19-2110; Rev 0; 8/01 SOT23, Very High Precision, 3V/5V Rail-to-Rail Op Amps The MAX4236/MAX4237 are high-precision op amps that feature an exceptionally low offset voltage and offset voltage temperature coefficient without using any chopper techniques. The MAX4236 and MAX4237 have a typical large-signal, open-loop voltage gain of 120dB. These devices have an ultra-low input-bias current of 1pA. The MAX4236 is unity-gain stable with a gainbandwidth product of 1.7MHz, while the MAX4237 is stable for closed-loop gains greater than 5V/V with a gain-bandwidth product of 7.5MHz. Both devices have a shutdown function in which the quiescent current is reduced to less than 0.1µA, and the amplifier output is forced into a high-impedance state. The input common-mode range of the MAX4236/ MAX4237 extends below the negative supply range, and the output swings Rail-to-Rail®. These features make the amplifiers ideal for applications with +3V or +5V single power supplies. The MAX4236/MAX4237 are specified for the extended temperature range (-40°C to +85°C) and are available in tiny SOT23, µMAX, and SO packages. For greater accuracy, the A grade µMAX and SO packages are tested to guarantee 20µV (max) offset voltage at +25°C and less then 2µV/°C drift. Applications Strain Gauges Features ♦ Ultra-Low Offset Voltage 20µV (max) at +25°C (Grade A) 50µV (max) at +25°C (Grade B, 6-Pin SOT23) ♦ Ultra-Low Offset Voltage Drift 2µV/°C (max) (Grade A) 4.5µV/°C (max) (Grade B, 6-Pin SOT23) 5.5µV/°C (max) (6-Pin SOT23) ♦ Ultra-Low 1pA Input Bias Current ♦ High Open-Loop Voltage Gain: 110dB (min) (RL = 100kΩ) ♦ Compatible with +3V and +5V Single-Supply Power Systems ♦ Ground Sensing: Input Common-Mode Range Includes Negative Rail ♦ Rail-to-Rail Output Swing into a 1kΩ Load ♦ 350µA Quiescent Current ♦ Gain-Bandwidth Product 1.7MHz (MAX4236, AV = 1V/V) 7.5MHz (MAX4237, AV = 5V/V) ♦ 200pF Capacitive Load Handling Capability ♦ Shutdown Mode: 0.1µA Quiescent Current, Places Output in a High-Impedance State Piezoelectric Sensors Thermocouple Amplifiers ♦ Available in Space-Saving SOT23 and µMAX Packages Electrochemical Sensors Battery-Powered Instrumentation Instrumentation Amplifiers Ordering Information Rail-to-Rail is a registered trademark of Nippon Motorola, Inc. Pin Configurations TOP VIEW OUT 1 VEE 2 6 MAX4236 MAX4237 5 VCC SHDN 4 IN- TEMP. RANGE PIN-PACKAGE MAX4236EUT-T -40°C to +85°C 6 SOT23-6 MAX4236AEUA -40°C to +85°C 8 µMAX MAX4236BEUA -40°C to +85°C 8 µMAX N.C. 1 8 SHDN MAX4236AESA -40°C to +85°C 8 SO IN- 2 7 VCC MAX4236BESA -40°C to +85°C 8 SO IN+ 3 6 OUT MAX4237EUT-T -40°C to +85°C 6 SOT23-6 VEE 4 5 N.C. MAX4237AEUA -40°C to +85°C 8 µMAX MAX4237BEUA -40°C to +85°C 8 µMAX MAX4237AESA -40°C to +85°C 8 SO MAX4237BESA -40°C to +85°C 8 SO MAX4236A/B MAX4237A/B SO-8/µMAX IN+ 3 PART SOT23-6 ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. 1 MAX4236/MAX4237 General Description MAX4236/MAX4237 SOT23, Very High Precision, 3V/5V Rail-To-Rail Op Amps ABSOLUTE MAXIMUM RATINGS Supply Voltage (VCC - VEE) ......................................