD/2, RL tied to VDD/2, input noise floor of test equipment =10nV/√Hz for all distortion measurements, TA = +25°C, unless otherwise noted.)



INPUT OFFSET VOLTAGE DISTRIBUTION

MAX4475-8 toc1
























































































































18

16

PERCENTAGE OF UNITS (%)

14

12

10

8

6

4

2

0


250

INPUT OFFSET VOLTAGE (V)

200

150

100

50

0

-50

-100

-150

-200

-250


VCOM = 0V





































































OFFSET VOLTAGE vs. TEMPERATURE

INPUT OFFSET VOLTAGE

vs. INPUT COMMON-MODE VOLTAGE

MAX4475 toc02

MAX4475 toc03

















VDD = 3V







VDD = 5V


50


INPUT OFFSET VOLTAGE (V)

40


30


20


10


0

-50 -40 -30 -20 -10 0 10 20 30 40 50

-50 -25 0 25 50 75 100 125

-0.5

0.5

1.5

2.5 3.5 4.5

VOS (V)

TEMPERATURE (°C)

INPUT COMMON-MODE VOLTAGE (V)



0.25


OUTPUT VOLTAGE (V)

0.20


0.15


0.10


0.05


0

OUTPUT VOLTAGE

vs. OUTPUT LOAD CURRENT

OUTPUT VOLTAGE SWING (VOH) vs. TEMPERATURE

MAX4475 toc04

VDD = 3V OR 5V VDIFF = 10mV



























VDD - VOH







VOL












































RL = 1k














RL = 10k




70


60


VDD - VOH (mV)

50


40


30


20


10


0

OUTPUT VOLTAGE SWING (VOL) vs. TEMPERATURE

MAX4475 toc05

MAX4475 toc06







































RL = 1k










RL = 10k

70


60


50


VOL (mV)

40


30


20


10


0

0 1 2 3 4 5

6 7 8 9 10

-50

-25

0 25

50 75 100 125

-50

-25

0 25

50 75 100 125

OUTPUT LOAD CURRENT (mA)

TEMPERATURE (°C)

TEMPERATURE (°C)



130


120

LARGE-SIGNAL VOLTAGE GAIN vs. OUTPUT VOLTAGE SWING


MAX4475 toc07

130


120

LARGE-SIGNAL VOLTAGE GAIN vs. OUTPUT VOLTAGE SWING


MAX4475 toc08

130


120

LARGE-SIGNAL VOLTAGE GAIN vs. OUTPUT VOLTAGE SWING


110


AV (dB)

100


90


80


70


60


RL = 2k


RL = 20k RL = 200k


VDD = 3V


110


AV (dB)

100


90


80


70


60


RL = 20k RL = 200k


RL = 2k


VDD = 3V


110


AV (dB)

100


90


80


70


60

RL = 2k

RL = 200k RL = 20k


MAX4475 toc09

VDD = 5V

RL REFERENCED TO GND

50

0 50 100 150 200 250

VOUT SWING FROM EITHER SUPPLY (mV)

RL REFERENCED TO VDD

50

0 50 100 150 200 250

VOUT SWING FROM EITHER SUPPLY (mV)

RL REFERENCED TO GND

50

0 50 100 150 200 250

VOUT SWING FROM EITHER SUPPLY (mV)


Typical Operating Characteristics (continued)

(VDD = +5V, VSS = 0V, VCM = 0V, VOUT = VDD/2, RL tied to VDD/2, input noise floor of test equipment =10nV/√Hz for all distortion measurements, TA = +25°C, unless otherwise noted.)


130


120


110


LARGE-SIGNAL VOLTAGE GAIN vs. OUTPUT VOLTAGE SWING


RL = 200k


140

MAX4475 toc10

130

120


LARGE-SIGNAL VOLTAGE GAIN vs. TEMPERATURE


MAX4475 toc11












RL = 100k



RL = 10k







































VOUT = 150mV TO 4.75V




3.0


2.5


SUPPLY CURRENT vs. TEMPERATURE


MAX4475 toc12

PER AMPLIFIER


AV (dB)

100


90


80


70


60

RL = 20k

RL = 2k


VDD = 5V

110

AVOL (dB)

100

90

80

70

60

2.0


SUPPLY CURRENT (mA)

