MAX4388ESD+

19-1500; Rev 0; 4/00 +3V/+5V, 250MHz, SOT23 ADC Buffer Amplifiers with High-Speed Disable Features The MAX4285/MAX4286 single and MAX4287/MAX4288/ MAX4387/MAX4388 dual ADC buffer amplifiers feature high-speed performance and single +3V supply operation. The MAX4285/MAX4286/MAX4288 and MAX4388 offer a disable feature that reduces power-supply current and places the outputs in a high-impedance state. All six devices operate from a +2.85V to +6.5V single supply or from ±1.425V to ±3.25V dual supplies. The commonmode input voltage range extends to the negative powersupply rail (ground in single-supply applications). These devices require 20mA of quiescent supply current per amplifier while achieving a 250MHz -3dB bandwidth and a 350V/µs slew rate. The combination of an 8ns (to 0.1%) settling time, 88dBc (f = 5MHz) of SFDR, and up to 100mA output drive makes these amplifiers ideal for highspeed ADC drivers for communications and instrumentation applications. In addition, when disabled, their high output impedance makes them ideal for multiplexing applications. The MAX4285/MAX4286 are available in space-saving 6-pin SOT23 and 8-pin SO packages. The MAX4287/ MAX4387 come in 8-pin µMAX and 8-pin SO packages, while the MAX4288/MAX4388 come in 10-pin µMAX and 14-pin SO packages. ♦ High Speed at 3V 250MHz -3dB Bandwidth (MAX4285/87/88) 150MHz -3dB Bandwidth (MAX4286, MAX4387/88) 350V/µs Slew Rate Applications Ordering Information ♦ +2.85V to +6.5V Single-Supply Operation ♦ Input Common-Mode Range Extends to VEE ♦ Low Distortion at 5MHz -88dBc SFDR ♦ High Output Current Drive: -106mA to +77mA ♦ 6ns Settling Time to 0.1% ♦ High-Speed Enable/Disable 40ns Enable Time 50ns Disable Time High Output Impedance ♦ Space-Saving SOT23 and µMAX Packages High-Speed ADC Drivers TEMP. RANGE PINPACKAGE SOT TOP MARK MAX4285EUT-T -40°C to +85°C 6 SOT23-6 AABQ MAX4285ESA 8 SO PART Communications Equipment Instrumentation CCD Imaging Systems Ultrasound Typical Operating Circuit appears at end of data sheet. -40°C to +85°C — MAX4286EUT-T -40°C to +85°C 6 SOT23-6 MAX4286ESA -40°C to +85°C 8 SO AABR — MAX4287EUA -40°C to +85°C 8 µMAX — MAX4287ESA -40°C to +85°C 8 SO — Ordering Information continued at end of data sheet. Pin Configurations appear at end of data sheet. Selector Guide PART OP AMPS PER PKG MIN GAIN -3dB BANDWIDTH (AT MIN GAIN) HIGH-SPEED DISABLE MAX4285 1 1 250MHz Yes MAX4286 1 5 150MHz Yes 6-pin SOT23, 8-pin SO MAX4287 2 1 250MHz No 8-pin µMAX/SO MAX4288 2 1 250MHz Yes 10-pin µMAX/14-pin SO PIN-PACKAGE 6-pin SOT23, 8-pin SO MAX4387 2 5 150MHz No 8-pin µMAX/SO MAX4388 2 5 150MHz Yes 10-pin µMAX, 14-pin SO ________________________________________________________________ Maxim Integrated Products 1 For free samples and the latest literature, visit www.maxim-ic.com or phone 1-800-998-8800. For small orders, phone 1-800-835-8769 MAX4285–MAX4288/MAX4387/MAX4388 General Description MAX4285–MAX4288/MAX4387/MAX4388 +3V/+5V, 250MHz, SOT23 ADC Buffer Amplifiers with High-Speed Disable ABSOLUTE MAXIMUM RATINGS Supply Voltage (VCC - VEE) ...................................