19-2424; Rev 3; 8/11 Ultra-Low Offset/Drift, Low-Noise, Precision SOT23 Amplifiers The MAX4238/MAX4239 are low-noise, low-drift, ultrahigh precision amplifiers that offer near-zero DC offset and drift through the use of patented autocorrelating zeroing techniques. This method constantly measures and compensates the input offset, eliminating drift over time and temperature and the effect of 1/f noise. Both devices feature rail-to-rail outputs, operate from a single 2.7V to 5.5V supply, and consume only 600A. An activelow shutdown mode decreases supply current to 0.1A. The MAX4238 is unity-gain stable with a gain-bandwidth product of 1MHz, while the decompensated MAX4239 is stable with AV 10V/V and a GBWP of 6.5MHz. The MAX4238/MAX4239 are available in 8-pin narrow SO, 6-pin TDFN and SOT23 packages. Features o Ultra-Low, 0.1V Offset Voltage 2.0V (max) at +25C 2.5V (max) at -40C to +85C 3.5V (max) at -40C to +125C o Low 10nV/C Drift o Specified over the -40C to +125C Automotive Temperature Range o Low Noise: 1.5VP-P from DC to 10Hz o 150dB AVOL, 140dB PSRR, 140dB CMRR o High Gain-Bandwidth Product 1MHz (MAX4238) 6.5MHz (MAX4239) o 0.1A Shutdown Mode Applications o Rail-to-Rail Output (RL = 1k) Thermocouples o Low 600A Supply Current Strain Gauges o Ground-Sensing Input Electronic Scales o Single 2.7V to 5.5V Supply Voltage Range Medical Instrumentation o Available in a Space-Saving 6-Pin SOT23 and TDFN Packages Instrumentation Amplifiers Ordering Information PART Typical Application Circuit 5V 18k 360 STRAIN GAUGE ADC AV = 100 18k MAX4238/ MAX4239 AIN PIN-PACKAGE TOP MARK MAX4238AUT-T 6 SOT23 AAZZ MAX4238AUT/V+T 6 SOT23 -- MAX4238ASA 8 SO MAX4238ATT+T 6 TDFN-EP* +ANG MAX4239AUT-T 6 SOT23 ABAA -- MAX4239AUT/V+T 6 SOT23 -- MAX4239ASA 8 SO -- MAX4239ATT+T 6 TDFN-EP* +ANH Note: All devices are specified over the -40C to +125C operating temperature range. +Denotes a lead(Pb)-free/RoHS-compliant package. *EP = Exposed paddle. /V denotes an automotive-qualified part. Selector Guide PART MAX4238 MAX4239 MINIMUM STABLE GAIN 1V/V 10V/V GAIN BANDWIDTH (MHz) 1 6.5 Pin Configurations appear at end of data sheet. ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim's website at www.maxim-ic.com. 1 MAX4238/MAX4239 General Description MAX4238/MAX4239 Ultra-Low Offset/Drift, Low-Noise, Precision SOT23 Amplifiers ABSOLUTE MAXIMUM RATINGS Power-Supply Voltage (VCC to GND).......................................6V All Other Pins ................................(VGND - 0.3V) to (VCC + 0.3V) Output Short-Circuit Duration (OUT shorted to VCC or GND) ...............................Continuous Continuous Power Dissipation (TA = +70C) 6-Pin Plastic SOT23 (derate 9.1mW/C above +70C) ...............................727mW 8-Pin Plastic SO (derate 5.88mW/C above +70C) ....471mW 6-Pin TDFN-EP (derate 18.2mW above +70C) .........1454mW Operating Temperature Range .........................-40C to +125C Junction Temperature ......................................................+150C Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) .................................+300C Soldering Temperature (reflow) Lead(Pb)-Free Packages.............................................+260C Packages Containing Lead..........................................