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MAX40242 20V, Low Input Bias-Current, Low-Noise, Dual Op Amp


General Description

The MAX40242 provides a combination of high voltage, low noise, low input bias current in a dual channel and features rail-to-rail at the output.

This dual amplifier operates over a wide supply voltage range from a single 2.7V to 20V supply or split ±1.35V to ±10V supplies and consumes only 1.2mA quiescent supply current per channel.

The MAX40242 is a unity-gain stable amplifier with a gain-bandwidth product of 10MHz. The device outputs drive up to 200pF load capacitor without any external isolation resistor compensation.

The MAX40242 is available in 8-thin wafer-level packages (WLPs) and is rated for operation over the

-40°C to +125°C automotive temperature range.

Applications


Typical Application Circuit

Benefits and Features


Ordering Information appears at end of data sheet.


VDD


PHOTODIODE


IN-


OUT

PHOTODIODE


IN+

IN-


REF

OUT

IN+


MAX40242

REF


19-100357 Rev 0; 6/18


Absolute Maximum Ratings

Supply Voltage (VDD to VSS) ................................-0.3V to +22V

All Other Pins ................................ (VSS - 0.3V) to (VDD + 0.3V)

Short-Circuit Duration to VDD or VSS...................................... 1s

Continuous Input Current (Any Pins) ...............................±20mA

Differential Input Voltage ...................................................... ±6V

Continuous Power Dissipation (TA = +70°C)

8-THIN WLP (derate 11.4mW/°C above +70°C) .........912mW


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


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 Thermal Characteristics (Note 1)

8-THIN WLP

Junction-to-Ambient Thermal Resistance (θJA) .....87.71°C/W

Junction-to-Case Thermal Resistance (θJC) ..............NA°C/W

Note 1: 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.


Electrical Characteristics

(VDD = 10V, VSS = 0V, VIN+ = VIN- = VDD/2, RL = 10kΩ to VDD/2, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2)


PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

POWER SUPPLY

Supply Voltage Range

VDD

Guaranteed by PSRR

2.7


20

V


Power-Supply Rejection Ratio


PSRR

VDD = 2.7V to 20V, VCM = 0V

TA = +25ºC

106 130


dB

-40ºC ≤ TA ≤ +125ºC

100


Quiescent Current Per Amplifier


IDD


RLOAD = infinity

TA = +25ºC


1.2

1.6


mA

-40ºC ≤ TA ≤ +125ºC

1.8


Power-Up Time

tON

RLOAD = 10kΩ to VDD/2, CLOAD = 20pF,

VOUT reaches VDD/2 to 1%


20


µs

DC CHARACTERISTICS

Input Common-Mode Range

VCM

Guaranteed by CMRR test

VSS - 0.05


VDD - 1.5

V


Common-Mode Rejection Ratio


CMRR

VCM = VSS - 0.05V to VDD - 1.5V

TA = +25ºC

94 111


dB

-40ºC ≤ TA ≤ +125ºC

90


Input Offset Voltage


VOS

TA = +25ºC


50

600


µV

-40ºC ≤ TA ≤ +125ºC

800

Input Offset Voltage Drift (Note 3)

TC VOS



0.25

2.5

µV/ºC


Input Bias Current (Note 3)


IB

TA = +25ºC

0.02 2


pA

-40ºC ≤ TA ≤ +85ºC

15

-40ºC ≤ TA ≤ +125ºC

75


Electrical Characteristics (continued)

(VDD = 10V, VSS = 0V, VIN+ = VIN- = VDD/2, RL = 10kΩ to VDD/2, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2)


PARAMETER

SYMBOL

CONDITIONS

MIN TYP MAX

UNITS


Input Offset Current (Note 3)


IOS

TA = +25°C

0.04 1


pA

-40°C ≤ TA ≤ +85°C

10

-40°C ≤ TA ≤ +125°C

25


Open Loop Gain


AVOL

250mV ≤ VOUT

≤ VDD - 250mV

TA = +25°C

134 145


dB

-40°C ≤ TA ≤ +125°C

129


Input Resistance


RIN

Differential

50


MΩ

Common mode

200

Output Short-Circuit Current (Note 3)


