EVALUATION KIT AVAILABLE MAX44242 20V, Low Input Bias-Current, Low-Noise, Dual Op Amplifier General Description Benefits and Features The MAX44242 provides a combination of high voltage, low noise, low input bias current in a dual channel and features rail-to-rail at the output. 2.7V to 20V Single Supply or 1.35V to 10V Dual Supplies 0.5pA (max) Input Bias Current 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. 5nV/Hz Input Voltage Noise 10MHz Bandwidth 8V/s Slew Rate Rail-to-Rail Output The MAX44242 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 MAX44242 is available in 8-pin SOT23 and MAXM packages and is rated for operation over the -40C to +125C automotive temperature range. Integrated EMI Filters 1.2mA Supply Current per Amplifier Ordering Information appears at end of data sheet. Applications Chemical Sensor Interface Photodiode Sensor Interface Medical Pulse Oximetry Industrial: Process and Control Precision Instrumentation MAX is a registered trademark of Maxim Integrated Products, Inc. Typical Application Circuit VDD PHOTODIODE INPHOTODIODE OUT IN- IN+ OUT REF IN+ MAX44242 19-6827 Rev 2; 4/18 REF MAX44242 20V, Low Input Bias-Current, Low-Noise, Dual Op Amplifier 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 = +70C) 8-Pin SOT23 (derate 5.1mW/C above +70C)........408.2mW 8-Pin MAX (derate 4.5mW/C above +70C).............362mW Operating Temperature Range.......................... -40C to +125C Junction Temperature.......................................................+150C Storage Temperature Range............................. -65C to +150C Lead Temperature (soldering, 10s).................................. +300C 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) SOT23 Junction-to-Ambient Thermal Resistance (JA).........196C/W Junction-to-Case Thermal Resistance (JC)................70C/W MAX Junction-to-Ambient Thermal Resistance (JA).........221C/W Junction-to-Case Thermal Resistance (JC)................42C/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 = 10k to VDD/2, TA = -40C to +125C, unless otherwise noted. Typical values are at TA = +25C.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 20 V POWER SUPPLY Supply Voltage Range Power-Supply Rejection Ratio VDD PSRR Quiescent Current Per Amplifier IDD Power-Up Time tON Guaranteed by PSRR VDD = 2.7V to 20V, VCM = 0V RLOAD = infinity 2.7 TA = +25C 106 -40C TA +125C 100 TA = +25C 130 1.2 -40C TA +125C dB 1.6 1.8 20 mA s DC CHARACTERISTICS Input Common-Mode Range Common-Mode Rejection Ratio Input Offset Voltage Input Offset Voltage Drift (Note 3) VCM CMRR VOS Guaranteed by CMRR test VCM = VSS - 0.05V to VDD - 1.5V TA = +25C TC VOS www.maximintegrated.com IB TA = +25C 94 -40C TA +125C 90 VDD - 1.5 111 50 -40C TA +125C TA = +25C Input Bias Current (Note 3) VSS - 0.05 V dB 600 800 0.25 2.5 0.02 0.5 -40C TA +85C 10 -40C TA +125C 50 V V/C pA Maxim Integrated 2 MAX44242 20V, Low Input Bias-Current, Low-Noise, Dual Op Amplifier Electrical Characteristics (continued) (VDD = 10V, VSS = 0V, VIN+ = VIN- = VDD/2, RL = 10k to VDD/2, TA = -40C to +125C, unless otherwise