19-1407; Rev 3; 8/99 SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps Applications Portable Instruments Instruments, Terminals, and Bar-Code Readers Keyless Entry Photodiode Preamps Smart-Card Readers Infrared Receivers for Remote Controls Low-Side Current-Sense Amplifiers Features ♦ GainAmp Family Provides Internal Precision Gain-Setting Resistors in SOT23 (MAX4174/5) ♦ 0.1% Gain Accuracy (RF/RG) (MAX4174/5, MAX4274/5) ♦ 54 Standard Gains Available (MAX4174/5, MAX4274/5) ♦ Open-Loop Unity-Gain-Stable Op Amps (MAX4281/2/4) ♦ Rail-to-Rail Outputs Drive 1kΩ Load ♦ Internal VCC / 2 Biasing (MAX4175/MAX4275) ♦ +2.5V to +5.5V Single Supply ♦ 300µA Supply Current ♦ Up to 23MHz GBW Product ♦ Fault-Protected Inputs Withstand ±17V ♦ Stable with Capacitive Loads Up to 470pF with No Isolation Resistor Ordering Information TEMP. RANGE PINPACKAGE TOP MARK MAX4174_EUK-T -40°C to +85°C MAX4175_EUK-T -40°C to +85°C 5 SOT23-5 5 SOT23-5 †† PART* †† Ordering Information continued at end of data sheet. * Insert the desired gain code (from the Gain Selection Guide) in the blank to complete the part number. †† Refer to the Gain Selection Guide for a list of preferred gains and SOT Top Marks. Selector Guide appears at end of data sheet. Pin Configurations Typical Operating Circuit TOP VIEW +5V MAX4174 VCC OUT 1 0.1µF VCC 5 VCC MAX4175 RB RF + IN+ VEE 2 0.1µF RG RB 4 IN+ 3 IN- SOT23-5 Pin Configurations continued at end of data sheet. INPUT 0.1µF OUT VEE IN- RF RG VEE †Patent pending GainAmp is a trademark of Maxim Integrated Products. Rail-to-Rail is a registered trademark of Nippon Motorola, Ltd. ________________________________________________________________ Maxim Integrated Products 1 For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 1-800-835-8769. MAX4174/5, MAX4274/5, MAX4281/2/4† General Description The MAX4174/MAX4175/MAX4274/MAX4275 GainAmp™ family combines a low-cost Rail-to-Rail® op amp with precision internal gain-setting resistors and VCC / 2 biasing. Factory-trimmed on-chip resistors decrease design size, cost, and layout, and provide 0.1% gain accuracy. Fixed inverting gains from -0.25V/V to -100V/V or noninverting gains from +1.25V/V to +101V/V are available. These devices operate from a single +2.5V to +5.5V supply and consume only 300µA. GainAmp amplifiers are optimally compensated for each gain version, achieving exceptional GBW products up to 23MHz (AV = +25V/V to +101V/V). High-voltage fault protection withstands ±17V at either input without excessive current draw. Three versions are available in this amplifier family: single/ dual/quad open-loop, unity-gain stable (MAX4281/ MAX4282/MAX4284); single/dual fixed gain (MAX4174/ MAX4274); and single/dual fixed gain plus internal V CC / 2 bias at the noninverting input (MAX4175/ MAX4275), which simplifies input biasing in single-supply designs. The input common-mode voltage range of the open-loop amplifiers extends from 150mV below the negative supply to within 1.2V of the positive supply. The outputs can swing rail-to-rail and drive a 1kΩ load while maintaining excellent DC accuracy. The amplifier is stable for capacitive loads up to 470pF. MAX4174/5, MAX4274/5, MAX4281/2/4 SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps ABSOLUTE MAXIMUM RATINGS Supply Voltage (VCC to VEE) ....................................-0.3V to +6V Voltage Inputs (IN_) MAX4281/4282/4284.....................(VEE - 0.3V) to (VCC + 0.3V) MAX4174/4175/4274/4275 (with respect to GND) ...........±17V Output Short-Circuit Duration (OUT_).....................................Continuous to Either VEE or VCC Continuous Power Dissipation (TA = +70°C) 5-Pin SOT23 (derate 7.1mW/°C above +70°C).............571mW 8-Pin SO (derate 5.88mW/°C above +70°C).................471mW 8-Pin µMAX (derate 4.1mW/°C above +70°C) ............330mW 14-Pin SO (derate 8.3mW/°C above +70°C)...............667mW 16-Pin QSOP (derate 8.3mW/°C above +70°C)..........667mW Operating Temperature Range ...........................-40°C to +85°C Maximum Junction Temperature .....................................+150°C Storage Temperature Range .............................-65°C to +150°C Lead Temperature (soldering, 10sec) .............................