To VDD or VSS

Noncontinuous (1s)

95

mA


Output Voltage Low


VOL

VOUT - VSS, RLOAD = 10KΩ to VDD/2, TA = +25°C

11 15


mV

VOUT - VSS, RLOAD = 10KΩ to VDD/2,

-40°C < TA < 125°C

25

VOUT - VSS, RLOAD = 2KΩ to VDD/2, TA = +25°C

47 60

VOUT - VSS, RLOAD = 2KΩ to VDD/2,

-40°C < TA < 125°C

85


Output Voltage High


VOH

VOUT - VSS, RLOAD = 10KΩ to VDD/2, TA = +25°C


20 26


mV

VOUT - VSS, RLOAD = 10KΩ to VDD/2,

-40°C < TA < 125°C


37

VOUT - VSS, RLOAD = 2KΩ to VDD/2, TA = +25°C


80 100

VOUT - VSS, RLOAD = 2KΩ to VDD/2,

-40°C < TA < 125°C


135

AC CHARACTERISTICS

Input Voltage-Noise Density

en

f = 1kHz

5

nV/√Hz

Input Voltage Noise


0.1Hz ≤ f ≤ 10Hz

1.6

µVP-P

Input Current-Noise Density

IN

f = 1kHz

0.3

pA/√Hz

Input Capacitance

CIN


4

pF

Gain-Bandwidth Product

GBW


10

MHz

Phase Margin

PM

CLOAD = 20pF

60

°

Slew Rate

SR

AV = 1V/V, VOUT = 2VP-P, 10% to 90%

8

V/µs

Large-Signal Bandwidth

BW

RLOAD = 10KΩ to VDD/2, CLOAD = 20pF, AV = 1V/V

1

MHz

Capacitive Loading

CLOAD

No sustained oscillation, AV = 1V/V

200

pF


Crosstalk

XT

RLOAD = 2KΩ to VDD/2, CLOAD = 20pF, VOUT = 5VP-P, f = 100kHz


-98


dB


Electrical Characteristics (continued)

(VDD = 10V, VSS = 0V, VIN+ = VIN- = VDD/2, RL = 10kΩ to VDD/2, TA = -40°C to +125°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2)


PARAMETER

SYMBOL

CONDITIONS

MIN TYP MAX

UNITS


Total Harmonic Distortion Plus Noise


THD+N

VOUT = 2VP-P, AV = +1V/V

f = 1kHz

-124


dB

f = 20kHz

-100


EMI Rejection Ratio


EMIRR


VRF_PEAK = 100mV

f = 400MHz

35


dB

f = 800MHz

40

f = 1800MHz

50

f = 2400MHz

57

Settling Time


To 0.1%, VOUT = 2V step, AV = -1V/V

2

µs

Note 2: All devices are production tested at TA = +25°C. Specifications over temperature are guaranteed by design.

Note 3: Guaranteed by design.


Typical Operating Characteristics

(VDD = 10V, VSS = 0V, outputs have RL = 10kΩ to VDD/2. TA = +25°C, unless otherwise specified.)



INPUT OFFSET VOLTAGE HISTOGRAM

35 toc01


INPUT OFFSET VOLTAGE DRIFT HISTOGRAM

35 toc02


1800

SUPPLY CURRENT PER AMPLIFIER vs. TEMPERATURE


toc03

HISTOGRAM

30


OCCURRENCE N (%)

25


20


15


10


5

HISTOGRAM

30


OCCURRENCE N (%)

25


20


15


10


5


1500


SUPPLY CURRENT PER AMPLIFIER (μA)

1200


900


600


300

VIN = VDD/2 NO LOAD


VDD = 10V

VDD = 20V

VDD = 15V


VDD = 5.5V


VDD = 2.7V


0

-200 -150 -100 -50 0 50 100 150 200

INPUT OFFSET VOLTAGE (μV)


0

-500 -400 -300 -200 -100 0 100 200 300 400 500

INPUT OFFSET VOLTAGE DRIFT (nV/°C)