-0.3V to +6V Analog Input Voltage (IN+ or IN-) ....(VEE - 0.3V) to (VCC + 0.3V) Logic Input Voltage (SHDN) ............(VEE - 0.3V) to (VCC + 0.3V) Current into Any Pin ............................................................20mA Output Short-Circuit Duration....Continuous to Either VCC or VEE Continuous Power Dissipation (TA = +70°C) 6-Pin SOT23-6 (derate 8.7mW/°C above +70°C) .........696mW 8-Pin µMAX (derate 4.5mW/°C above +70°C) ..............362mW 8-Pin SO (derate 5.9mW/°C above +70°C)...................471mW Operating Temperature Range ...........................-40°C to +85°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. ELECTRICAL CHARACTERISTICS (SO-8 and µMAX-8) (VCC = +2.4V to +5.5V, VEE = 0, VCM = 0, VOUT = VCC/2, RL = 100kΩ to VCC/2, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) (Note 1) PARAMETER Supply Voltage Range SYMBOL VCC CONDITIONS MIN Guaranteed by the PSRR test 2.4 VCC = +5V Quiescent Supply Current ICC VCC = +3V VCC = +5V, Grade A Input Offset Voltage Input Offset Voltage Temperature Coefficient Input Bias Current VOS TCVOS VCC = +5V, Grade B VCC = +5V (Note 3) TYP MAX UNITS 5.5 V In normal mode 350 In shutdown mode 0.1 440 2 In normal mode 350 440 In shutdown mode 0.1 2 TA = +25oC ±5 ±20 TA = TMIN to TMAX ±150 o TA = +25 C ±5 TA = TMIN to TMAX ±50 µA µV ±340 Grade A ±0.6 ±2 Grade B ±0.6 ±4.5 ±500 µV/°C IB (Note 2) ±1 Input Offset Current IOS (Note 2) ±1 pA Input Resistance RIN Differential or common mode 1000 MΩ Input Common-Mode Voltage VCM Guaranteed by the CMRR test Common-Mode Rejection Ratio CMRR VCC = +5V; -0.15V ≤ VCM ≤ (VCC - 1.2V) VCC = +3.0V; -0.15V ≤ VCM ≤ (VCC - 1.2V) Power-Supply Rejection Ratio 2 PSRR VCC = +2.4V to +5.5V -0.15 TA = +25oC 84 TA = TMIN to TMAX 80 TA = +25oC 82 TA = TMIN to TMAX 78 o TA = +25 C 97 TA = TMIN to TMAX 95 VCC - 1.2 pA V 102 dB 102 120 _______________________________________________________________________________________ dB SOT23, Very High Precision, 3V/5V Rail-To-Rail Op Amps (VCC = +2.4V to +5.5V, VEE = 0, VCM = 0, VOUT = VCC/2, RL = 100kΩ to VCC/2, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS VCC = +5V, RL connected to VCC/2, TA = +25oC VCC = +5V, RL connected to VCC/2, TA = TMIN to TMAX Large-Signal Voltage Gain MIN TYP RL = 100kΩ, VOUT = 15mV to (VCC - 50mV) 110 128 RL = 1kΩ, VOUT = 0.15V to (VCC - 0.3V) 105 114 RL = 100kΩ, VOUT = 15mV to (VCC - 50mV) 110 RL = 1kΩ, VOUT = 0.15V to (VCC - 0.3V) 100 VCC = +3V, RL connected to VCC/2, TA = TMIN to TMAX RL = 100kΩ, VOUT = 15mV to (VCC - 50mV) 110 128 RL = 1kΩ, VOUT = 0.15V to (VCC - 0.3V) 100 114 RL = 100kΩ, VOUT = 15mV to (VCC - 50mV) 105 RL = 1kΩ, VOUT = 0.15V to (VCC - 0.3V) 95 VCC = +5V, RL connected to VCC /2, RL = 100kΩ Gain-Bandwidth Product 2 10 VOL - VEE 3 10 VCC - VOH 150 250 VOL - VEE 50 100 mV IOUT(SC) GBWP Shorted to VEE 10 Shorted to VCC 30 RL = ∞, CL = 5pF Slew Rate SR VCC = +5V, VOUT = 4V step Settling Time tS VOUT settling to within 0.01% Total Harmonic Distortion VCC - VOH VOUT VCC = +5V, RL connected to VCC/2, RL = 1kΩ Output Short-Circuit Current THD UNITS dB AVOL VCC = +3V, RL connected