+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—MAX4174/MAX4175/MAX4274/MAX4275 Fixed-Gain Amplifiers (VCC = +2.5V to +5.5V, VEE = 0, VIN+ = VIN- = VCC / 2, RL to VCC / 2, RL = open, 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 TYP MAX UNITS 5.5 V VCC = 3V 300 460 VCC = 5V 330 510 VCC = 3V 320 480 Guaranteed by PSRR tests MAX4174/MAX4274 2.5 Supply Current (per Amplifier) ICC 355 530 Input Offset Voltage VOS RL = 100kΩ ±0.5 ±2.5 IBIAS IN_+, MAX4174/MAX4274 (Note 2) ±0.05 MAX4175/MAX4275, includes VCC / 2 bias resistors VCC = 5V Input Offset Voltage Drift Input Bias Current ±5 Inverting Input Resistance AV < 25V/V 150 AV > 25V/V 40 µA mV µV/°C ±10 nA kΩ Noninverting Input Resistance MAX4174/MAX4274 1000 MΩ MAX4175/MAX4275 75 kΩ IN_+ Bias Voltage MAX4175/MAX4275, VIN+ = VIN- IN_+ Input Voltage Range Guaranteed by functional test (Note 3) IN_- Input Voltage Range Power-Supply Rejection Ratio PSRR Closed-Loop Output Impedance ROUT Short-Circuit Current Output Voltage Swing (Note 4) VCC / 2 + 0.25 V VEE VCC - 1.2 V Guaranteed by functional test VEE VCC V VCC = 2.5V to 5.5V 70 90 dB 0.02 Ω Shorted to VEE 10 Shorted to VCC 65 RL = 100kΩ VOH/VOL RL = 1kΩ 2 VCC / 2 - 0.25 VCC - VOH 2 mA 8 VOL - VEE 2 8 VCC - VOH 150 250 VOL - VEE 60 150 _______________________________________________________________________________________ mV SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps (VCC = +2.5V to +5.5V, VEE = 0, VIN+ = VIN- = VCC / 2, RL to VCC / 2, RL = open, TA = TMIN to TMAX, unless otherwise noted. Typical PARAMETER SYMBOL Power-Up Time CONDITIONS MIN Output settling to 1% Slew Rate SR Settling Time to Within 0.01% TYP MAX UNITS 1 ms VCC = 5V, VOUT = 4V step 0.7 V/µs VCC = 5V, VOUT = 4V step 7 µs Input Noise Voltage Density en f = 10kHz (Note 5) 90 nV/√Hz Input Noise Current Density in f = 10kHz 4 fA/√Hz No sustained oscillations 470 pF (VEE + 25mV) < VOUT < (VCC - 25mV), RL = 100kΩ (Note 6) 0.1 Capacitive Load Stability CLOAD DC Gain Accuracy -3dB Bandwidth BW-3dB Gain = +1.25V/V 1700 Gain = +3V/V 970 Gain = +5V/V 970 Gain = +10V/V 640 Gain = +25V/V 590 Gain = +51V/V 330 0.5 % kHz ELECTRICAL CHARACTERISTICS—MAX4281/MAX4282/MAX4284 Open-Loop Op Amps (VCC = +2.5V to +5.5V, VEE = 0, VIN+ = VIN- = VCC / 2, RL to VCC / 2, RL = open, 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 Supply Current (per Amplifier) ICC Input Offset Voltage VOS CONDITIONS Guaranteed by PSRR tests MIN MAX V 290 450 µA VCC = 5V 320 500 µA RL = 100kΩ ±0.5 ±2 ±5 IBIAS Input Offset Current IOS Input Resistance RIN Input Capacitance CIN UNITS 5.5 VCC = 3V Input Offset Voltage Drift Input Bias Current TYP 2.5 Differential or common mode mV µV/°C ±0.05 ±10 ±10 ±1000 nA pA 1000 MΩ 2.5 pF Common-Mode Input Voltage Range CMVR Guaranteed by CMRR test Common-Mode Rejection Ratio CMRR VEE - 0.15V ≤ VCM ≤ VCC - 1.2V 60 90 dB Power-Supply Rejection Ratio PSRR VCC = 2.5V to 5.5V 70 90 dB Closed-Loop Output Impedance ROUT AV = 1V/V 0.02 Ω VEE - 0.15 VCC - 1.2 V _______________________________________________________________________________________ 3 MAX4174/5, MAX4274/5, MAX4281/2/4 ELECTRICAL CHARACTERISTICS—MAX4174/MAX4175/MAX4274/MAX4275 Fixed-Gain Amplifiers (continued) ELECTRICAL CHARACTERISTICS—MAX4281/MAX4282/MAX4284 Open-Loop Op Amps (continued) (VCC = +2.5V to +5.5V, VEE = 0, VIN+ = VIN- = VCC / 2, RL to VCC / 2, RL = open, TA = TMIN to TMAX, unless otherwise noted. Typical values are at VCC = +5V and TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS Large-Signal Voltage Gain AVOL VOH/VOL RL = 1kΩ Gain Bandwidth Product 90 80 10 65 120 100 Input Noise Current Density UNITS mA mA dB dB 8 VOL - VEE 2 8 VCC - VOH 160 250 VOL - VEE 60 100 mV 2 MHz 0.7 V/µs SR VCC = 5V, VOUT = 4V step VCC = 5V, VOUT = 4V step 7 µs en f = 10kHz 60 nV/√Hz in f = 10kHz 1.8 fA/√Hz No sustained oscillations, AV = 1V/V 470 pF 1 ms Settling Time to within 0.01% Input Noise Voltage Density MAX 2 GBW Slew Rate Capacitive Load Stability TYP VCC - VOH RL = 100kΩ Output Voltage Swing MIN Shorted to VEE Shorted to VCC VEE + 0.05V < VOUT < VCC - 0.1V, RL = 100kΩ VEE + 0.25V < VOUT < VCC - 0.3V, RL = 1kΩ Short-Circuit Current CLOAD Power-Up Time