noted. Typical values are at TA = +25C.) (Note 2) PARAMETER SYMBOL CONDITIONS MIN TA = +25C Input Offset Current (Note 3) IOS Open Loop Gain AVOL Input Resistance RIN Output Short-Circuit Current TYP MAX 0.04 0.5 -40C TA +85C 10 -40C TA +125C 25 250mV VOUT VDD - 250mV TA = +25C 134 -40C TA +125C 129 145 Differential 50 Common mode 200 To VDD or VSS Output Voltage Low VOL VOUT - VSS Output Voltage High VOH VDD - VOUT Noncontinuous UNITS pA dB M 95 mA RLOAD = 10k to VDD/2 25 RLOAD = 2k to VDD/2 85 RLOAD = 10k to VDD/2 37 RLOAD = 2k to VDD/2 135 mV mV AC CHARACTERISTICS Input Voltage-Noise Density en Input Voltage Noise Input Current-Noise Density Input Capacitance Gain-Bandwidth Product IN f = 1kHz 5 nV/Hz 0.1Hz f 10Hz 1.6 VP-P f = 1kHz 0.3 pA/Hz CIN 4 pF GBW 10 MHz Phase Margin PM CLOAD = 20pF 60 deg Slew Rate SR AV = 1V/V, VOUT = 2VP-P, 10% to 90% 8 V/s 200 pF Capacitive Loading CLOAD No sustained oscillation, AV = 1V/V Total Harmonic Distortion Plus Noise THD+N VOUT = 2VP-P, AV = +1V/V EMI Rejection Ratio Settling Time EMIRR VRF_PEAK = 100mV f = 1kHz -124 f = 20kHz -100 f = 400MHz 35 f = 900MHz 40 f = 1800MHz 50 f = 2400MHz 57 To 0.01%, VOUT = 2V step, AV = -1V/V dB dB 1 s Note 2: All devices are production tested at TA = +25C. Specifications over temperature are guaranteed by design. Note 3: Guaranteed by design. www.maximintegrated.com Maxim Integrated 3 MAX44242 20V, Low Input Bias-Current, Low-Noise, Dual Op Amplifier Typical Operating Characteristics (VDD = 10V, VSS = 0V, outputs have RL = 10k to VDD/2. TA = +25C, unless otherwise specified.) toc01 toc02 25 HISTOGRAM toc03 HISTOGRAM SUPPLY CURRENT PER AMPLIFIER ( A) 16 20 OCCURRENCE N (%) OCCURRENCE N (%) 14 12 10 8 6 15 10 4 5 2 0 VDD = 20V 1200 VDD = 10V TA = +125C TA = +85C TA = +25C -60 -80 -100 150 100 TA = +105C 0 TA = -40C -120 TA = +125C 200 50 -50 -140 TA = +25C 1 3 5 7 9 TA = +85C 2 4 6 8 75 100 150 125 toc06 120 100 80 60 40 20 10 -50 -25 0 25 50 75 100 125 TEMPERATURE (C) POWER-SUPPLY REJECTION RATIO vs. TEMPERATURE AC CMRR vs. FREQUENCY toc07 toc08 140 130 120 110 100 AC CMRR (dB) POWER-SUPPLY REJECTION RATIO (dB) 50 140 INPUT COMMON-MODE VOLTAGE (V) 150 25 0 0 INPUT COMMON-MODE VOLTAGE (V) 0 COMMON-MODE REJECTION RATIO vs. TEMPERATURE -100 -1 -25 TEMPERATURE (C) toc05 250 -40 -50 COMMON-MODE REJECTION RATIO (dB) -20 VDD = 2.7V 1000 600 300 INPUT BIAS CURRENT (pA) 0 VDD = 5.5V 1100 INPUT BIAS CURRENT vs. INPUT COMMON-MODE VOLTAGE vs. TEMPERATURE toc04 VIN = VDD/2 10k VDD = 15V 900 -600 -400 -200 0 200 400 INPUT OFFSET VOLTAGE DRIFT (nV/C) INPUT OFFSET VOLTAGE vs. INPUT COMMON-MODE VOLTAGE vs. TEMPERATURE 20 VIN = VDD/2 NO LOAD 1300 0 -250 -200 -150 -100 -50 0 50 100 150 200 250 INPUT OFFSET VOLTAGE ( V) INPUT OFFSET VOLTAGE ( V) SUPPLY CURRENT PER AMPLIFIER vs. TEMPERATURE INPUT OFFSET VOLTAGE DRIFT HISTOGRAM INPUT OFFSET VOLTAGE HISTOGRAM 90 80 60 70 40 50 20 0 30 -50 -25 0 25 50 75 TEMPERATURE (C) www.maximintegrated.com 100 125 1 100 10000 1000000 FREQUENCY (Hz) Maxim Integrated 4 MAX44242 20V, Low Input Bias-Current, Low-Noise, Dual Op Amplifier Typical Operating