to VCC/2, TA = +25oC Output Voltage Swing MAX MAX4236 1.7 MAX4237 7.5 MAX4236 0.3 MAX4237 1.3 MAX4236 1 MAX4237 1 f = 5kHz, VOUT = 2Vp-p, VCC = +5V RL = 10kΩ 0.001 mA MHz V/µs µs % _______________________________________________________________________________________ 3 MAX4236/MAX4237 ELECTRICAL CHARACTERISTICS (SO-8 and µMAX-8) (continued) MAX4236/MAX4237 SOT23, Very High Precision, 3V/5V Rail-To-Rail Op Amps ELECTRICAL CHARACTERISTICS (SO-8 and µMAX-8) (continued) (VCC = +2.4V to +5.5V, VEE = 0, VCM = 0, VOUT = VCC/2, RL = 100kΩ to VCC/2, 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 Input Capacitance CIN f = 100kHz 7.5 Input Voltage Noise Density en f = 1kHz 14 nV/√Hz f = 0.1Hz to 10Hz 0.2 µVp-p Input Noise Voltage enp-p Capacitive Load Stability CLOAD Shutdown Mode Output Leakage IOUT(SH) SHDN Logic Low VIL SHDN Logic High VIH SHDN Input Current No sustained oscillations MAX4236 200 MAX4237 200 Device in shutdown mode (SHDN = VEE) VOUT = 0 to VCC ±0.01 pF pF ±1.0 µA 0.3 ✕ VCC V 0.7 ✕ VCC V SHDN = VEE or VCC 1 3 µA Shutdown Delay Time t(SH) RL = 1kΩ 1 µs Shutdown Recovery Time t(EN) RL = 1kΩ 4 µs ELECTRICAL CHARACTERISTICS (SOT23-6) (VCC = +2.4V to +5.5V, VEE = 0, VCM = 0, VOUT = VCC/2, RL = 100kΩ to VCC/2, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) (Note 1) PARAMETER Supply Voltage Range SYMBOL VCC CONDITIONS Guaranteed by the PSRR test VCC = +5V Quiescent Supply Current ICC VCC = +3V Input Offset Voltage Input Offset Voltage Temperature Coefficient (Note 2) Input Bias Current VOS VCC = +5V TCVOS VCC = +5V MIN TYP 2.4 440 0.1 2 In normal mode 350 440 In shutdown mode 0.1 2 TA = +25°C ±5 ±50 TA = TMIN to TMAX ±600 ±0.6 ±5.5 ±500 ±1 (Note 2) ±1 Input Resistance RIN Differential or common mode Input Common-Mode Voltage VCM Guaranteed by the CMRR test VCC = +5V, -0.15V ≤ VCM ≤ (VCC - 1.2V) VCC = +3.0V; -0.15V ≤ VCM ≤ (VCC - 1.2V) 4 V 350 (Note 2) CMRR 5.5 In shutdown mode IB Common-Mode Rejection Ratio UNITS In normal mode IOS Input Offset Current MAX TA = +25°C 82 TA = TMIN to TMAX 80 TA = +25°C 82 TA = TMIN to TMAX 78 µV µV/°C pA pA 1000 -0.15 µA MΩ VCC - 1.2 V 102 102 _______________________________________________________________________________________ dB SOT23, Very High Precision, 3V/5V Rail-To-Rail Op Amps (VCC = +2.4V to +5.5V, VEE = 0, VCM = 0, VOUT = VCC/2, RL = 100kΩ to VCC/2, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) (Note 1) PARAMETER Power-Supply Rejection Ratio SYMBOL PSRR CONDITIONS VCC = +2.4V to +5.5V VCC = +5V, RL connected to VCC/2, TA = +25°C VCC = +5V, RL connected to VCC/2, TA = TMIN to TMAX Large-Signal Voltage Gain AVOL VCC = +3V, RL connected to VCC/2, TA = +25°C VCC = +3V, RL connected to VCC/2, TA = TMIN to TMAX MIN TYP TA = +25°C 97 120 TA = TMIN to TMAX 95 RL = 100kΩ, VOUT = 15mV to (VCC - 50mV) 110 128 RL = 1kΩ, VOUT = 0.15V to (VCC - 0.3V) 100 114 RL = 100kΩ, VOUT = 15mV to (VCC - 50mV) 110 RL = 1kΩ, VOUT = 0.15V to (VCC - 0.3V) 95 RL = 100kΩ, VOUT = 15mV to (VCC - 50mV) 110 128 RL = 1kΩ, VOUT = 0.15V to (VCC - 0.3V) 100 114 RL = 100kΩ, VOUT = 15mV to (VCC - 50mV) 105 