Output settling to 1% Note 1: MAX4174/MAX4175/MAX4281 and MAX4274/MAX4275/MAX4282 and MAX4284 are 100% production tested at TA = +25°C. All temperature limits are guaranteed by design. Note 2: Guaranteed by design. Note 3: The input common-mode range for IN_+ is guaranteed by a functional test. A similar test is done on the IN_- input. See the Applications Information section for more information on the input voltage range of the GainAmp. Note 4: For AV = -0.5V/V and AV = -0.25V/V, the output voltage swing is limited by the input voltage range. Note 5: Includes noise from on-chip resistors. Note 6: The gain accuracy test is performed with the GainAmp in noninverting configuration. The output voltage swing is limited by the input voltage range for certain gains and supply voltage conditions. For situations where the output voltage swing is limited by the valid input range, the output limits are adjusted accordingly. Typical Operating Characteristics (VCC = +5V, RL = 100kΩ to VCC / 2, small-signal VOUT = 100mVp-p, large-signal VOUT = 1Vp-p, TA = +25°C, unless otherwise noted.) 2 -2 -3 AV = +2.25V/V -5 -6 AV = +2.5V/V 1 0 -1 AV = +4V/V -2 -3 10k 100k FREQUENCY (Hz) 1M 10M 2 AV = +5V/V 1 0 -1 -2 AV = +9V/V -3 -4 -4 -5 -5 -6 -6 1k 3 NORMALIZED GAIN (dB) 0 -1 -4 3 NORMALIZED GAIN (dB) AV = +1.25V/V 1 4 MAX4174 TOC02 2 4 4 MAX4174 TOC01 4 3 LARGE-SIGNAL GAIN vs. FREQUENCY LARGE-SIGNAL GAIN vs. FREQUENCY MAX4174 TOC03 LARGE-SIGNAL GAIN vs. FREQUENCY NORMALIZED GAIN (dB) MAX4174/5, MAX4274/5, MAX4281/2/4 SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps 1k 10k 100k FREQUENCY (Hz) 1M 10M 1k 10k 100k FREQUENCY (Hz) _______________________________________________________________________________________ 1M 10M SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps MAX4174/MAX4175 1 0 -1 AV = +50V/V -2 -3 0 -1 -2 -4 -4 -5 -5 -6 -6 100k 1M 10M -6 1k 10k 100k 1M 1k 10M 100k 1M FREQUENCY (Hz) FREQUENCY (Hz) SMALL-SIGNAL GAIN vs. FREQUENCY SMALL-SIGNAL GAIN vs. FREQUENCY SMALL-SIGNAL GAIN vs. FREQUENCY 0 -1 -2 -3 AV = +2.25V/V -4 1 0 -1 AV = +4V/V -2 3 2 NORMALIZED GAIN (dB) 1 AV = +2.5V/V -3 0 -1 -3 -4 -4 -5 -6 -6 -6 1M 10M 1k 10k FREQUENCY (Hz) 3 2 -2 -3 AV = +21V/V AV = +25V/V 1 0 -1 -2 -3 AV = +50V/V -4 -5 -6 1M 10M 3 2 0 -2 AV = +100V/V -3 -4 -6 100k AV = +51V/V -1 -5 FREQUENCY (Hz) 10M 1 -6 10k 1M 4 -5 1k 100k SMALL-SIGNAL GAIN vs. FREQUENCY NORMALIZED GAIN (dB) 0 -1 FREQUENCY (Hz) 10k FREQUENCY (Hz) 4 NORMALIZED GAIN (dB) AV = +10V/V 1 100k 1k 10M MAX4174 TOC11 3 10k 1M SMALL-SIGNAL GAIN vs. FREQUENCY MAX4174 TOC10 4 -4 100k FREQUENCY (Hz) SMALL-SIGNAL GAIN vs. FREQUENCY 2 AV = +9V/V -2 -5 100k AV = +5V/V 1 -5 10k 10M MAX4174 TOC09 3 2 4 MAX4174 TOC08 AV = +1.25V/V 4 MAX4174 TOC07 2 1k 10k FREQUENCY (Hz) 3 1k AV = +100V/V -3 -5 10k AV = +51V/V 1 -4 4 NORMALIZED GAIN (dB) 2 MAX4174 TOC12 AV = +21V/V -3 AV = +25V/V 3 NORMALIZED GAIN (dB) 0 -1 1k NORMALIZED GAIN (dB) 2 NORMALIZED GAIN (dB) 1 -2 3 NORMALIZED GAIN (dB) NORMALIZED GAIN (dB) AV = +10V/V 4 MAX4174 TOC05 3 2 4 MAX4174 TOC04 4 LARGE-SIGNAL GAIN vs. FREQUENCY LARGE-SIGNAL GAIN vs. FREQUENCY MAX4174 TOC06 LARGE-SIGNAL GAIN vs. FREQUENCY 1M 10M 1k 10k 100k 1M 10M FREQUENCY (Hz) _______________________________________________________________________________________ 5 MAX4174/5, MAX4274/5, MAX4281/2/4 Typical Operating Characteristics (continued) (VCC = +5V, RL = 100kΩ to VCC / 2, small-signal VOUT = 100mVp-p, large-signal VOUT = 1Vp-p, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VCC = +5V, RL = 100kΩ to VCC / 2, small-signal VOUT = 100mVp-p, large-signal VOUT = 1Vp-p, TA = +25°C, unless otherwise noted.) MAX4174/MAX4175 TOTAL HARMONIC DISTORTION vs. FREQUENCY TOTAL HARMONIC DISTORTION vs. FREQUENCY VOUT = 1Vp-p -20 VOUT = 1Vp-p -20 -40 -60 THD (dB) -40 THD (dB) MAX4174 TOC14 0 MAX4174 TOC13 0 AV = +10V/V AV = +1.25V/V -80 -60 AV = +51V/V -80 AV = +25V/V -100 -100 AV = +3V/V -120 -120 1k 10k 100k 1k 1M 10k 100k 1M FREQUENCY (Hz) FREQUENCY (Hz) TOTAL HARMONIC DISTORTION vs. OUTPUT VOLTAGE SWING -60 MAX4174 TOC15 f = 10kHz -70 MAX4174 TOC16 TOTAL HARMONIC DISTORTION vs. OUTPUT VOLTAGE SWING -60 f = 10kHz -70 AV = +51V/V AV = +10V/V -80 THD (dB) THD (dB) -80 -90 AV = +1.25V/V -100 -90 AV = +25V/V -100 AV = +3V/V -110 -110 -120 -120 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 VOLTAGE SWING (Vp-p) VOLTAGE SWING (Vp-p) VOLTAGE NOISE DENSITY vs. FREQUENCY (AV = +25, +51) AV = +3V/V 100 AV = +1.25V/V MAX4174/5 toc 18 MAX4174/5 toc 17 AV = +10V/V 1000 VOLTAGE NOISE DENSITY (nV/√Hz) 1000 AV = +25V/V 100 AV = +51V/V CURRENT NOISE DENSITY vs. FREQUENCY 10 CURRENT NOISE DENSITY (fA/√Hz) VOLTAGE NOISE DENSITY vs. FREQUENCY (AV = +1.25, +3, +10) MAX4174/5 toc19 0 VOLTAGE NOISE DENSITY (nV/√Hz) MAX4174/5, MAX4274/5, MAX4281/2/4 SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps INCLUDES RESISTOR NOISE 10 10 1 10 100 1k FREQUENCY (Hz) 6 10k 100k 1 1 10 100 1k FREQUENCY (Hz) 10k 100k 1 10 100 1k FREQUENCY (Hz) _______________________________________________________________________________________ 10k 100k SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps MAX4174/MAX4175 LARGE-SIGNAL PULSE RESPONSE INPUT VOLTAGE MAX4174/5 toc 21 MAX4174/5 toc 20 SMALL-SIGNAL PULSE RESPONSE INPUT VOLTAGE AV = +1.25V/V OUTPUT 50mV/div AV = +1.25V/V OUTPUT 500mV/div AV = +3V/V OUTPUT 50mV/div AV = +3V/V OUTPUT 50mV/div AV = +5V/V OUTPUT 50mV/div AV = +5V/V OUTPUT 500mV/div AV = +10V/V OUTPUT 50mV/div AV = +10V/V OUTPUT 500mV/div AV = +25V/V OUTPUT 50mV/div AV = +25V/V OUTPUT 500mV/div AV = +51V/V OUTPUT 50mV/div AV = +51V/V OUTPUT 500mV/div 2µs/div CL = 0 2µs/div CL = 0 _______________________________________________________________________________________ 7 MAX4174/5, MAX4274/5, MAX4281/2/4 Typical Operating Characteristics (continued) (VCC = +5V, RL = 100kΩ to VCC / 2, small-signal VOUT = 100mVp-p, large-signal VOUT = 1Vp-p, TA = +25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VCC = +5V, RL = 100kΩ to VCC / 2, small-signal VOUT = 100mVp-p, large-signal VOUT = 1Vp-p, TA = +25°C, unless otherwise noted.) MAX4174/MAX4175/MAX4281/MAX4282/MAX4284 POWER-SUPPLY REJECTION vs. FREQUENCY OUTPUT IMPEDANCE (Ω) -85 MAX4174 TOC24 4.9 4.8 10 4.7 VSWING (Vp-p) -80 5.0 MAX4174 TOC23 100 MAX4174 TOC22 -75 PSR (dB) OUTPUT VOLTAGE SWING vs. RLOAD OUTPUT IMPEDANCE vs. FREQUENCY -70 1 4.6 4.5 4.4 4.3 -90 0.1 -95 0.01 4.2 4.1 1k 10k 100k 1M 4.0 100 1k FREQUENCY (Hz) 10k 100k 1 1M 800 50 VCC = 2.5V -50 VCC = 5.5V MAX4174/5 toc 26 100 INPUT BIAS CURRENT (pA) 150 INPUT OFFSET VOLTAGE (µV) 1000 MAX4174/5 toc 25 200 0 -100 600 VCC = 5.5V 400 200 VCC = 2.5V 0 -150 -200 -200 -50 -35 -20 -5 10 25 40 55 70 85 -45 -30 -15 TEMPERATURE (°C) VOH AND VOL vs. TEMPERATURE (VCC = 2.5V) VCC = 4V 80 VOLTAGE (mV) 300 VOH, RL = 10kΩ 0 -20 -60 VCC = 2.5V VOH, RL = 100kΩ 20 -40 VCC = 3V VOH, RL = 1kΩ 60 40 320 260 VOL, RL = 100kΩ VOL, RL = 10kΩ VOL, RL = 1kΩ -80 240 -100 -50 -35 -20 -5 10 25 40 TEMPERATURE (°C) 8 100 VOLTAGE (mV) VCC = 5V 340 55 70 85 15 30 45 60 75 90 VOH AND VOL vs. TEMPERATURE (VCC = 5.5V) MAX4174/5 toc 28 VCC = 5.5V MAX4174/5 toc 27 380 0 TEMPERATURE (°C) SUPPLY CURRENT vs. TEMPERATURE 280 100 INPUT BIAS CURRENT vs. TEMPERATURE INPUT OFFSET VOLTAGE vs. TEMPERATURE 360 10 RLOAD (kΩ) FREQUENCY (Hz) -50 -35 -20 -5 10 25 40 TEMPERATURE (°C) 55 70 85 200 180 160 140 120 100 80 60 40 20 0 -20 -40 -60 -80 -100 MAX4174/5 toc 29 100 SUPPLY CURRENT (µA) MAX4174/5, MAX4274/5, MAX4281/2/4 SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps VOH, RL = 1kΩ VOH, RL = 100kΩ VOH, RL = 10kΩ VOL, RL = 100kΩ VOL, RL = 100kΩ VOL, RL = 1kΩ -50 -35 -20 -5 10 25 40 TEMPERATURE (°C) _______________________________________________________________________________________ 55 70 85 SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps MAX4281/MAX4282/MAX4284 10 100 1k 10k 100k 1M 2 3 2 1 1 0 GAIN (dB) GAIN (dB) MAX4174/5 toc32 4 MAX4174/5 toc31 3 PHASE (degrees) 0 -45 -90 -135 -180 -225 -270 -315 10M LARGE-SIGNAL GAIN vs. FREQUENCY -1 -2 0 -1 -2 -3 -3 -4 -4 -5 -5 -6 -6 1k 10k 100k 1M 10M 1k 10k 100k 1M FREQUENCY (Hz) FREQUENCY (Hz) FREQUENCY (Hz) COMMON-MODE REJECTION vs. FREQUENCY VOLTAGE NOISE DENSITY vs. FREQUENCY CURRENT NOISE DENSITY vs. FREQUENCY -30 -40 -50 -60 -70 -80 100 10 10M MAX4174/5 toc35 -20 1000 CURRENT NOISE DENSITY (fA/√Hz) MAX4174/5 toc33 0 -10 MAX4174/5 toc34 1 CMR (dB) 4 MAX4174/5 toc30 160 140 120 100 80 60 40 