-0.3V to +7.5V Input Voltage Range (IN+, IN-) ........(VEE - 0.3V) to (VCC + 0.3V) Differential Input Voltage .......................................-0.3V to +7.5V Voltage at DISABLE .........................(VEE - 0.3V) to (VCC + 0.3V) Current into IN+, IN-, DISABLE ........................................±20mA Output Short-Circuit Duration ........................................Indefinite Continuous Power Dissipation (TA = +70°C) 6-Pin SOT23 (derate 7.1mW/°C above +70°C)............571mW 8-Pin µMAX (derate 4.1mW/°C above +70°C) .............330mW 10-Pin µMAX (derate 5.6mW/°C above +70°C) ...........444mW 8-Pin SO (derate 5.88mW/°C above +70°C)................471mW 14-Pin SO (derate 8.3mW/°C above +70°C)................667mW 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. DC ELECTRICAL CHARACTERISTICS (VCC = +3V, VEE = 0, DISABLE_ = 3V, RL = ∞, VCM = 1V, and TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL Operating Supply Voltage Range VCM Input Offset Voltage VOS Input Offset-Voltage Temperature Coefficient TCVOS Input Offset-Voltage Matching ∆VOS Input Offset Current Input Resistance Common-Mode Rejection Ratio Open-Loop Gain 2 Guaranteed by PSRR test Input Common-Mode Voltage Range Input Bias Current CONDITIONS Guaranteed by CMRR test MIN TYP MAX UNITS 2.85 6.5 V VEE VCC 1.25 V MAX4_87EU_/MAX4_88EU_/MAX4_8_ES_ ±0.1 ±8 MAX4285EUT-T/MAX4286EUT-T ±1.5 ±12 MAX4287/88 and MAX4387/88 mV 26 µV/°C ±0.2 mV IB 13 35 µA IOS 0.2 8 µA RIN CMRR AVOL Differential (-10mV ≤ VIN ≤ +10mV) 38 Common mode (VEE ≤ VCM ≤ VCC - 1.25V) 600 VEE ≤ VCM ≤ VCC - 1.25V VEE + 0.4V ≤ VOUT ≤ VCC - 0.4V MAX4_87EU_/ MAX4_88EU_/ MAX4_8_ES_ 50 MAX4285EUT-T/ MAX4286EUT-T 45 kΩ 73 dB RL = 2kΩ 75 94 RL = 300Ω 65 94 RL = 100Ω 60 85 _______________________________________________________________________________________ 68 dB +3V/+5V, 250MHz, SOT23 ADC Buffer Amplifiers with High-Speed Disable (VCC = +3V, VEE = 0, DISABLE_ = 3V, RL = ∞, VCM = 1V, and TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP RL = 20Ω to VEE 77 RL = 20Ω to VCC 106 Output Current Drive IOUT Power-Supply Rejection Ratio PSRR VCC = 2.85V to 6.5V Disabled Output Leakage Current ILEAK DISABLE_ = VEE, VEE ≤ VOUT ≤ VCC 40 MAX UNITS mA 50 dB 700 nA VCC - 2 DISABLE_ Logic Low Threshold VIL DISABLE_ Logic High Threshold VIH DISABLE_ Logic Input Low Current IIL DISABLE_ = VEE ±3 ±22 µA DISABLE_ Logic Input High Current IIH DISABLE_ = VCC ±3 ±22 µA Normal mode 20 24 Disabled mode, DISABLE_ = VEE 1 3 Normal mode 23 28 Disabled mode, DISABLE_ = VEE 1 3 VCC - 1 VCC = 3V Quiescent Supply Current (per Amplifier) ISY VCC = 5V V V mA _______________________________________________________________________________________ 3 MAX4285–MAX4288/MAX4387/MAX4388 DC ELECTRICAL CHARACTERISTICS (continued) MAX4285–MAX4288/MAX4387/MAX4388 +3V/+5V, 250MHz, SOT23 ADC Buffer Amplifiers with High-Speed Disable AC ELECTRICAL CHARACTERISTICS (VCC = +3V, VEE = 0, DISABLE_ = 3V, RL = 300Ω to VCC/2, VCM = 1V, AVCL = +1V/V for MAX4285/MAX4287/MAX4288, AVCL = +5V/V for MAX4286 and MAX4387/MAX4388, TA = +25°C, unless otherwise noted.) PARAMETER SYMBOL Small-Signal -3dB Bandwidth BWSS VOUT = 100mVp-p Large-Signal -3dB Bandwidth BWLS VOUT = 1Vp-p Bandwidth for 0.1dB Flatness BW0.1dB VOUT = 100mVp-p MIN TYP MAX4285/87/88 250 MAX4286 and MAX4387/88 150 200 MAX4285/87/88 100 MAX4286 and MAX4387/88 50 MAX UNITS MHz MHz MHz Slew Rate SR VOUT = 1V step, 10% to 90% 350 V/µs Rise Time tR VOUT = 1V step, 10% to 90% 2.2 ns Fall Time tF VOUT= 1V step, 90% to 10% 2.8 ns Settling Time (0.1%) tS 0.1% Overload Recovery Time Spurious-Free Dynamic Range Two-Tone Third-Order Intercept VOUT = 1V step MAX4285/87/88 6 MAX4286 and MAX4387/88 14 25 10% overdrive SFDR Input Noise Voltage Density IP3 en Input Noise Current Density in Input Capacitance CIN Output Impedance ZOUT VOUT = 0.5Vp-p fC = 100kHz 88 fC = 1MHz 88 fC = 5MHz 87 fC = 10MHz 79 fC = 20MHz 70 fC = 60MHz 50 ns dBc 34 f = 1MHz 10 nV/√Hz f = 1MHz 2.1 pA/√Hz 2 pF f = 10MHz 0.5 Ω tON VOUT = 1V, to within 0.1% 40 Disable Time tOFF VOUT = 1V, to within 0.1% 50 MAX4287/88 and MAX4387/88, f = 10MHz, VOUT = 1Vp-p 85 XTALK ns fC = 20MHz Enable Time Crosstalk 4 CONDITIONS _______________________________________________________________________________________ dBm ns dBc +3V/+5V, 250MHz, SOT23 ADC Buffer Amplifiers with High-Speed Disable (VCC = +5V, VEE = 0, DISABLE_ = 5V, RL = 300Ω to VCC/2, VCM = 2.5V, AVCL = +1V/V for MAX4285/MAX4287/MAX4288, AVCL = +5V/V for MAX4286 and MAX4387/MAX4388, TA = +25°C, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS Small-Signal -3dB Bandwidth BWSS VOUT = 100mVp-p Large-Signal -3dB Bandwidth BWLS VOUT = 1Vp-p Bandwidth for 0.1dB Flatness BW0.1dB VOUT = 100mVp-p MIN TYP MAX4285/87/88 220 MAX4286 and MAX4387/88 130 195 MAX4285/87/88 75 MAX4286 and MAX4387/88 40 MAX UNITS MHz MHz MHz Slew Rate SR VOUT = 2V step, 10% to 90% 385 V/µs Rise Time tR VOUT = 2V step, 10% to 90% 4.2 ns Fall Time tF VOUT= 2V step, 90% to 10% 2.9 ns Settling Time (0.1%) Spurious-Free Dynamic Range tS 0.1% SFDR VOUT = 2V step VOUT = 1Vp-p MAX4285/87/88 8 MAX4286 and MAX4387/88 10 fC = 100kHz 86 fC = 1MHz 86 fC = 5MHz 86 fC = 10MHz 77 fC = 20MHz 64 fC = 60MHz 45 ns dBc Two-Tone Third-Order Intercept IP3 fC = 20MHz 40 dBm Input Noise Voltage Density en f = 1MHz 6.5 nV/√Hz Input Noise Current Density in f = 1MHz 1.9 pA/√Hz 2 pF f = 10MHz 0.5 Ω Input Capacitance CIN Output Impedance ZOUT Enable Time tON VOUT = 1V, to within 0.1% 40 Disable Time tOFF VOUT = 1V, to