Characteristics (continued) (VDD = 10V, VSS = 0V, outputs have RL = 10k to VDD/2. TA = +25C, unless otherwise specified.) AC PSRR vs. FREQUENCY 120 AVOL vs. FREQUENCY toc09 toc10 SMALL-SIGNAL RESPONSE vs. FREQUENCY 10 toc11 130 SMALL-SIGNAL RESPONSE (dB) 110 100 AVOL (dB) AC PSRR (dB) 90 80 60 70 50 30 10 40 -10 20 -30 10 1,000 100,000 1,000 FREQUENCY (Hz) -5 -10 -15 -20 -25 2VP-P Input 100,000 1,000 100,000 10,000,000 FREQUENCY (Hz) 0.1 Hz to 10 Hz PEAK TO PEAK NOISE toc14 toc13 VOUTN 25 VINSIDE 1 V/div 20 VBACKUP 15 10 5 en = 1.6 VP-P 0 10 100 1000 10000 100000 OUTPUT VOLTAGE HIGH (VDD - VOUT) vs. OUTPUT SOURCE CURRENT toc15 OUTPUT SWING HIGH (mV) 4 3 2 1 0 1000 FREQUENCY (Hz) www.maximintegrated.com 100mVP-P INPUT FREQUENCY (Hz) 5 100 -15 10 30 10,000,000 INPUT CURRENT-NOISE DENSITY vs. FREQUENCY 10 -10 35 FREQUENCY (Hz) INPUT CURRENT-NOISE DENSITY (pA/Hz) 10,000,000 40 INPUT VOLTAGE-NOISE DENSITY (nV/Hz) LARGE-SIGNAL RESPONSE (dB) 0 1,000 100,000 INPUT VOLTAGE-NOISE DENSITY vs. FREQUENCY toc12 5 10 -5 FREQUENCY (Hz) LARGE-SIGNAL RESPONSE vs. FREQUENCY -30 0 -20 10 10,000,000 5 10000 toc16 650 600 550 500 450 400 350 300 250 200 150 100 50 0 0 4 8 12 16 20 OUTPUT SOURCE CURRENT (mA) Maxim Integrated 5 MAX44242 20V, Low Input Bias-Current, Low-Noise, Dual Op Amplifier Typical Operating Characteristics (continued) (VDD = 10V, VSS = 0V, outputs have RL = 10k to VDD/2. TA = +25C, unless otherwise specified.) OUTPUT VOLTAGE SWING HIGH vs. TEMPERATURE OUTPUT VOLTAGE LOW (VOUT) vs. OUTPUT SINK CURRENT toc17 600 120 OUTPUT VOLTAGE SWING HIGH (mV) OUTPUT SWING LOW (mV) 450 400 350 300 250 200 150 100 50 100 RL = 2k 80 60 RL = 10k 40 70 OUTPUT VOLTAGE SWING LOW VOL (mV) 550 500 OUTPUT VOLTAGE SWING LOW vs. TEMPERATURE toc18 20 60 0 5 10 15 20 25 40 30 RL = 10k 20 10 0 -50 30 RL = 2k 50 0 0 -20 10 40 70 100 130 -50 -20 TEMPERATURE (C) OUTPUT SINK CURRENT (mA) SMALL-SIGNAL RESPONSE vs. TIME 10 40 70 LARGE-SIGNAL RESPONSE vs. TIME toc20 130 toc21 No LOAD VIN VOUTN VIN 1V/div 50mV/div VINSIDE 100 TEMPERATURE (C) No LOAD VOUTN toc19 VINSIDE VBACKUP VBACKUP VOUT VOUT 1V/div 50mV/div 1s/div 1 s/div 100nF 100 toc22 RESISTIVE LOAD (k) 10 UNSTABLE 1 0.1 STABLE 0.01 STABILITY vs. CAPACITIVE LOAD AND ISOLATION RESISTOR 100 ISOLATION RESISTANCE RISO () STABILITY vs. CAPACITIVE LOAD AND RESISTIVE LOAD toc23 10 UNSTABLE 1 0.1 STABLE 0.01 0.001 100 1000 10000 CAPACITIVE LOAD (pF) www.maximintegrated.com 100000 100 1000 10000 100000 CAPACITIVE LOAD (pF) Maxim Integrated 6 MAX44242 20V, Low Input Bias-Current, Low-Noise, Dual Op Amplifier Typical Operating Characteristics (continued) (VDD = 10V, VSS = 0V, outputs have RL = 10k to VDD/2. TA = +25C, unless otherwise specified.) TOTAL HARMONIC DISTORTION vs. INPUT FREQUENCY vs. AMPLITUDE toc26 TOTAL HARMONIC DISTORTION vs. FREQUENCY toc25 0 2VP-P INPUT -10 RLOAD = 10k -20 -30 -40 -50 -60 -70 -80 RLOAD = 600 RLOAD = 1k -90 RLOAD = 10k -100 -110 TOTAL HARMONIC DISTORTION (dB) TOTAL HARMONIC DISTORTION (dB) 0 -120 10 100 1000 10000 -20 -40 1kHz INPUT FREQUENCY -60 -80 20kHz INPUT FREQUENCY -100 -120 100000 0 FREQUENCY (Hz) CROSSTALK