RL = 1kΩ, VOUT = 0.15V to (VCC - 0.3V) 95 VCC = +5V, RL connected to VCC/2, RL = 100kΩ Output Voltage Swing Gain-Bandwidth Product Slew Rate dB VCC - VOH 2 10 VOL - VEE 3 10 VCC - VOH 150 250 VOL - VEE 50 100 mV Shorted to VEE 10 Shorted to VCC 30 mA IOUT(SC) GBWP SR UNITS dB VOUT VCC = +5V, RL connected to VCC/2, RL = 1kΩ Output Short-Circuit Current MAX RL = ∞, CL = 15pF VCC = +5V, VOUT = 4V step MAX4236 1.7 MAX4237 7.5 MAX4236 0.3 MAX4237 1.3 MHz V/µs _______________________________________________________________________________________ 5 MAX4236/MAX4237 ELECTRICAL CHARACTERISTICS (SOT23-6) (continued) ELECTRICAL CHARACTERISTICS (SOT23-6) (continued) (VCC = +2.4V to +5.5V, VEE = 0, VCM = 0, VOUT = VCC/2, RL = 100kΩ to VCC/2, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) (Note 1) PARAMETER SYMBOL Settling Time CONDITIONS tS VOUT settling to within 0.01% MIN MAX4236 1 1 THD f = 5kHz, VOUT = 2Vp-p, VCC = +5V RL = 10kΩ Input Capacitance CIN f = 100kHz en Input Voltage Noise Density Input Noise Voltage enp-p Capacitive Load Stability CLOAD Shutdown Mode Output Leakage VIL SHDN Logic High VIH MAX UNITS µs 0.001 % 7.5 pF f = 1kHz 14 nV/√Hz f = 0.1Hz to 10Hz 0.2 µVp-p MAX4236 200 MAX4237 200 No sustained oscillations pF Device in shutdown mode (SHDN = VEE) VOUT = 0 to VCC IOUT(SH) SHDN Logic Low TYP MAX4237 Total Harmonic Distortion ±0.01 ±1.0 µA 0.3 x VCC V 0.7 x VCC SHDN Input Current V SHDN = VEE or VCC 1 Shutdown Delay Time t(SH) RL = 1kΩ 1 µs Shutdown Recovery Time t(EN) RL = 1kΩ 4 µs 3 µA Note 1: All devices are 100% production tested at TA = +25°C; all specifications over temperature are guaranteed by design, unless otherwise specified. Note 2: Guaranteed by design, not production tested. Note 3: Maxim specification limits for the temperature coefficient of the offset voltage (TCVOS) are 100% tested for the A-grade, 8pin SO and µMAX packages. Typical Operating Characteristics (VCC = +5V, VEE = 0, VCM = VCC/2, RL = 100kΩ to VCC/2, TA = +25°C, unless otherwise noted.) TCVOS DISTRIBUTION 20 PERCENT OF UNITS (%) 14 12 10 8 6 4 VCC = 5V 15 10 5 40 20 0 -20 -40 -60 2 -80 0 0 -10 -8 -6 -4 -2 0 2 VOS (µV) 6 60 OFFSET VOLTAGE (µV) VCC = 5V OFFSET VOLTAGE vs. TEMPERATURE 80 MAX4236 toc02 MAX 4236 toc01 16 25 MAX4236 toc02 VOS DISTRIBUTION 18 PERCENT OF UNITS (%) MAX4236/MAX4237 SOT23, Very High Precision, 3V/5V Rail-To-Rail Op Amps 4 6 8 10 -2.0 -1.5 -1.0 -0.5 0 0.5 TCVOS (µV/°C) 1.0 1.5 2.0 -50 -25 0 25 75 50 TEMPERATURE (°C) _______________________________________________________________________________________ 100 125 SOT23, Very High Precision, 3V/5V Rail-To-Rail Op Amps MAX4236/MAX4237 Typical Operating Characteristics (continued) (VCC = +5V, VEE = 0, VCM = VCC/2, RL = 100kΩ to VCC/2, TA = +25°C, unless otherwise noted.) COMMON-MODE REJECTION RATIO vs. COMMON-MODE INPUT VOLTAGE 60 40 20 0 80 60 40 20 1.0 1.5 2.0 2.5 3.0 1 2 3 4 40 20 0.01 5 COMMON-MODE INPUT VOLTAGE (V) COMMON-MODE REJECTION RATIO vs. FREQUENCY (VCC = 3V) POWER-SUPPLY REJECTION RATIO vs. FREQUENCY (VCC = 5V) MAX4236 toc08 100 GAIN (dB) PSSR (dB) 60 0.1 1 10 