0

-50 -25 0 25 50 75 100 125 150

TEMPERATURE (°C)



10

0

INPUT OFFSET VOLTAGE (μV)

-10

-20

-30

-40

-50

-60

-70


INPUT OFFSET VOLTAGE

vs. INPUT COMMON-MODE VOLTAGE vs. TEMPERATURE


VIN = VDD/2 RLOAD = 10k to VDD/2

TA = -40°C


TA = +25°C


TA = +85°C


toc04


600


INPUT BIAS CURRENT (pA)

400


200


0

INPUT BIAS CURRENT(IB+)

vs. INPUT COMMON MODE VOLTAGE vs. TEMPERATURE


TA = +125°C


TA = +85°C

TA = 25°C


toc05


INPUT BIAS CURRENT (pA)

600


400


200


0

INPUT BIAS CURRENT(IB-)

vs. INPUT COMMON MODE VOLTAGE vs. TEMPERATURE


TA = 125°C


TA = 85°C

TA = +25°C


toc06

-80

-90

TA = +125°C


-1 1 3 5 7 9

INPUT COMMON-MODE VOLTAGE (V)


-200


0 2 4 6 8 10

INPUT COMMON MODE VOLTAGE VCM (V)


-200


0 2 4 6 8 10

INPUT COMMON MODE VOLTAGE VCM (V)



COMMON-MODE REJECTION RATIO (dB)

140


120


100


80


60


40


20

COMMON-MODE REJECTION RATIO vs. TEMPERATURE



















































toc07


POWER-SUPPLY REJECTION RATIO (dB)

150


130


110


90


70


50

POWER-SUPPLY REJECTION RATIO vs. TEMPERATURE












































toc08


0

-50 -25 0 25 50 75 100 125

TEMPERATURE (°C)


30

-50 -25 0 25 50 75 100 125

TEMPERATURE (°C)


Typical Operating Characteristics (continued)

(VDD = 10V, VSS = 0V, outputs have RL = 10kΩ to VDD/2. TA = +25°C, unless otherwise specified.)



140


AC COMMON MODE REJECTION RATIO vs. FREQUENCY

toc09


AC POWER SUPPLY REJECTION RATIO (dB)

140


AC PSRR

vs. FREQUENCY


toc10


140


AV = 10V/V

GAIN AND PHASE vs. FREQUENCY (RL= 10k)


toc11


250


120


AC CMRR (dB)

100


80


60


40


20


0


120


100


80


60


40


20

120


100


GAIN (dB)

80


60


40


20


0


-20

PHASE CURVE IS REFERRED TO DEGREE UNITS ON AXIS FAR RIGHT


PHASE GAIN

200

150

100

50

0

-50

-100

-150

-200

1E+1 1E+2 1E+3 1E+4 1E+5 1E+6 1E+7 1E+8 FREQUENCY (Hz)

1E+1 1E+2 1E+3 1E+4 1E+5 1E+6 1E+7 1E+8 FREQUENCY (Hz)

0.01 0.1 1 10 100 1000 10000 100000

FREQUENCY (kHz) Thousands



10


SMALL SIGNAL RESPONSEL (dB)

5


0


-5


-10


-15


-20

SMALL-SIGNAL RESPONSE vs. FREQUENCY




















VIN = 100mVP-P


































































































toc12


10


LARGE SIGNAL RESPONSE (dB)

5


0


-5


-10


-15


-20

LARGE-SIGNAL RESPONSE vs. FREQUENCY






















VIN = 2VP-P












































































































toc13

INPUT VOLTAGE-NOISE DENSITY vs. FREQUENCY

50

INPUT VOLTAGE-NOISE DENSITY (nV/√Hz)

45

40

35

30

25

20

15

10

5

0


toc14

1E+1 1E+2 1E+3 1E+4 1E+5 1E+6 1E+7 1E+8 FREQUENCY (Hz)

1E+1 1E+2 1E+3 1E+4 1E+5 1E+6 1E+7 1E+8 FREQUENCY (Hz)

10 100 1000 10000 100000

FREQUENCY (Hz)