vs. FREQUENCY 0 4 6 8 10 FREQUENCY (Hz) toc27 -40 -60 -80 EMIRR vs. FREQUENCY 100 EMI REJECTION RATIO (dB) -20 CROSSTALK (dB) 2 toc29 80 60 40 20 -100 -120 0 1 10 100 1000 10000 100000 1000000 FREQUENCY (Hz) www.maximintegrated.com 10 100 1000 10000 FREQUENCY (MHz) Maxim Integrated 7 MAX44242 20V, Low Input Bias-Current, Low-Noise, Dual Op Amplifier Pin Configuration TOP VIEW OUTA 1 + MAX44242 8 VDD INA- 2 7 OUTB INA+ 3 6 INB- VSS 4 5 INB+ 8MAX/SOT-23 Pin Description PIN NAME FUNCTION 1 OUTA 2 INA- Channel A Negative Input 3 INA+ Channel A Positive Input 4 VSS Negative Supply Voltage. Connect VSS to ground if single supply is used. 5 INB+ Channel B Positive Input 6 INB- Channel B Negative Input 7 OUTB 8 VDD Channel A Output Channel B Output Positive Supply Voltage Detailed Description Integrated EMI Filter Input Bias Current The MAX44242 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. Combining high input impedance, low input bias current, wide bandwidth, and fast settling time, the MAX44242 is an ideal amplifier for driving precision analog-to-digital inputs and buffering digital-to-analog converter outputs. The MAX44242 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. www.maximintegrated.com Electromagnetic interference (EMI) noise occurs at higher frequency that results in malfunction or degradation of electrical equipment. 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. Maxim Integrated 8 MAX44242 20V, Low Input Bias-Current, Low-Noise, Dual Op Amplifier 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 MAX44242 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 capacitors 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 impedance 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 2, 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 (I ) produced by the R 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 x 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 100k +5V MAX44242 5V D1 R2 30k R3 20k C2 10nF Figure 1. High-Impedance Source/Sensor Preamp Application www.maximintegrated.com Maxim Integrated 9 MAX44242 20V, Low Input Bias-Current, Low-Noise, Dual Op Amplifier Package Information Ordering Information PART TEMP RANGE PINPACKAGE TOP MARK MAX44242AKA+ -40C to +125C 8 SOT23 AETK MAX44242AUA+ -40C to +125C 8 MAX -- +Denotes lead(Pb)-free/RoHS-compliant package. Chip Information 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 TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 8 SOT23 K8+5 21-0078 90-0176 8 MAX U8+1 21-0036 90-0092 PROCESS: BiCMOS www.maximintegrated.com Maxim Integrated 10 MAX44242 20V, Low Input Bias-Current, Low-Noise, Dual Op Amplifier Revision History REVISION NUMBER REVISION DATE 0 12/13 Initial release -- 1 11/15 Updated Pin Configuration diagram 8 2 4/18 Updated Typical Application Circuit 1 DESCRIPTION PAGES CHANGED 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. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. (c) 2018 Maxim Integrated Products, Inc. 11 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Maxim Integrated: MAX44242AUA+T MAX44242AKA+T