+240C Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (2.7V V CC 5.5V, V CM = V GND = 0V, V OUT = V CC /2, R L = 10k connected to V CC /2, SHDN = V CC , T A = +25 C, unless otherwise noted.) PARAMETER Input Offset Voltage SYMBOL CONDITIONS MIN TYP MAX UNITS 0.1 2 V VOS (Note 1) Input Bias Current IB (Note 2) 1 pA Input Offset Current IOS (Note 2) 2 pA RS = 100, 0.01Hz to 10Hz 1.5 VP-P f = 1kHz 30 NV/Hz Long-Term Offset Drift Peak-to-Peak Input Noise Voltage Input Voltage-Noise Density Common-Mode Input Voltage Range 50 enP-P en VCM VCC - 1.3 VGND - 0.1 Inferred from CMRR test nV/1000hr V Common-Mode Rejection Ratio CMRR -0.1V VCM VCC - 1.3V (Note 1) 120 140 dB Power-Supply Rejection Ratio PSRR 2.7V VCC 5.5V (Note 1) 120 140 dB 125 150 Large-Signal Voltage Gain AVOL 0.05V VOUT VCC - 0.05V (Note 1) RL = 10k 0.1V VOUT VCC - 0.1V (Note 1) RL = 1k RL = 10k Output Voltage Swing VOH/VOL RL = 1k dB 125 145 VCC - VOH 4 VOL 4 10 VCC - VOH 35 50 VOL 35 50 Output Short-Circuit Current To either supply Output Leakage Current 0 V OUT VCC, SHDN = GND (Note 2) 0.01 Slew Rate VCC = 5V, CL = 100pF, VOUT = 2V step MAX4238 0.35 MAX4239 1.6 RL = 10k, CL = 100pF, measured at f = 100kHz MAX4238 1 MAX4239 6.5 RL = 10k, CL = 100pF, phase margin = 60 MAX4238 1 MAX4239 10 Gain-Bandwidth Product Minimum Stable Closed-Loop Gain 2 GBWP 10 40 _______________________________________________________________________________________ mV mA 1 A V/s MHz V/V Ultra-Low Offset/Drift, Low-Noise, Precision SOT23 Amplifiers (2.7V V CC 5.5V, V CM = V GND = 0V, V OUT = V CC /2, R L = 10k connected to V CC /2, SHDN = V CC , T A = +25 C, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS RL = 10k, CL = 100pF, phase margin = 60 Maximum Closed-Loop Gain Settling Time -1V step AV = 10 (Note 4) Overload Recovery Time Startup Time AV = 10 MIN 1000 MAX4239 6700 0.1% (10 bit) 0.5 0.025% (12 bit) 1.0 0.006% (14 bit) 1.7 0.0015% (16 bit) 2.3 0.1% (10 bit) 3.3 0.025% (12 bit) 4.1 0.006% (14 bit) 4.9 0.0015% (16 bit) 5.7 0.1% (10 bit) 1.8 0.025% (12 bit) 2.6 0.006% (14 bit) 3.4 0.0015% (16 bit) Supply Voltage Range VCC Supply Current ICC Shutdown Logic-High VIH Shutdown Logic-Low VIL Shutdown Input Current TYP MAX4238 Inferred by PSRR test MAX V/V ms ms ms 4.3 2.7 5.5 SHDN = VCC, no load, VCC = 5.5V 600 850 SHDN = GND, VCC = 5.5V 0.1 1 2.2 0V V SHDN VCC UNITS V A V 0.1 0.8 V 1 A _______________________________________________________________________________________ 3 MAX4238/MAX4239 ELECTRICAL CHARACTERISTICS (continued) MAX4238/MAX4239 Ultra-Low Offset/Drift, Low-Noise, Precision SOT23 Amplifiers ELECTRICAL CHARACTERISTICS (2.7V VCC 5.5V, VCM = GND = 0V, VOUT = VCC/2, RL = 10k connected to VCC/2, SHDN = VCC, TA = -40C to +125C, unless otherwise noted.) (Note 5) PARAMETER Input Offset Voltage Input Offset Drift Common-Mode Input Voltage Range Common-Mode Rejection Ratio Power-Supply Rejection Ratio Large-Signal Voltage Gain SYMBOL CONDITIONS VOS (Note 1) TCVOS (Note 1) VCM CMRR PSRR 10 VGND - 0.05 2.7V VCC 5.5V (Note 1) 120 RL = 10k, 0.1V VOUT VCC - 0.1V (Note 1) 125 VOH/VOL RL = 1k TA = -40C to +85C Supply Voltage Range VCC Supply Current ICC Shutdown Logic High VIH Shutdown Logic Low VIL UNITS V nV/C VCC - 1.4 V dB 90 dB dB TA = -40C to +125C 95 0.1V VOUT VCC - 0.1V, TA = -40C to +85C 120 0.2V VOUT VCC - 0.2V, TA = -40C to +125C 80 dB VCC - VOH 20 20 VOL VCC - VOH 100 VOL 100 0V VOUT VCC, SHDN = GND (Note 3) Output Leakage Current Shutdown Input Current 3.5 115 RL = 10k MAX TA = -40C to +125C VGND - 0.05V TA = -40C to +85C VCM VCC TA = -40C to +125C 1.4V (Note 1) AVOL TYP 2.5 Inferred from CMRR test RL = 1k (Note 1) Output Voltage Swing MIN TA = -40C to +85C Inferred by PSRR test 2.7 SHDN = VCC, no load, VCC = 5.5V 2 A 5.5 V 900 SHDN = GND, VCC = 5.5V 2 2.2 0V V SHDN VCC mV A V 0.7 V 2 A Note 1: Guaranteed by design. Thermocouple and leakage effects preclude measurement of this parameter during production testing. Devices are screened during production testing to eliminate defective units. Note 2: IN+ and IN- are gates to CMOS transistors with typical input bias current of 1pA. CMOS leakage is so small that it is impractical to test and guarantee in production. Devices are screened during production testing to eliminate defective units. Note 3: Leakage does not include leakage through feedback resistors. Note 4: Overload recovery time is the time required for the device to recover from saturation when the output has been driven to either rail. Note 5: Specifications are 100% tested at TA = +25C, unless otherwise noted. Limits over temperature are guaranteed by design. 4 _______________________________________________________________________________________ Ultra-Low Offset/Drift, Low-Noise, Precision SOT23 Amplifiers 30 20 0 TA = -40C 0 0.3 0.6 0.9 1.2 1.5 TA = +25C TA = -40C 0 -0.4 2.7 3.4 4.1 4.8 5.5 0 0.9 1.8 2.7 COMMON-MODE VOLTAGE (V) OUTPUT HIGH VOLTAGE vs. OUTPUT SOURCE CURRENT OUTPUT LOW VOLTAGE vs. OUTPUT SINK CURRENT MAX4238 GAIN AND PHASE vs. FREQUENCY 0.20 VCC = 2.7V 0.15 VCC = 5V 0.10 MAX4238/39 toc05 0.25 0.35 0.30 OUTPUT LOW VOLTAGE (V) MAX4238/39 toc04 VOH = VCC - VOUT 0.05 0.25 VCC = 2.7V 0.20 VCC = 5V 0.15 0.10 0.05 0 0 0 5 10 15 20 0 5 10 15 80 60 40 20 0 -20 -40 -60 -80 -100 -120 -140 -160 -180 VCC = 5V GAIN = 60dB RL = 10k CL = 0pF 100 20 1k 10k 100k 1M MAX4238 GAIN AND PHASE vs. FREQUENCY VCC = 5V GAIN = 60dB RL = 10k CL = 100pF 1k 10k 100k FREQUENCY (Hz) 1M 10M VCC = 5V GAIN = 40dB RL = 10k CL = 0pF 100 1k 10k 100k FREQUENCY (Hz) 1M 10M 80 60 40 20 0 -20 -40 -60 -80 -100 -120 -140 -160 -180 10M MAX4238/39 toc09 MAX4238 GAIN AND PHASE vs. FREQUENCY GAIN AND PHASE (dB/DEGREES) MAX4238 GAIN AND PHASE vs. FREQUENCY MAX4238/39 toc08 FREQUENCY (Hz) GAIN AND PHASE (dB/DEGREES) SINK CURRENT (mA) MAX4238/39 toc07 SOURCE CURRENT (mA) 80 60 40 20 0 -20 -40 -60 -80 -100 -120 -140 -160 -180 3.6 MAX4238/39 toc06 SUPPLY VOLTAGE (V) GAIN AND PHASE (dB/DEGREES) OFFSET VOLTAGE (V) 0.30 100 TA = +125C 0.2 -0.2 -0.4 -1.5 -1.2 -0.9 -0.6 -0.3 0 OUTPUT HIGH VOLTAGE (V) TA = +25C -0.2 10 GAIN AND PHASE (dB/DEGREES) 0.2 OFFSET VOLTAGE (V) TA = +125C OFFSET VOLTAGE (V) 40 0.4 MAX4238/39 toc02 0.4 MAX4238/39 toc01 PERCENTAGE OF UNITS (%) 50 80 60 40 20 0 -20 -40 -60 -80 -100 -120 -140 -160 -180 OFFSET VOLTAGE vs. COMMON-MODE VOLTAGE OFFSET VOLTAGE vs. SUPPLY VOLTAGE MAX4238/39 toc03 INPUT OFFSET DISTRIBUTION VCC = 5V GAIN = 40dB RL = 10k CL = 68pF 100 1k 10k 100k 1M 10M FREQUENCY (Hz) _______________________________________________________________________________________ 5 MAX4238/MAX4239 Typical Operating Characteristics (VCC = 5V, VCM = 0V, RL = 10k connected to VCC/2, SHDN = VCC, TA = +25C, unless otherwise noted.) Typical Operating Characteristics (continued) (VCC = 5V, VCM = 0V, RL = 10k connected to VCC/2, SHDN = VCC, TA = +25C, unless otherwise noted.) MAX4239 GAIN AND PHASE vs. FREQUENCY VCC = 5V GAIN = 40dB RL = 10k CL = 0pF 1E+2 1E+3 1E+4 1E+5 1E+6 1E+3 MAx4238/39 toc12 TA = +125C 500 VCC = 5V GAIN = 40dB RL = 10k CL = 100pF 1E+2 1E+7 SUPPLY CURRENT vs. SUPPLY VOLTAGE 600 SUPPLY CURRENT (A) 80 60 40 20 0 -20 -40 -60 -80 -100 -120 -140 -160 -180 MAX4238/39 toc11 GAIN AND PHASE (dB/DEGREES) TA = -40C 400 TA = +25C 300 200 100 0 1E+4 1E+5 1E+6 0 1E+7 1 2 3 5 FREQUENCY (Hz) SUPPLY VOLTAGE (V) POWER-SUPPLY REJECTION RATIO vs. FREQUENCY COMMON-MODE REJECTION RATIO vs. FREQUENCY MAX4238 LARGE-SIGNAL TRANSIENT RESPONSE -20 -40 -20 -40 CMRR (dB) -60 -80 MAX4238/39 toc15 0 MAX4238/39 toc13 0 IN 1V/div -60 -80 -100 -100 -120 -120 -140 -140 -160 OUT 1V/div -160 0.01 0.1 1 10 100 1000 0.01 0.1 1 10 100 10s/div 1000 FREQUENCY (kHz) FREQUENCY (kHz) MAX4238 SMALL-SIGNAL TRANSIENT RESPONSE MAX4239 SMALL-SIGNAL TRANSIENT RESPONSE MAX4238/39 toc16 MAX4238/39 toc17 AV = 1V/V RL = 2k CL = 100pF OVERVOLTAGE RECOVERY TIME MAX4238/39 toc18 IN 50mV/div IN 50mV/div 0 IN 50mV/div OUT 50mV/div OUT 1V/div OUT 500mV/div 0 400s/div 10s/div 10s/div AV = 1V/V RL = 2k CL = 100pF 6 4 FREQUENCY (Hz) MAX4238/39 toc14 80 60 40 20 0 -20 -40 -60 -80 -100 -120 -140 -160 -180 MAX4238/39 toc10 GAIN AND PHASE (dB/DEGREES) MAX4239 GAIN AND PHASE vs. FREQUENCY PSRR (dB) MAX4238/MAX4239 Ultra-Low Offset/Drift, Low-Noise, Precision SOT23 Amplifiers AV = 10V/V RL = 2k CL = 100pF AV = 100V/V RL = 10k VCC = 2.5V VEE = -2.5V _______________________________________________________________________________________ Ultra-Low Offset/Drift, Low-Noise, Precision SOT23 Amplifiers SHUTDOWN WAVEFORM DC TO 10Hz NOISE MAX4238/39 toc20 MAX4238/39 toc19 SHDN 2V/div 2V/div OUT 1V/div OUT 10s/div 1s/div RL = 10k CL = 100pF VCC = 2.5V VEE = -2.5V Offset Error Sources Pin Description PIN TDFN SOT23 SO NAME FUNCTION 1 1 6 OUT Amplifier Output 2 2 4 GND Ground 3 3 3 IN+ Noninverting Input 4 4 2 IN- Inverting Input Shutdown Input. Active-low shutdown, connect to VCC for normal operation. 5 5 1 SHDN 6 6 7 VCC Positive Power Supply No Connection. Not internally connected. -- -- 5, 8 N.C. -- -- -- EP Exposed Pad (TDFN only). Connect EP to GND. Detailed Description The MAX4238/MAX4239 are high-precision amplifiers that have less than 2.5V of input-referred offset and low 1/f noise. These characteristics are achieved through a patented autozeroing technique that samples and cancels the input offset and noise of the amplifier. The pseudorandom clock frequency varies from 10kHz to 15kHz, reducing intermodulation distortion present in chopper-stabilized amplifiers. To achieve very low offset, several sources of error common to autozero-type amplifiers need to be considered. The first contributor is the settling of the sampling capacitor. This type of error is independent of inputsource impedance, or the size of the external gain-setting resistors. Maxim uses a patented design technique to avoid large changes in the voltage on the sampling capacitor to reduce settling time errors. The second error contributor, which is present in both autozero and chopper-type amplifiers, is the charge injection from the switches. The charge injection appears as current spikes at the input, and combined with the impedance seen at the amplifier's input, contributes to input offset voltage. Minimize this feedthrough by reducing the size of the gain-setting resistors and the input-source impedance. A capacitor in parallel with the feedback resistor reduces the amount of clock feedthrough to the output by limiting the closed-loop bandwidth of the device. The design of the MAX4238/MAX4239 minimizes the effects of settling and charge injection to allow specification of an input offset voltage of 0.1V (typ) and less than 2.5V over temperature (-40C to +85C). 1/f Noise 1/f noise, inherent in all semiconductor devices, is inversely proportional to frequency. 