INPUT VOLTAGE NOISE 0.1Hz TO 10Hz NOISE

INPUT CURRENT-NOISE DENSITY vs. FREQUENCY

2.E-6


2.E-6


1.E-6


5.E-7


VOLTS

0.E+0


-5.E-7


-1.E-6


-2.E-6


-2.E-6

toc15


eN = 21.1621µVP-P


0 4 8 12 16 20 24 28 32

4s/div

2

INPUT CURRENT-NOISE DENSITY (pA/√Hz)

1.8

1.6

1.4

1.2

1

0.8

0.6

0.4

0.2

0

toc16

































































































































































10 100 1000 10000 100000

FREQUENCY (Hz)


Typical Operating Characteristics (continued)

(VDD = 10V, VSS = 0V, outputs have RL = 10kΩ to VDD/2. TA = +25°C, unless otherwise specified.)



OUTPUT VOLTAGE HIGH VOH (VDD - VOUT) (mV)

1000

OUTPUT VOTLAGE HIGH

vs. OUTPUT SOURCE CURRENT


toc17


OUTPUT VOLTAGE LOW VOL (VOUT - VSS) (mV)

600

OUTPUT VOTLAGE LOW vs. OUTPUT SINK CURRENT


TA = 125°C

toc18

SMALL-SIGNAL RESPONSE vs. TIME


toc19


750


500


TA = 85°C TA = 125°C


500


400


300


TA = 85°C

VIN

50mV/div



250


0


TA = -40°C


TA = 25°C

200


100


0


TA = -40°C


TA = 25°C


VOUT

50mV/div

0 4 8 12 16 20

SOURCE CURRENT (mA)

0 4 8 12 16 20

SINK CURRENT (mA)



LARGE-SIGNAL RESPONSE vs. TIME


toc20


VIN


100


80

STABILITY

vs. CAPACITIVE LOAD AND RESISTIVE LOAD


STABLE


toc21


VOUTN VINSIDE

VBACKUP

1V/div

60

RESISTIVE LOAD (k)

UNSTABLE


40



1μs/div


VOUT

1V/div

20


0

10 100 1000 10000

CAPACITIVE LOAD (pF)



100

STABILITY

vs. CAPACITIVE LOAD AND ISOLATION RESISTOR toc22


ISOLATION RESISTANCE RISO ()

10


UNSTABLE

1


0.1

STABLE


0.01

100 1000 10000 100000

CAPACITIVE LOAD (pF)


Typical Operating Characteristics (continued)

(VDD = 10V, VSS = 0V, outputs have RL = 10kΩ to VDD/2. TA = +25°C, unless otherwise specified.)



2VP-P INPUT

TOTAL HARMONIC DISTORTION+NOISE vs. FREQUENCY

TOTAL HARMONIC DISTORTION+NOISE vs. INPUT FREQUENCY

TOTAL HARMONIC DISTORTION + NOISE (dB)

0

-10

-20

-30

-40

-50

-60

-70

-80

-90

-100

-110

-120

toc24

0


TOTAL HARMONIC DISTORTION + NOISE (dB)

-20


-40


-60


-80


-100


-120


RLOAD

vs. AMPLITUDE


= 10k


1kHz INPUT FREQUENCY


20kHz INPUT FREQUENCY

toc25

10 100 1000 10000 100000

FREQUENCY (Hz)

0 2 4 6 8 10

FREQUENCY (Hz)


CROSSTALK vs. FREQUENCY

0


toc26


100

EMIRR

vs. FREQUENCY


toc27


EMI REJECTION RATIO (dB)

-20 80


CROSSTALK (dB)

-40

60

-60

40

-80


-100 20


-120

1E+1 1E+2 1E+3 1E+4 1E+5 1E+6 1E+7 1E+8 FREQUENCY (Hz)

0

10 100 1000 10000

FREQEUNCY (MHz)


+

Pin Configuration



1

2

3

4


A

INA-

OUTA

OUTB

INB-


MAX40242


B

INA+

VDD

VSS

INB+


WLP


Bump Description


BUMP (WLP)

NAME

FUNCTION

A1

INA-

Channel A Negative Input

A2

OUTA

Channel A Output

A3

OUTB

Channel B Output

A4

INB-

Channel B Negative Input

B1

INA+

Channel A Positive Input

B2

VDD

Positive Supply Voltage

B3

VSS

Negative Supply Voltage. Connect VSS to ground if single supply is used.