1.5


1.0


0.5

RL REFERENCED TO VDD

50

0 50 100 150 200 250


50

-50


-25


0 25


50 75 100 125


0

-50


-25 0


25 50


75 100 125

VOUT SWING FROM EITHER SUPPLY (mV)

TEMPERATURE (°C)

TEMPERATURE (°C)



3.0


SUPPLY CURRENT (mA)

2.5


2.0


1.5


1.0


0.5


0

SUPPLY CURRENT vs. SUPPLY VOLTAGE


PER AMPLIFIER


3.0


MAX4475 toc13

SUPPLY CURRENT (mA)

2.5


2.0


1.5


1.0


0.5


0

SUPPLY CURRENT vs.OUTPUT VOLTAGE


MAX4475 toc14




VDD = 5V









VDD = 3V



















20


INPUT OFFSET VOLTAGE (V)

15


10


5


0


-5


-10


-15


-20

INPUT OFFSET VOLTAGE vs. SUPPLY VOLTAGE





















































MAX4475 toc15

2.5

3.0

3.5 4.0

4.5 5.0 5.5

0 1 2

3 4 5

2.5

3.0

3.5

4.0 4.5 5.0 5.5

SUPPLY VOLTAGE (V)

OUTPUT VOLTAGE (V)

SUPPLY VOLTAGE (V)



60

50

40

30

GAIN (dB)

20

10

0

-10

-20

-30

-40

MAX4475–MAX4478

GAIN AND PHASE vs. FREQUENCY

MAX4475 toc16


VDD = 3V OR 5V

GAIN RL = 50k

CL = 20pF

PHASE (degrees)

AV = +1000V/V


PHASE


180

144

108

72

36

0

-36

-72

-108

-144

-180


60

50

40

30

GAIN (dB)

20

10

0

-10

-20

-30

-40

MAX4488/MAX4489

GAIN AND PHASE vs. FREQUENCY

MAX4475 toc17





GAIN
















































































VDD = 3V OR 5V








RL = 50k

CL = 20pF



PH

AS

E




AV = +1000V/V









180

144

108

PHASE (degrees)

72

36

0

-36

-72

-108

-144

-180

100

1k 10k

100k 1M 10M

100M

100

1k 10k

100k 1M 10M

100M

INPUT FREQUENCY (Hz) INPUT FREQUENCY (Hz)


Typical Operating Characteristics (continued)

(VDD = +5V, VSS = 0V, VCM = 0V, VOUT = VDD/2, RL tied to VDD/2, input noise floor of test equipment =10nV/√Hz for all distortion measurements, TA = +25°C, unless otherwise noted.)

MAX4475 toc18

MAX4475–MAX4478


0

-10

-20

-30

-40

PSRR (dB)

-50

-60

-70

-80

-90

-100

-110

-120

-130

POWER-SUPPLY REJECTION RATIO vs. FREQUENCY


VDD = 3V OR 5V


1000


OUTPUT IMPEDANCE ()

100


10


1


0.1


0.01

OUTPUT IMPEDANCE vs. FREQUENCY


MAX4475 toc19

AV = +5


= +1

AV

0.001 0.1 10

1000 100,000

1 10

100 1k

10k

FREQUENCY (kHz) FREQUENCY (Hz)



VIN EQUIVALENT INPUT NOISE VOLTAGE (nVHz)

INPUT VOLTAGE-NOISE DENSITY vs. FREQUENCY


0.1Hz TO 10HzP-P NOISE

MAX4475

TOTAL HARMONIC DISTORTION PLUS NOISE

VDD = 3V OR 5V

VP-P NOISE = 260nVP-

MAX4475 toc20

25 MAX4475 toc21


P

20

vs. OUTPUT VOLTAGE SWING

MAX4475 toc22

10

AV = +1

RL = 100k

1


15

200nV/div


10


5


0

0.1


THD + N (%)

0.01


0.001


0.0001


fO = 20kHz, FILTER BW = 80kHz


fO = 3kHz, FILTER BW = 30kHz

10 100

1k 10k

100k

1s/div

0 1 2 3 4

FREQUENCY (Hz)

OUTPUT VOLTAGE (VP-P)


MAX4488/MAX4489

TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT VOLTAGE SWING

MAX4488/MAX4489 TOTAL HARMONIC DISTORTION

PLUS NOISE vs. FREQUENCY

MAX4475–MAX4478

MAX4475 toc24

TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY

MAX4475 toc23

10


1


THD + N (%)