1/f noise increases 3dB/octave and dominates amplifier noise at lower frequencies. This noise appears as a constantly changing voltage in series with any signal being measured. The MAX4238/MAX4239 treat 1/f noise as a slow varying offset error, inherently canceling the 1/f noise. _______________________________________________________________________________________ 7 MAX4238/MAX4239 Typical Operating Characteristics (continued) (VCC = 5V, VCM = 0V, RL = 10k connected to VCC/2, SHDN = VCC, TA = +25C, unless otherwise noted.) Output Overload Recovery Pin Configurations Autozeroing amplifiers typically require a substantial amount of time to recover from an output overload. This is due to the time it takes for the null amplifier to correct the main amplifier to a valid output. The MAX4238/ MAX4239 require only 3.3ms to recover from an output overload (see Electrical Characteristics and Typical Operating Characteristics). VCC SHDN IN- TOP VIEW 6 5 4 EP* Shutdown MAX4238/ MAX4239 The MAX4238/MAX4239 feature a low-power (0.1A) shutdown mode. When SHDN is pulled low, the clock stops and the device output enters a high-impedance state. Connect SHDN to VCC for normal operation. ADC Buffer Amplifier The low offset, fast settling time, and 1/f noise cancellation of the MAX4238/MAX4239 make these devices ideal for ADC buffers. The MAX4238/MAX4239 are well suited for low-speed, high-accuracy applications such as strain gauges (see Typical Application Circuit). Error Budget Example When using the MAX4238/MAX4239 as an ADC buffer, the temperature drift should be taken into account when determining the maximum input signal. With a typical offset drift of 10nV/C, the drift over a 10C range is 100nV. Setting this equal to 1/2LSB in a 16-bit system yields a full-scale range of 13mV. With a single 2.7V supply, an acceptable closed-loop gain is AV = 200. This provides sufficient gain while maintaining headroom. *CONNECT EP TO GND. MAX4238/ MAX4239 MAX4238/ MAX4239 SHDN 1 8 N.C. IN- 2 7 VCC 3 6 OUT GND 4 5 N.C. IN+ OUT 1 6 VCC GND 2 5 SHDN IN+ 3 4 IN- SO SOT23 Chip Information PROCESS: BiCMOS Package Information For the latest package outline information and land patterns (footprints), go to www.maxim-ic.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 8 3 TDFN (3mm x 3mm x 0.8mm) Minimum and Maximum Gain Configurations The MAX4238 is a unity-gain stable amplifier with a gainbandwidth product (GBWP) of 1MHz. The MAX4239 is decompensated for a GBWP of 6.5MHz and is stable with a gain of 10V/V. Unlike conventional operational amplifiers, the MAX4238/MAX4239 have a maximum gain specification. To maintain stability, set the gain of the MAX4238 between AV = 1000V/V to 1V/V, and set the gain of the MAX4239 between AV = 6700V/V and 10V/V. 2 IN+ Applications Information 1 GND + OUT MAX4238/MAX4239 Ultra-Low Offset/Drift, Low-Noise, Precision SOT23 Amplifiers PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 6 SOT23 U6F-6 21-0058 90-0175 8 SO S8-4 21-0041 90-0096 6 TDFN T633+2 21-0137 90-0058 _______________________________________________________________________________________ Ultra-Low Offset/Drift, Low-Noise, Precision SOT23 Amplifiers PAGES CHANGED REVISION NUMBER REVISION DATE 2 5/06 -- -- 3 8/11 Added MAX4238 and MAX4239 automotive-qualified parts 1 DESCRIPTION Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 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. 9 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 (c) 2011 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc. MAX4238/MAX4239 Revision History