B4

INB+

Channel B Positive Input


Detailed Description

Combining high input impedance, low input bias current, wide bandwidth, and fast settling time, the MAX40242 is an ideal amplifier for driving precision analog-to-digital inputs and buffering digital-to-analog converter outputs.

Input Bias Current

The MAX40242 features a high-impedance CMOS input stage and a special ESD structure that allows low input bias current operation at low-input, common-mode voltages. Low input bias current is useful when interfacing with high-ohmic or capacitive sensors and is beneficial for designing transimpedance amplifiers for photodiode sensors. This makes the device ideal for ground- referenced medical and industrial sensor applications.

Integrated EMI Filter

Electromagnetic interference (EMI) noise occurs at higher frequency that results in malfunction or degradation of electrical equipment.

The MAX40242 has an input EMI filter to avoid the output from getting affected by radio frequency interference. The EMI filter, composed of passive devices, presents significant higher impedance to higher frequencies.

High Supply Voltage Range

The device features 1.2mA current consumption per channel and a voltage supply range from either 2.7V to 20V single supply or ±1.35V to ±10V split supply.


Typical Application Circuit

High-Impedance Sensor Application

High impedance sources like pH sensor, photodiodes in applications require negligible input leakage currents to the input transimpedance/buffer structure. The MAX40242 benefits with clean and precise signal conditioning due to its input structure.

The device interfaces to both current-output sensors (photodiodes) (Figure 1), and high-impedance voltage sources (piezoelectric sensors). For current output sensors, a transimpedance amplifier is the most noise- efficient method for converting the input signal to a voltage. High-value feedback resistors are commonly chosen to create large gains, while feedback capaci- tors help stabilize the amplifier by cancelling any poles introduced in the feedback loop by the highly capacitive sensor or cabling. A combination of low-current noise and low-voltage noise is important for these applications. Take care to calibrate out photodiode dark current if DC accuracy is important. The high bandwidth and slew rate also allow AC signal processing in certain medical photodiode sensor applications such as pulse-oximetry. For voltage-output sensors, a noninverting amplifier is typically used to buffer and/or apply a small gain to the

input voltage signal. Due to the extremely high imped- ance of the sensor output, a low input bias current with minimal temperature variation is very important for these applications.

Transimpedance Amplifier

As shown in Figure 1, the noninverting pin is biased at 2V with C2 added to bypass high-frequency noise. This bias voltage to reverse biases the photodiode D1 at 2V which is often enough to minimize the capacitance across the junction. Hence, the reverse current (IR) produced by the photodiode as light photons are incident on it, a proportional voltage is produced at the output of the amplifier by the given relation:


VOUT IR R1

The addition of C1 is to compensate for the instability caused due to the additional capacitance at the input (junction capacitance Cj and input capacitance of the op amp CIN), which results in loss of phase margin. More information about stabilizing the transimpedance amplifier can be found in Application Note 5129: Stabilize Your Transimpedance Amplifier.


C1 15nF



R1 100kΩ


+5V


MAX40242


5V

D1


R2 30kΩ


R3 20kΩ

C2 10nF



Figure 1. High-Impedance Source/Sensor Preamp Application



PART


TEMP RANGE

PIN-

PACKAGE

TOP MARK

MAX40242ANA+

-40ºC to +125ºC

8-THIN WLP

+AAN

Ordering Information


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


Chip Information

PROCESS: BiCMOS

Package Information

PACKAGE TYPE

PACKAGE CODE

OUTLINE NO.

LAND PATTERN NO.

8-THIN WLP

N80D1+1

21-100280

Apps Note 1891

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.


Revision History


REVISION NUMBER

REVISION DATE

DESCRIPTION

PAGES CHANGED

0

6/18

Initial release


For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.


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.

Mouser Electronics


Authorized Distributor


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MAX40242ANA+