20 0 -20 -40 SMALL-SIGNAL GAIN vs. FREQUENCY VOLTAGE NOISE DENSITY (nV/√Hz) OPEN-LOOP GAIN (dB) OPEN-LOOP GAIN AND PHASE vs. FREQUENCY -90 10 -100 1k 10k 100k 1 1 10M 10 100 1k 10k 100k 1 10 100 1k 10k FREQUENCY (Hz) FREQUENCY (Hz) TOTAL HARMONIC DISTORTION vs. FREQUENCY MAX4282 CROSSTALK vs. FREQUENCY MAX4284 CROSSTALK vs. FREQUENCY MAX4174/5 toc36 -50 -55 -60 -70 -80 -90 -65 -70 -75 -80 -85 -100 -110 -120 THREE AMPLIFIERS DRIVEN, ONE OUTPUT MEASURED -55 CROSSTALK (dB) -60 CROSSTALK (dB) -40 -50 -50 100k MAX4174/5 toc38 FREQUENCY (Hz) 0 AV = 1 -10 VOUT = 1Vp-p -20 -30 THD (dB) 1M MAX4174/5 toc37 100 -60 -65 -70 -90 -95 1k 10k 100k FREQUENCY (Hz) 1M -75 1k 10k 100k FREQUENCY (Hz) 1M 10M 1k 10k 100k 1M 10M FREQUENCY (Hz) _______________________________________________________________________________________ 9 MAX4174/5, MAX4274/5, MAX4281/2/4 Typical Operating Characteristics (VCC = +5V, RL = 100kΩ to VCC / 2, small-signal VOUT = 100mVp-p, large-signal VOUT = 1Vp-p, TA = +25°C, unless otherwise noted.) MAX4174/5, MAX4274/5, MAX4281/2/4 SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps Pin Description PIN MAX4281 5 SOT23 8 SO MAX4174/ MAX4175 MAX4282 MAX4274/ MAX4275 5 SOT23 8 SO/µMAX 8 SO/µMAX 14 SO/TSSOP 1 6 1 1, 7 1, 7 1, 7, 8, 14 2 4 2 4 4 11 3 3 3 3, 5 NAME FUNCTION 16 QSOP NAME FUNCTION 1, 7, 10, 16 OUT, OUTA, OUTB, OUTC, OUTD 13 VEE Negative Supply or Ground Noninverting Amplifier Input. Internally biased to VCC / 2 for MAX4175/MAX4275 MAX4284 3, 5 3, 5, 10, 12 3, 5, 12, 14 IN+, INA+, INB+, INC+, IND+ 2, 6, 11, 15 IN-, INA-, INB-, INC-, IND- Amplifier Output Inverting Amplifier Input. Connects to RG for MAX4174/ 4175/4274/4275. 4 2 4 2, 6 2, 6 2, 6, 9, 13 5 7 5 8 8 4 4 VCC Positive Supply — 1, 5, 8 — — — — 8, 9 N.C. No Connection. Not internally connected. Functional Diagrams VCC VCC VCC VCC MAX4174 IN+ MAX4281 IN+ OUT OUT IN- RG RB 150k RB 150k MAX4175 IN+ RF OUT VEE RG IN- RF IN- VEE VEE VEE 10 ______________________________________________________________________________________ SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps Maxim’s GainAmp fixed-gain amplifiers combine a lowcost rail-to-rail op amp with internal gain-setting resistors. Factory-trimmed on-chip resistors provide 0.1% gain accuracy while decreasing design size, cost, and layout. Three versions are available in this amplifier family: single/dual/quad open-loop, unity-gain-stable devices (MAX4281/MAX4282/MAX4284); single/dual fixed-gain devices (MAX4174/MAX4274); and single/ dual devices with fixed gain plus internal VCC / 2 bias at the noninverting input (MAX4175/MAX4275). All amplifiers feature rail-to-rail outputs and drive a 1kΩ load while maintaining excellent DC accuracy. Open-Loop Op Amps The single/dual/quad MAX4281/MAX4282/MAX4284 are high-performance, open-loop op amps with rail-torail outputs. These devices are compensated for unitygain stability, and feature a gain bandwidth (GBW) of 2MHz. The op amps in these ICs feature an input common-mode range that extends from 150mV below the negative rail to within 1.2V of the positive rail. These high performance op amps serve as the core for this family of GainAmp fixed-gain amplifiers. Although the -3dB bandwidth will not correspond to that of a fixedgain amplifier in higher gain configurations, these open-loop op-amps can be used to prototype designs. ly increases usable bandwidth, while decompensation above gains of +25V/V offers diminished returns. VCC / 2 Internal Bias The MAX4175/MAX4275 GainAmp fixed-gain amplifiers with the VCC / 2 bias option are identical to standard GainAmp fixed-gain amplifiers, with the added feature of VCC / 2 internal bias at the noninverting inputs. Two 150kΩ resistors form a voltage-divider for self-biasing the noninverting input, eliminating external bias resistors for AC-coupled applications, and allowing maximum signal swing at the op amp’s rail-to-rail output for single-supply systems (see Typical Operating Circuit). For DC-coupled applications, use the MAX4174/ MAX4274. High-Voltage (±17V) Input Fault Protection The MAX4174/MAX4175/MAX4274/MAX4275 include ±17V input fault protection. For normal operation, see the input voltage range specification