100 1000 10,000 0.1 1 10 FREQUENCY (kHz) 60 40 VCC = 5V/3V CL = 15pF/200pF 100 1000 -20 0.001 0.01 0.1 80 20 40 40 VCC = 5V/3V CL = 15pF/200pF 20 10 0 100 1000 10,000 100,000 VOUT = 2Vp-p 0.1 THD + NOISE (%) 60 INPUT VOLTAGE NOISE (nV√Hz) 60 PHASE (DEGREES) PHASE 100 1 MAX4236 toc11 25 1 TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY INPUT VOLTAGE NOISE vs. FREQUENCY 100 20 FREQUENCY (kHz) 140 GAIN 10,000 FREQUENCY (kHz) MAX4236 OPEN-LOOP GAIN/PHASE vs. FREQUENCY MAX4236 toc10 120 60 0 0 0.01 20 GAIN 80 40 20 0 80 80 20 20 100 100 40 40 1000 10,000 PHASE 120 80 60 1 10 100 FREQUENCY (kHz) 140 100 80 0.1 MAX4237 OPEN-LOOP GAIN/PHASE vs. FREQUENCY MAX4236 toc09 120 MAX4236 toc07 120 MAX4236 toc06 60 0 0 COMMON-MODE INPUT VOLTAGE (V) 140 GAIN (dB) 80 0 0.5 0 COMMON-MODE REJECTION RATIO (dB) 100 100 15 10 0.01 0.001 5 0 -20 0.001 0.01 0.1 1 10 0 100 1000 10,000 FREQUENCY (kHz) 0.0001 0 0.01 0.1 1 FREQUENCY (kHz) 10 100 10 100 1k 10k 100k FREQUENCY (Hz) _______________________________________________________________________________________ 7 PHASE (DEGREES) 80 120 120 MAX4236 toc12 100 VCC = 5V COMMON-MODE REJECTION RATIO (dB) 120 140 MAX4236 toc05 VCC = 3V COMMON-MODE REJECTION RATIO (dB) MAX4236 toc04 COMMON-MODE REJECTION RATIO (dB) 140 COMMON-MODE REJECTION RATIO vs. FREQUENCY (VCC = 5V) COMMON-MODE REJECTION RATIO vs. COMMON-MODE INPUT VOLTAGE Typical Operating Characteristics (continued) (VCC = +5V, VEE = 0, VCM = VCC/2, RL = 100kΩ to VCC/2, TA = +25°C, unless otherwise noted.) 360 +V = 5V 340 330 TA = -40°C VCC = 5V, RL to VEE TA = +25°C 335 VCC = 5V, RL to VCC 120 TA = +85°C 330 TA = +125°C 100 VCC = 3V, RL to VEE 325 VCC = 3V, RL to VCC 80 +V = 3V 320 RL = 1kΩ 140 GAIN (dB) 370 350 340 SUPPLY CURRENT (µA) SUPPLY CURRENT (µA) 380 MAX4236 toc14 MAX4236 toc13 390 LARGE-SIGNAL GAIN vs. TEMPERATURE SUPPLY CURRENT vs. SUPPLY VOLTAGE 345 MAX4236 toc15 SUPPLY CURRENT vs. TEMPERATURE 400 320 310 0 25 50 75 100 125 5.0 -50 5.5 -25 0 25 50 75 MAXIMUM OUTPUT VOLTAGE vs. TEMPERATURE OUTPUT VOLTAGE vs. SUPPLY VOLTAGE 15 10 VCC = 5V/3V, RL = 100kΩ 5 0 VCC = 5V, RL = 1kΩ 160 140 120 VCC = 3V, RL = 1kΩ 100 80 60 0 25 50 75 100 160 140 100 80 60 20 20 VCC = 5V/3V, RL = 100kΩ -50 -25 0 25 50 75 100 VCC - VOH, RL to VCC 120 40 125 VOL - VEE, RL to VEE 0 3.0 125 3.5 4.0 4.5 5.0 SUPPLY VOLTAGE (V) OUTPUT VOLTAGE vs. SUPPLY VOLTAGE OUTPUT SOURCE CURRENT vs. OUTPUT VOLTAGE OUTPUT SOURCE CURRENT vs. OUTPUT VOLTAGE VOL - VEE 3.0 2.5 2.0 VCC - VOH 1.0 0.5 VCC = 5V 10 8 6 4 2 10 VCC = 3V 9 OUTPUT SOURCE CURRENT (mA) 3.5 12 OUTPUT SOURCE CURRENT (mA) RL = 100kΩ MAX4236 toc20 TEMPERATURE (°C) MAX4236 toc19 TEMPERATURE (°C) 4.0 125 RL = 1kΩ 180 40 0 -25 MAX4236 toc17 180 100 200 OUTPUT VOLTAGE (mV) 20 200 MAXIMUM OUTPUT VOLTAGE (mV) VCC = 3V, RL = 1kΩ 25 1.5 4.5 MINIMUM OUTPUT VOLTAGE vs. TEMPERATURE 30 -50 4.0 TEMPERATURE (°C) MAX4236 toc16 MINIMUM OUTPUT VOLTAGE (mV) 3.5 SUPPLY VOLTAGE (V) VCC = 5V, RL = 1kΩ 35 3.0 TEMPERATURE (°C) 45 40 2.5 MAX4236 toc18 -25 50 8 7 6 5 4 3 2 1 0 0 0 3.0 3.5 4.0 4.5 SUPPLY VOLTAGE (V) 8 60 315 -50 MAX4236 toc21 300 