0.1

AV = +5

RL = 100k

0.01

0.01

FILTER BW = 80kHz VOUT = 2VP-P

MAX4475 toc25

AV = +1

THD + N (%)

RL = 1k


0.01


0.001


0.0001


VDD = 3V, fO = 3kHz

VDD = +3V, fO = 20kHz FILTER BW = 80kHz


THD + N (%)

0.001


FILTER BW = 22kHz RL = 10k TO GND


AV = +10, VDD = 3V


AV = +10, VDD = 5V


RL TO VDD/2 RL TO GND


0.00001

FILTER BW = 30kHz


0.0001

R1 = 5.6k, R2 = 53k

VOUT = 2VP-P


0.001


RL TO VDD

0 1 2 3

0 5k

10k

15k

20k

0 5k 10k 15k

20k

OUTPUT VOLTAGE (VP-P)

FREQUENCY (Hz)

FREQUENCY (Hz)


Typical Operating Characteristics (continued)

(VDD = +5V, VSS = 0V, VCM = 0V, VOUT = VDD/2, RL tied to VDD/2, input noise floor of test equipment =10nV/√Hz for all distortion measurements, TA = +25°C, unless otherwise noted.)


MAX4488/MAX4489

MAX4475 toc26

TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY


MAX4475–MAX4478

LARGE-SIGNAL PULSE RESPONSE

MAX4475 toc27


MAX4475–MAX4478

SMALL-SIGNAL PULSE RESPONSE

MAX4475 toc28

1


THD + N (%)

0.1


0.01


0.001


0.0001

FILTER BW = 80kHz RL = 10k TO GND

R1 = 2.43k, R2 = 10k

VOUT = 2.75VP-P


AV = +5, VDD = 3V


AV = +5, VDD = 5V


2.5V


0.5V


0.6V


20mV/div


0.5V

0 5k

10k FREQUENCY (Hz)

15k 20k

1s/div

VDD = 3V, RL = 10k, CL = 100pF VIN = 2V

4s/div

VDD = 3V, RL = 10k, CL = 100pF VIN = 100mV PULSE



MAX4488/MAX4489

LARGE-SIGNAL PULSE RESPONSE

MAX4475 toc29


MAX4488/MAX4489

SMALL-SIGNAL PULSE RESPONSE

MAX4475 toc30


-20


MAX4477/MAX4478/MAX4489 CROSSTALK vs. FREQUENCY


VOUT

200mV/div


1.6V VOUT

50mV/div 1.5V


-30


CROSSTALK (dB)

MAX4475 toc31

-40


-50


-60


-70



1s/div


1s/div

-80


-90

10


100


1000 10k 100k 1M 10M


100M

VDD = 3V, RL = 10k, CL = 50pF VIN = 20mV PULSE, AV = +5V/V

VDD = 3V, RL = 10k, CL = 50pF VIN = 20mV PULSE, AV = +5V/V

FREQUENCY (Hz)


Pin Description

PIN


NAME


FUNCTION

MAX4475/ MAX4488

MAX4475/ MAX4488

MAX4476

MAX4477/ MAX4489

MAX4478

SOT23/TDFN

SO/µMAX

SOT23/TDFN

SO/µMAX

SO/TSSOP


1


6


1


1, 7


1, 7, 8, 14

OUT, OUTA, OUTB, OUTC, OUTD


Amplifier Output


2


4


2


4


11


VSS

Negative Supply. Connect to ground for single-supply operation


3


3


3


3, 5


3, 5, 10, 12


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


Noninverting Amplifier Input

4

2

4

2, 6

2, 6, 9, 13

IN-, INA-, INB-, INC-, IND-

Inverting Amplifier Input

6

7

6

8

4

VDD

Positive Supply


5


8





SHDN

Shutdown Input. Connect to VDD for normal operation (amplifier(s) enabled).

1, 5

5

N.C.

No Connection. Not internally connected.

EP

EP

EP

Exposed Paddle (TDFN Only). Connect to VSS.


Detailed Description

The MAX4475–MAX4478/MAX4488/MAX4489 single-

supply operational amplifiers feature ultra-low noise and distortion. Their low distortion and low noise make them ideal for use as preamplifiers in wide dynamic-range appli- cations, such as 16-bit analog-to-digital converters (see Typical Operating Circuit). Their high-input impedance and low noise are also useful for signal conditioning of high-im- pedance sources, such as piezoelectric transducers.