in the Electrical Characteristics. Overdriven inputs up to ±17V will not VCC AV = R AV = 1 + F RG RF RG -RF RG IN- Internal Gain-Setting Resistors Maxim’s proprietary laser trimming techniques produce the necessary RF/RG values (Figure 1), so many gain offerings are easily available. These GainAmp fixed-gain amplifiers feature a negative-feedback resistor network that is laser trimmed to provide a gain-setting feedback ratio (RF/RG) with 0.1% typical accuracy. The standard op amp pinouts allow the GainAmp fixed-gain amplifiers to drop in directly to existing board designs, easily replacing op-amp-plus-resistor gain blocks. VEE OUT IN+ Figure 1. Internal Gain-Setting Resistors 60 GainAmp Bandwidth 50 GAIN (dB) GainAmp fixed-gain amplifiers feature factory-trimmed precision resistors to provide fixed inverting gains from -0.25V/V to -100V/V or noninverting gains from +1.25V/V to +101V/V. The op-amp core is decompensated strategically over the gain-set options to maximize bandwidth. Open-loop decompensation increases GBW product, ensuring that usable bandwidth is maintained with increasing closed-loop gains. A GainAmp with a fixed gain of AV = 100V/V has a -3dB bandwidth of 230kHz. By comparison, a unity-gain-stable op amp configured for AV = 100V/V would yield a -3dB bandwidth of only 20kHz (Figure 2). Decompensation is performed at five intermediate gain sets, as shown in the Gain Selection Guide. Low gain decompensation great- MAX4281, AV = 100 2MHz GBW MAX4174, AV = 100 23MHz GBW 40 -3dB 20kHz 30 230kHz 20 10 0 10 100 1k 10k 100k 1M 10M FREQUENCY (Hz) Figure 2. Gain-Bandwidth Comparison ______________________________________________________________________________________ 11 MAX4174/5, MAX4274/5, MAX4281/2/4 Detailed Description MAX4174/5, MAX4274/5, MAX4281/2/4 SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps cause output phase reversal. A back-to-back SCR structure at the input pins allows either input to safely swing ±17V relative to VEE (Figure 3). Additionally, the internal op-amp inputs are diode clamped to either supply rail for the protection of sensitive input stage circuitry. Current through the clamp diodes is limited by a 5kΩ resistor at the noninverting input, and by RG at the inverting input. An IN+ or IN- fault voltage as high as ±17V will cause less than 3.5mA of current to flow through the input pin, protecting both the GainAmp and the signal source from damage. Applications Information GainAmp fixed-gain amplifiers offer a precision, fixed gain amplifier in a small package that can be used in a variety of circuit board designs. GainAmp fixed-gain amplifiers can be used in many op amp circuits that use resistive negative feedback to set gain, and that do not require other connections to the op-amp inverting input. Both inverting and noninverting op-amp configurations can be implemented easily using a GainAmp. GainAmp Input Voltage Range The MAX4174/MAX4175/MAX4274/MAX4275 combine both an op amp and gain-setting feedback resistors on the same chip. Because the inverting input pin is actually tied to the RG input series resistor, the inverting input voltage range is different from the noninverting input voltage range. Just as with a discrete design, care must be taken not to saturate the inputs/output of the core op amp, to avoid signal distortions or clipping. The inverting inputs (IN_-) of the MAX4174/MAX4175/ MAX4274/MAX4275 must be within the supply rails or signal distortion may result. The GainAmp’s inverting input structure includes diodes to both supplies, such that driving the inverting input beyond the rails may cause signal distortions (Figure 1). For applications that require sensing voltages beyond the rails, use the MAX4281/MAX4282/MAX4284 open-loop op amps (Figure 4). RF RG IN17V SCR VCC VCC VEE MAX4174 MAX4175 MAX4274 MAX4275 5k IN+ 17V SCR VEE VEE VEE NOTE: INPUT STAGE PROTECTION INCLUDES TWO 17V SCRs AND TWO DIODES AT THE INPUT STAGE. BIAS RESISTORS (MAX4175/MAX4275 ONLY) Figure 3. Input Protection 12 ______________________________________________________________________________________ OUT SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps VCC MAX4175 RB VCC 0.1µF VOUT = RB VCC - VIN 2 ( RRFG ) VIN RG RF VOUT = -RF (VIN) RG VIN RG Figure 4. Single-Supply, DC-Coupled Inverting Amplifier with Negative Input Voltage RF Figure 6. Single-Supply, AC-Coupled Inverting Amplifier MAX4174 VCC VCC MAX4174 VIN VOUT = - VIN R VOUT = VIN 1+ F RG ( ( RRFG ) ) VEE VEE RF VIN RG RF Figure 5. Dual-Supply, DC-Coupled Inverting Amplifier GainAmp Signal Coupling and Configurations Common op-amp configurations include both noninverting and inverting amplifiers. Figures 5–8 show various single and dual-supply circuit configurations. Single-supply systems benefit from a midsupply bias on the noninverting input (provided internally on MAX4175/MAX4275), as this produces a quiescent DC level at the center of the rail-to-rail output stage signal swing. For dual-supply systems, ground-referenced signals may be DC-coupled into the inverting or noninverting inputs. RG Figure 7. Dual-Supply, AC-Coupled Noninverting Amplifier IN_+ Filter on MAX4175/MAX4275 Internal resistor biasing of the VCC / 2 bias options couples power-supply noise directly to the op amp’s noninverting input. To minimize high-frequency power-supply noise coupling, add a 1µF to 0.1µF capacitor from IN+ to ground to create a lowpass filter (Figure 6). The lowpass filter resulting from the internal bias resistors and added capacitor can help eliminate higher frequency power-supply noise coupling through the noninverting input. ______________________________________________________________________________________ 13 MAX4174/5, MAX4274/5, MAX4281/2/4 MAX4281 VCC MAX4174/5, MAX4274/5, MAX4281/2/4 SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps Supply Bypassing and Board Layout All devices in the GainAmp family operate from a +2.5V to +5.5V single supply or from ±1.25V to ±2.75V dual supplies. For single-supply operation, bypass the power supply with a 0.1µF capacitor to ground. For dual supplies, bypass each supply to ground. Bypass with capacitors as close to the device as possible, to minimize lead inductance and noise. A printed circuit board with a low-inductance ground plane is recommended. Capacitive-Load Stability Driving large capacitive loads can cause instability in most low-power, rail-to-rail output amplifiers. The fixed- gain amplifiers of this GainAmp family are stable with capacitive loads up to 470pF. Stability with higher capacitive loads can be improved by adding an isolation resistor in series with the op-amp output, as shown in Figure 9. This resistor improves the circuit’s phase margin by isolating the load capacitor from the amplifier’s output. In Figure 10, a 1000pF capacitor is driven with a 100Ω isolation resistor exhibiting some overshoot but no oscillation. Figures 11 and 12 show the typical small-signal pulse responses of GainAmp fixed-gain amplifiers with 250pF and 470pF capacitive loads and no isolation resistor. MAX4174 INPUT VCC VIN R VOUT = VIN 1+ F RG ( ) AV = +5V/V 50mV/div OUTPUT AV = +5V/V 500mV/div OUTPUT VEE RF RG Figure 8. Dual-Supply, DC-Coupled Noninverting Amplifier Figure 10. Small-Signal/Large-Signal Transient Response with Excessive Capacitive Load with Isolation Resistor MAX4174 RG RF VCC RISO INPUT OUTPUT CL RL VEE Figure 9. Dual-Supply, Capacitive-Load Driving Circuit 14 ______________________________________________________________________________________ SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps INPUT AV = +1.25V/V OUTPUT 50mV/div AV = +1.25V/V OUTPUT 50mV/div AV = +3V/V OUTPUT 50mV/div AV = +3V/V OUTPUT 50mV/div AV = +5V/V OUTPUT 50mV/div AV = +5V/V OUTPUT 50mV/div AV = +10V/V OUTPUT 50mV/div AV = +10V/V OUTPUT 50mV/div MAX4174/5, MAX4274/5, MAX4281/2/4 INPUT AV = +25V/V OUTPUT 50mV/div AV = +25V/V OUTPUT 50mV/div AV = +51V/V OUTPUT 50mV/div AV = +51V/V OUTPUT 50mV/div 2µs/div Figure 11. MAX4174/MAX4175 Small-Signal Pulse Response (CL = 250pF, RL = 100kΩ) 2µs/div Figure 12. MAX4174/MAX4175 Small-Signal Pulse Response (CL = 470pF, RL = 100kΩ) ______________________________________________________________________________________ 15 SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps MAX4174/5, MAX4274/5, MAX4281/2/4 Gain Selection Guide GAIN CODE RF/RG INVERTING GAIN 1+ (RF/RG) NONINVERTING GAIN -3dB BW (kHz)† MAX4174 AB* 0.25 1.25 1700 ACDS ACET AC 0.5 1.5 1280 ACDT ACEU TOP MARK MAX4175 AD* 1 2 590 ACDU ACEV AE 1.25 2.25 450 ACDV ACEW AF 1.5 2.5 1180 ACDW ACEX ACEY AG* 2 3 970 ACDX AH 2.5 3.5 820 ACDY ACEZ AJ 3 4 690 ACDZ ACFA AK* 4 5 970 ACEA ACFB AL 5 6 790 ACEB ACFC AM 6 7 640 ACEC ACFD AN 8 9 480 ACED ACFE AO* 9 10 640 ACEE ACFF BA* 10 11 560 ACEF ACFG ACFH BB 12.5 13.5 460 ACEG BC 15 16 390 ACEH ACFI BD 20 21 300 ACEI ACFJ BE* 24 25 590 ACEJ ACFK BF 25 26 580 ACEK ACFL BG 30 31 510 ACEL ACFM BH 40 41 390 ACEM ACFN BJ* 49 50 310 ACEN ACFO BK* 50 51 330 ACEO ACFP BL 60 61 310 ACEP ACFQ BM 80 81 260 ACEQ ACFR BN* 99 100 230 ACER ACFS CA* 100 101 230 ACES ACFT Note: Gains in the noninverting configuration are 1+ (RF/RG) and range from +1.25V/V to +101V/V. For a +1V/V gain, use the MAX4281/MAX4282/MAX4284. * Preferred Gains. These gain versions are available as samples and in small quantities. † The -3dB bandwidth is the same for inverting and noninverting configurations. 16 ______________________________________________________________________________________ SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps TOP VIEW MAX4175 MAX4281 OUT 1 5 VCC OUT 1 + VEE 2 VEE 2 + - RG R R IN+ 3 5 VCC RF VCC 4 IN+ 3 SOT23-5 4 IN- SOT23-5 MAX4281 MAX4282 N.C. 1 8 N.C. OUTA 1 MAX4274 8 VCC OUTA 1 8 VCC 7 OUTB 6 INB- 5 INB+ RF - + IN- 2 7 VCC - + INA- 2 7 OUTB INA- 2 - + + - + - IN+ 3 6 OUT INA+ 3 6 INB- INA+ 3 VEE 4 5 N.C. VEE 4 5 INB+ VEE 4 µMAX/SO µMAX/SO MAX4275 MAX4284 MAX4284 8 VCC OUTA 1 RF - + INA- 2 INA- 2 7 RF VEE 4 R 16 OUTD - + + - 13 IND- INA- 2 INA+ 3 12 IND+ INA+ 3 14 IND+ VCC 4 11 VEE VCC 4 13 VEE INB+ 5 10 INC+ INB+ 5 12 INC+ 9 INC- INB- 6 8 OUTC OUTB 7 15 IND- RG INA+ 3 R OUTA 1 OUTB 6 INB- 5 INB+ VCC R µMAX/SO INB- 6 + - + - R + - + - OUTB 7 SO/TSSOP + - VCC 14 OUTD - + RF RG SO OUTA 1 RG RG + - 11 INC10 OUTC 9 N.C. 8 N.C. QSOP ______________________________________________________________________________________ 17 MAX4174/5, MAX4274/5, MAX4281/2/4 Pin Configurations (continued) MAX4174/5, MAX4274/5, MAX4281/2/4 SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps Chip Information Ordering Information (continued) PART* TEMP. RANGE PINPACKAGE TOP MARK MAX4274_EUA MAX4274_ESA MAX4275_EUA MAX4275_ESA MAX4281EUK-T MAX4281ESA MAX4282EUA MAX4282ESA MAX4284EUD MAX4284ESD MAX4284EEE -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C -40°C to +85°C 8 µMAX 8 SO 8 µMAX 8 SO 5 SOT23-5 8 SO 8 µMAX 8 SO 14 TSSOP 14 SO 16 QSOP — — — — ACDR — — — — — — TRANSISTOR COUNTS: MAX4174: 178 MAX4175: 178 MAX4274: 332 MAX4275: 332 MAX4281: 178 MAX4282: 332 MAX4284: 328 SUBSTRATE CONNECTED TO VEE Note: Refer to Gain Selection Guide for SOT top marks. *Insert the desired gain code (from the Gain Selection Guide) in the blank to complete the part number. Refer to Gain Selection Guide for a list of preferred gains. Selector Guide INVERTING GAINS AVAILABLE (V/V) (INVERTING, RF/RG) NONINVERTING GAIN (V/V) INTERNAL RESISTORS MAX4174_ -0.25 to -100 +1.25 to +101 MAX4175_ -0.25 to -100 +1.25 to +101 MAX4274_ -0.25 to -100 MAX4275_ -0.25 to -100 PART* INTERNAL VCC/2 BIAS NO. OF AMPS PER PACKAGE Yes No 1 5-pin SOT23 Yes Yes 1 5-pin SOT23 +1.25 to +101 Yes No 2 8-pin µMAX/SO +1.25 to +101 PIN-PACKAGE Yes Yes 2 8-pin µMAX/SO MAX4281_ Open Loop, Unity-Gain Stable No No 1 5-pin SOT23, 8-pin SO MAX4282_ Open Loop, Unity-Gain Stable No No 2 8-pin µMAX/SO MAX4284_ Open Loop, Unity-Gain Stable No No 4 14-pin SO/TSSOP, 16-pin QSOP * Insert the desired gain code (from the Gain Selection Guide) in the blank to complete the part number. 18 ______________________________________________________________________________________ SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps SOT5L.EPS ______________________________________________________________________________________ 19 MAX4174/5, MAX4274/5, MAX4281/2/4 Package Information SOT23, Rail-to-Rail, Fixed-Gain GainAmps/Open-Loop Op Amps 8LUMAXD.EPS MAX4174/5, MAX4274/5, MAX4281/2/4 Package Information 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. 20 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 1999 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.