OUTPUT VOLTAGE (mV) MAX4236/MAX4237 SOT23, Very High Precision, 3V/5V Rail-To-Rail Op Amps 5.0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 OUTPUT VOLTAGE (V) 0 0.5 1.0 1.5 2.0 OUTPUT VOLTAGE (V) _______________________________________________________________________________________ 2.5 3.0 SOT23, Very High Precision, 3V/5V Rail-To-Rail Op Amps OUTPUT SINK CURRENT vs. OUTPUT VOLTAGE 60 50 40 30 20 50 40 30 20 10 20 MAX4236 toc24 VCC = 3V OUTPUT TO GND SHORT-CIRCUIT CURRENT (mA) 15 VCC = 5V 10 VCC = 3V 5 SHORTED TO VEE (SOURCING CURRENT) 10 0 0 1.0 1.5 2.0 2.5 3.0 -25 0 25 50 75 TEMPERATURE (°C) SHORT-CIRCUIT CURRENT vs. TEMPERATURE DC I/O TRANSFER CURVE (RLOAD = 100kΩ) DC I/O TRANSFER CURVE (RLOAD = 1kΩ) 2.5 MAX4236 toc25 20 15 10 SHORTED TO VCC (SINKING CURRENT) 1.5 1.0 0.5 0 -0.5 -1.0 -25 0 25 75 50 TEMPERATURE (°C) 100 125 2.0 125 VSUPPLY = ±2.5V 1.0 0.5 0 -0.5 -1.0 -1.5 -2.0 -2.0 -2.5 -100 -50 0 50 100 -100 DIFFERENTIAL INPUT VOLTAGE (µV) -50 0 50 100 DIFFERENTIAL INPUT VOLTAGE (µV) MAX4237 NONINVERTING SMALL-SIGNAL RESPONSE MAX4236 NONINVERTING SMALL-SIGNAL RESPONSE MAX4236 toc28 MAX4236 toc29 0 INPUT 10mV/div 0 0 OUTPUT 10mV/div 0 INPUT 10mV/div OUTPUT 50mV/div 1µs/div 1µs/div VCC = ±2.5V RL = 1kΩ, CL = 15pF AV = 1V/V 100 1.5 -1.5 -2.5 0 2.5 OUTPUT VOLTAGE (V) VCC = 5V 25 VSUPPLY = ±2.5V 2.0 OUTPUT VOLTAGE (V) VCC = 3V 30 -50 -50 OUTPUT VOLTAGE (V) 35 SHORT-CIRCUIT CURRENT (mA) 0.5 OUTPUT VOLTAGE (V) 40 5 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 MAX4236 toc26 0 MAX4236 toc27 OUTPUT SINK CURRENT (mA) 70 60 SHORT-CIRCUIT CURRENT vs. TEMPERATURE MAX4236 toc23 VCC = 5V OUTPUT TO GND OUTPUT SINK CURRENT (mA) 80 MAX4236 toc22 OUTPUT SINK CURRENT vs. OUTPUT VOLTAGE VCC = ±2.5V RL = 1kΩ, CL = 15pF AV = 5V/V _______________________________________________________________________________________ 9 MAX4236/MAX4237 Typical Operating Characteristics (continued) (VCC = +5V, VEE = 0, VCM = VCC/2, RL = 100kΩ to VCC/2, TA = +25°C, unless otherwise noted.) MAX4236/MAX4237 SOT23, Very High Precision, 3V/5V Rail-To-Rail Op Amps Typical Operating Characteristics (continued) (VCC = +5V, VEE = 0, VCM = VCC/2, RL = 100kΩ to VCC/2, TA = +25°C, unless otherwise noted.) MAX4237 NONINVERTING LARGE-SIGNAL RESPONSE MAX4237 NONINVERTING LARGE-SIGNAL RESPONSE MAX4236 toc30 MAX4236 toc31 INPUT 200mV/div 0 0 OUTPUT 1V/div INPUT 200mV/div 0 0 2µs/div OUTPUT 1V/div 1µs/div VCC = ±2.5V RL = 100kΩ, CL = 15pF AV = 5V/V VCC = ±2.5V RL = 1kΩ, CL = 15pF AV = 5V/V MAX4236 NONINVERTING LARGE-SIGNAL RESPONSE MAX4236 NONINVERTING LARGE-SIGNAL RESPONSE MAX4236 toc32 MAX4236 toc33 INPUT 1V/div INPUT 1V/div 0 0 OUTPUT 1V/div 0 0 4µs/div VCC = ±2.5V RL = 1kΩ, CL = 15pF AV = 1V/V 10 OUTPUT 1V/div 4µs/div VCC = ±2.5V RL = 100kΩ, CL = 15pF AV = 1V/V ______________________________________________________________________________________ SOT23, Very High Precision, 3V/5V Rail-To-Rail Op Amps NAME PIN SOT23 SO/µMAX 1 6 FUNCTION OUT Amplifier Output Negative Power Supply. Bypass with a 0.1µF capacitor to ground. Connect to GND for single-supply operation. 