These devices have true rail-to-rail output operation, drive loads as low as 1k while maintaining DC accuracy, and can drive capacitive loads up to 200pF without oscillation. The input common-mode voltage range extends from

(VDD - 1.6V) to 200mV below the negative rail. The push- pull output stage maintains excellent DC characteristics, while delivering up to ±5mA of current.

The MAX4475–MAX4478 are unity-gain stable, while the MAX4488/MAX4489 have a higher slew rate and are stable for gains ≥ 5V/V. The MAX4475/MAX4488 feature a low-power shutdown mode, which reduces the supply current to 0.01µA and disables the outputs.

Low Distortion

Many factors can affect the noise and distortion that the device contributes to the input signal. The following guide- lines offer valuable information on the impact of design choices on Total Harmonic Distortion (THD).

Choosing proper feedback and gain resistor values for a particular application can be a very important factor in reducing THD. In general, the smaller the closed-loop gain, the smaller the THD generated, especially when driving heavy resistive loads. The THD of the part nor- mally increases at approximately 20dB per decade, as a function of frequency. Operating the device near or above the full-power bandwidth significantly degrades distortion.

Referencing the load to either supply also improves the part’s distortion performance, because only one of the MOSFETs of the push-pull output stage drives the output. Referencing the load to midsupply increases the part’s distortion for a given load and feedback setting. (See the Total Harmonic Distortion vs. Frequency graph in the Typical Operating Characteristics.)

For gains ≥ 5V/V, the decompensated devices MAX4488/ MAX4489 deliver the best distortion performance, since they have a higher slew rate and provide a higher amount of loop gain for a given closed-loop gain setting. Capacitive loads below 100pF do not significantly affect distortion results. Distortion performance is relatively con- stant over supply voltages.



CZ


RF


RG

VOUT


VIN

0V

Figure 1. Adding Feed-Forward Compensation



100mV

AV = +2

RF = RG = 100k

VIN

100mV/div

2s/div


VOUT

100mV/div

Figure 2a. Pulse Response with No Feed-Forward

AV = +2

RF = RG = 100k

Compensation



VIN

100mV/div


VOUT

100mV/div


2s/div

Figure 2b. Pulse Response with 10pF Feed-Forward

Compensation


Low Noise

The amplifier’s input-referred noise-voltage density is dominated by flicker noise at lower frequencies, and by thermal noise at higher frequencies. Because the thermal noise contribution is affected by the parallel combination

of the feedback resistive network (RF || RG, Figure 1), these resistors should be reduced in cases where the system bandwidth is large and thermal noise is dominant.

This noise contribution factor decreases, however, with increasing gain settings.

For example, the input noise-voltage density of the circuit with RF = 100k, RG = 11k (AV = +5V/V) is en = 14nV/√Hz, en can be reduced to 6nV/√Hz by choos- ing RF = 10k, RG = 1.1k (AV = +5V/V), at the expense of greater current consumption and potentially higher distortion. For a gain of 100V/V with RF = 100k, RG = 1.1k, the en is still a low 6nV/√Hz.

Using a Feed-Forward Compensation Capacitor, CZ

The amplifier’s input capacitance is 10pF. If the resistance seen by the inverting input is large (feedback network), this can introduce a pole within the amplifier’s bandwidth resulting in reduced phase margin. Compensate the reduced phase margin by introducing a feed-forward

capacitor (CZ) between the inverting input and the out- put (Figure 1). This effectively cancels the pole from the inverting input of the amplifier. Choose the value of CZ as follows:

CZ = 10 x (RF / RG) [pF]

In the unity-gain stable MAX4475–MAX4478, the use of a proper CZ is most important for AV = +2V/V, and AV = -1V/V. In the decompensated MAX4488/MAX4489, CZ is most important for AV = +10V/V. Figures 2a and 2b show transient response both with and without CZ.

Using a slightly smaller CZ than suggested by the formula above achieves a higher bandwidth at the expense of reduced phase and gain margin. As a general guideline,

consider using CZ for cases where RG || RF is greater than 20k (MAX4475–MAX4478) or greater than 5k (MAX4488/MAX4489).