2 4 VEE 3 3 IN+ Noninverting Amplifier Input 4 2 IN- Inverting Amplifier Input 5 8 SHDN Shutdown Input. Do not leave floating. Connect to VCC for normal operation or GND to enter the shutdown mode. 6 7 VCC Positive Supply Input. Bypass with a 0.1µF capacitor to ground. — 1, 5 N.C. No Connection. Not internally connected. Detailed Description The MAX4236/MAX4237 are high-precision op amps with a CMOS input stage and an excellent set of DC and AC features. The combination of tight maximum voltage offset, low offset tempco and very low input current make them ideal for use in high-precision DC circuits. They feature low-voltage operation, low-power consumption, high-current drive with rail-to-rail output swing and high-gain bandwidth product. High Accuracy The MAX4236/MAX4237 maximum input offset voltage is 20µV (5µV, typ) for grade A version and 50µV for grade B version at +25°C. The maximum temperature coefficient of the offset voltage for grade A and B are guaranteed to be 2µV/°C and 4.5µV/°C respectively. The parts have an input bias current of 1pA. Noise characteristics are 14nV/√Hz, and a low frequency noise (0.1Hz to 10Hz) of 0.2µVp-p. The CMRR is 102dB, and the PSRR is 120dB. The combination is what is necessary for the design of circuits to process signals while keeping high signal-to-noise ratios, as in stages preceding high-resolution converters, or when they are produced by sensors or transducers generating very small outputs. Rail-to-Rail Outputs, Ground-Sensing Input The input common-mode range extends from (VEE 0.15V) to (VCC - 1.2V) with excellent common-mode rejection. Beyond this range, the amplifier output is a nonlinear function of the input, but does not undergo phase reversal or latch-up (see Typical Operating Characteristics). The output swings to within 150mV of the power-supply rails with a 1kΩ load. The input ground sensing and the rail-to-rail output substantially increase the dynamic range. Power-Up and Shutdown Mode The MAX4236/MAX4237 have a shutdown option. When the shutdown pin (SHDN) is pulled low, the supply current drops to 0.1µA, and the amplifiers are disabled with the output in a high-impedance state. Pulling SHDN high enables the amplifiers. The turn-on time for the amplifiers to come out of shutdown is 4µs. Applications Information As described above, the characteristics of the MAX4236/MAX4237 are excellent for high-precision/ accuracy circuitry, and the high impedance, low-current, low-offset, and noise specifications are very attractive for piezoelectric transducers applications. In these applications, the sensors generate an amount of electric charge proportional to the changes in the mechanical stress applied to them. These charges are transformed into a voltage proportional to the applied force by injecting them into a capacitance and then amplifying the resulting voltage. The voltage is an inverse function of the capacitance into which the charges generated by the transducer/ sensor are injected. This capacitance and the resistance that discharges it, define the low-frequency response of the