Applications Information

The MAX4475–MAX4478/MAX4488/MAX4489 combine

good driving capability with ground-sensing input and rail-to-rail output operation. With their low distortion and low noise, they are ideal for use in ADC buffers, medical instrumentation systems and other noise-sensitive appli- cations.



VIN

2V/div


0V


VOUT

2V/div


40s/div

AV = +1 VDD = +5V RL = 10k

Figure 3. Overdriven Input Showing No Phase Reversal


















































































5V


VOUT

1V/div


0V


20s/div


Figure 4. Rail-to-Rail Output Operation


Ground-Sensing and Rail-to-Rail Outputs

The common-mode input range of these devices extends below ground, and offers excellent common-mode rejec- tion. These devices are guaranteed not to undergo phase reversal when the input is overdriven (Figure 3).

Figure 4 showcases the true rail-to-rail output operation of the amplifier, configured with AV = 5V/V. The output swings to within 8mV of the supplies with a 10k load, making the devices ideal in low-supply voltage applica-

tions.

Power Supplies and Layout

The MAX4475–MAX4478/MAX4488/MAX4489 operate

from a single +2.7V to +5.5V power supply or from dual supplies of ±1.35V to ±2.75V. For single-supply opera- tion, bypass the power supply with a 0.1µF ceramic


0 to +2.5V OUTPUT

U2

MAX4475AUA

6

3

REF

OUT AGND

VDD

U1

MAX5541ESA

SERIAL

INTERFACE SCLK

+5V


7

Typical Application Circuit


CS

+5V

+2.5V


4 8


SHDN


7.15k

1%

1/2 MAX4477

5

3.83k 13.7k

1% 1%

1

220pF

8

3

2

DGND

DIN

Typical Operating Circuit


470pF

5V


0.1F


3.09k

1%

7.87k

1%

220pF


2 4

1/2 MAX4477

220pF


6


10.0k

1%

10.0k

1%


15.0k

1%

10.0k

1%

7

220pF

capacitor placed close to the VDD pin. If operating from dual supplies, bypass each supply to ground.

Good layout improves performance by decreasing the amount of stray capacitance and noise at the op amp’s inputs and output. To decrease stray capacitance, mini- mize PC board trace lengths and resistor leads, and place external components close to the op amp’s pins.

Typical Application Circuit

The Typical Application Circuit shows the sin- gle MAX4475 configured as an output buffer for the MAX5541 16-bit DAC. Because the MAX5541 has an unbuffered voltage output, the input bias current of the op amp used must be less than 6nA to maintain 16-bit accuracy. The MAX4475 has an input bias current of only 150pA (max), virtually eliminating this as a source

of error. In addition, the MAX4475 has excellent open- loop gain and common-mode rejection, making this an excellent output buffer amplifier.

DC-Accurate Lowpass Filter

The MAX4475–MAX4478/MAX4488/MAX4489 offer a

unique combination of low noise, wide bandwidth, and high gain, making them an excellent choice for active filters up to 1MHz. The Typical Operating Circuit shows the dual MAX4477 configured as a 5th order Chebyschev filter with a cutoff frequency of 100kHz. The circuit is implemented in the Sallen-Key topology, making this a DC-accurate filter.


Pin Configurations


7

2

8

1

TOP VIEW TOP VIEW

+

+

N.C. INA- INA+ VSS

SHDN VDD

5

4

6

3

7

2

8

MAX4475 MAX4488

OUT N.C.

OUTA INA- INA+ VSS

VDD OUTB INB- INB+

5

4

6

3

MAX4477 MAX4489

SO/MAX SO/MAX



TOP VIEW


OUTA INA- INA+ VDD INB+

INB- OUTB


SO/TSSOP


OUTD IND- IND+


+


MAX4478


1

14

2

13

3

12

4

11

5

10

6

9

7

8



VSS INC+ INC- OUTC


TOP VIEW


OUT


VSS


IN+



+


1


2

MAX4475 MAX4488


3


SOT23-6


VDD


5

6

SHDN


4

IN-


TOP VIEW



VDD

SHDN IN-

6

5


4



MAX4475 MAX4488


EP

+ 1

2


3



OUT

VSS

IN+

TDFN


TOP VIEW


OUT


VSS


+

6

1

VDD

N.C.