circuit. It is desirable, once the preferred low-frequency response is known, to maintain the capacitance as low as possible, because the amount of necessary upstream amplification (and the signal-to-noise ratio deterioration) is directly proportional to the capacitance value. The MAX4236/MAX4237 high-impedance, low- ______________________________________________________________________________________ 11 MAX4236/MAX4237 Pin Description MAX4236/MAX4237 SOT23, Very High Precision, 3V/5V Rail-To-Rail Op Amps Selector Guide current, low-noise inputs allow a minimum of capacitance to be used. Piezoresistive transducers applications require many of the same qualities. For those applications the MAX4236/MAX4237 high CMRR, PSRR, and offset stability are also a good match. A typical application for a piezoresistive transducer instrumentation amplifier design using the MAX4236/MAX4237 is shown in the Typical Application Circuit. In general, the MAX4236/MAX4237 are good components for any application in which an amplifier with an almost zero input current is required, including highprecision, long time-constant integrators and electrochemical sensors. Power Supplies The MAX4236/MAX4237 can operate from a single +2.4V to +5.5V power supply, or from ±1.2V to ±2.75V power supplies. The power supply pin(s) must be bypassed to ground with a 0.1µF capacitor as close to the pin as possible. GRADE MINIMUM STABLE GAIN TOP MARK MAX4236EUT — 1 AAUV MAX4236AEUA A 1 — MAX4236BEUA B 1 — MAX4236AESA A 1 — PART MAX4236BESA B 1 — MAX4237EUT — 5 AAUW MAX4237AEUA A 5 — MAX4237BEUA B 5 — MAX4237AESA A 5 — MAX4237BESA B 5 — Typical Application Circuit Layout and Physical Design A good layout improves performance by decreasing the amount of parasitic and stray capacitance, inductance and resistance at the amplifier’s inputs, outputs, and power-supply connections. Since parasitics might be unavoidable, minimize trace lengths, resistor leads, and place external components as close to the pins as possible. In high impedance, low input current applications, input lines guarding and shielding, special grounding, and other physical design and layout techniques, are mandatory if good results are expected. The negative effects of crosstalk, EMI and other forms of interference and noise (thermal, acoustic, etc.) must be accounted for and prevented beforehand for good performance in the type of sensitive circuitry in which the MAX4236/MAX4237 are likely to be used. +VS VOUT MAX4236 -VS +VS LOAD CELL MAX4236 -VS Chip Information TRANSISTOR COUNTS: 224 PROCESS: BiCMOS 12 ______________________________________________________________________________________ SOT23, Very High Precision, 3V/5V Rail-To-Rail Op Amps 6LSOT.EPS 8LUMAXD.EPS ______________________________________________________________________________________ 13 MAX4236/MAX4237 Package Information SOT23, Very High Precision, 3V/5V Rail-To-Rail Op Amps SOICN.EPS MAX4236/MAX4237 Package Information (continued) 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. 14 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.