IN-

VDD


2

MAX4476

5 N.C.


TOP VIEW

6 5 4


4

3

MAX4476


EP

IN+ IN-


1 2 3

+

OUT

VSS

IN+

SOT23-6



TDFN


Ordering Information

PART

TEMP RANGE

PIN- PACKAGE

TOP MARK

MAX4475AUT+T

-40°C to +125°C

6 SOT23

AAZV

MAX4475AUA+

-40°C to +125°C

8 µMAX

MAX4475ASA+

-40°C to +125°C

8 SO

MAX4475ATT+T

-40°C to +125°C

6 TDFN-EP*

+ADD

MAX4475AUT/V+T

-40°C to +125°C

6 SOT23

+ACQQ

MAX4476AUT+T

-40°C to +125°C

6 SOT23

AAZX

MAX4476ATT+T

-40°C to +125°C

6 TDFN-EP*

+ADF

MAX4477AUA+

-40°C to +125°C

8 µMAX

MAX4477AUA+

-40°C to +125°C

8 µMAX

MAX4477AUA/V+T

-40°C to +125°C

8 µMAX

+AA/V

MAX4477ASA+

-40°C to +125°C

8 SO

MAX4478AUD+

-40°C to +125°C

14 TSSOP

MAX4478AUD/V+

-40°C to +125°C

14 TSSOP

MAX4478ASD+

-40°C to +125°C

14 SO

MAX4488AUT+T

-40°C to +125°C

6 SOT23

AAZW

MAX4488AUA+

-40°C to +125°C

8 µMAX

MAX4488ASA+

-40°C to +125°C

8 SO

MAX4488ATT+T

-40°C to +125°C

6 TDFN-EP*

+ADE

MAX4489AUA+

-40°C to +125°C

8 µMAX

MAX4489AUA/V+T

-40°C to +125°C

8 µMAX

MAX4489ASA+

-40°C to +125°C

8 SO

+Denotes a lead(Pb)-free/RoHS-compliant package.

*EP = Exposed pad (connect to VSS).

/V denotes an automotive qualified part.

T = Tape and reel.

Chip Information

PROCESS: BiCMOS


Selector Guide


PART

GAIN BW (MHz)

STABLE GAIN (V/V)

NO. OF AMPS

SHDN

MAX4475

10

1

1

Yes

MAX4476

10

1

1

MAX4477

10

1

2

MAX4478

10

1

4

MAX4488

42

5

1

Yes

MAX4489

42

5

2


Revision History

REVISION NUMBER

REVISION DATE

DESCRIPTION

PAGES CHANGED

4

12/09

Added lead-free designations and an automotive part to the Ordering Information and added input current spec in Absolute Maximum Ratings section

1, 2, 13

5

7/10

Added /V designation to the MAX4475 product and soldering temperature

1, 2

6

6/12

Added /V designation for MAX4489.

13

7

1/18

Added AEC statement to Features section

1

8

7/18

Updated Ordering Information table

14

9

7/18

Updated Absolute Maximum Rating and Package Information

2, 14

10

8/18

Updated Package Information section

2–4

11

4/19

Updated General Description and Ordering Information section

1, 16


For pricing, delivery, and ordering information, please visit Maxim Integrated’s online storefront at https://www.maximintegrated.com/en/storefront/storefront.html.


Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.

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Authorized Distributor


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Maxim Integrated:

MAX4488AUT+T MAX4475ASA+ MAX4475AUA+ MAX4477ASA+ MAX4477AUA+ MAX4478AUD+ MAX4489AUA+ MAX4475AUT+T MAX4475ASA+T MAX4475ATT+T MAX4475AUA+T MAX4476ATT+T MAX4477ASA+T MAX4477AUA+T MAX4478ASD+ MAX4478ASD+T MAX4478AUD+T MAX4488ASA+ MAX4488ASA+T MAX4488ATT+T MAX4488AUA+ MAX4488AUA+T MAX4489ASA+ MAX4489ASA+T MAX4489AUA+T MAX4477ASA MAX4477ASA-T MAX4477AUA MAX4477AUA-T MAX4478ASD MAX4478ASD-T MAX4475AUT/V+T MAX4478AUD/V+ MAX4478AUD/V+T MAX4478AUD MAX4478AUD-T MAX4489ASA MAX4489ASA-T MAX4489AUA MAX4489AUA-T MAX4476AUT+T MAX4477AUA/V+ MAX4477AUA/V+T