within 0.1% 35 MAX4287/88 and MAX4387/88, f = 10MHz, VOUT = 2Vp-p 85 Crosstalk XTALK ns dBc Note 1: The MAX428_EUT (SOT23) are 100% production tested at TA = +25°C. Specifications over temperature limits are guaranteed by design. _______________________________________________________________________________________ 5 MAX4285–MAX4288/MAX4387/MAX4388 AC ELECTRICAL CHARACTERISTICS (continued) Typical Operating Characteristics (VCC = +3V, VEE = 0, DISABLE_ ≥ 2V, RL = 300Ω to VCC/2, VCM = +1.0V, TA =+25°C, unless otherwise noted.) 0.2 0 0 0.1 -1 -2 -3 -3 -0.2 -4 -4 -0.3 -5 -5 -0.4 -6 100k -6 100k 1M 10M 100M 1G 1M 10M 100M -0.5 100k 1G 1M 10M 100M FREQUENCY (Hz) FREQUENCY (Hz) FREQUENCY (Hz) MAX4285/MAX4287/MAX4288 GAIN FLATNESS vs. FREQUENCY (RLOAD = 300Ω) MAX4285/MAX4287/MAX4288 GAIN FLATNESS vs. FREQUENCY (RLOAD = 1kΩ) MAX4286/MAX4387/MAX4388 GAIN FLATNESS vs. FREQUENCY AV = +1V/V 0.4 0.1 0.2 0.1 0 0.1 0 GAIN (dB) 0.2 GAIN (dB) 0.3 -0.2 0 -0.1 -0.2 -0.3 -0.3 -0.4 -0.5 -0.4 -0.5 -0.6 100k -0.5 100k 100M 1G 1M 10M 100M RLOAD = 300Ω RLOAD = 1kΩ -0.2 -0.4 10M RLOAD = 100Ω -0.1 -0.3 1M AV = +5V/V 0.3 0.2 -0.1 -0.6 100k 1G 1M 10M 100M FREQUENCY (Hz) FREQUENCY (Hz) LARGE-SIGNAL GAIN vs. FREQUENCY MAX4285/MAX4287/MAX4288 DISTORTION vs. FREQUENCY MAX4286/MAX4387/MAX4388 DISTORTION vs. FREQUENCY -50 2 1 RL = 300Ω VOUT = 0.5Vp-p AV = +1V/V -50 GAIN (dB) -1 -2 -70 -80 -3 RL = 300Ω VOUT = 0.5Vp-p AV = +5V/V -60 GAIN (dB) -60 0 -70 -80 2ND HARMONIC 2ND HARMONIC -4 -90 -90 -5 -6 100k -40 MAX4285-08 -40 MA4285-07 3 3RD HARMONIC 3RD HARMONIC -100 1M 10M FREQUENCY (Hz) 100M 1G 1G MAX4285-09 FREQUENCY (Hz) 4 1G 0.4 MA4285-05 0.5 MA4285-04 AV = +1V/V MA4285-03 0 -0.1 MA4285-06 -2 GAIN (dB) 1 GAIN (dB) GAIN (dB) 0.3 1 -1 AV = +1V/V 0.4 2 0.3 6 0.5 2 0.4 GAIN (dB) AV = +5V/V 3 MA4285-02 AV = +1V/V 3 4 MA4285-01 4 MAX4285/MAX4387/MAX4288 GAIN FLATNESS vs. FREQUENCY (RLOAD = 100Ω) MAX4286/MAX4387/MAX4388 SMALL-SIGNAL GAIN vs. FREQUENCY MAX4285/MAX4287/MAX4288 SMALL-SIGNAL GAIN vs. FREQUENCY GAIN (dB) MAX4285–MAX4288/MAX4387/MAX4388 +3V/+5V, 250MHz, SOT23 ADC Buffer Amplifiers with High-Speed Disable -100 0.1 1 10 FREQUENCY (MHz) 100 0.1 1 10 FREQUENCY (MHz) _______________________________________________________________________________________ 100 +3V/+5V, 250MHz, SOT23 ADC Buffer Amplifiers with High-Speed Disable -50 -40 2ND HARMONIC -70 -80 -90 3RD HARMONIC 2ND HARMONIC -60 DISTORTION (dBc) 2ND HARMONIC RL = 300Ω fO = 20MHz AV = +1V/V -50 -60 DISTORTION (dBc) -60 DISTORTION (dBc) fO = 20MHz VOUT = 0.5Vp-p AV = +5V/V MAX4285/MAX4287/MAX4288 DISTORTION vs. SWING MAX4285-13 fO = 20MHz VOUT = 0.5Vp-p AV = +1V/V -50 -40 MAX4285-11 -40 MAX4286/MAX4387/MAX4388 DISTORTION vs. LOAD MAX4285-12 MAX4285/MAX4287/MAX4288 DISTORTION vs. LOAD -70 -80 3RD HARMONIC -90 -70 -80 -90 -100 -100 -100 -110 -110 -110 -120 -120 -120 3RD HARMONIC 100 200 300 400 500 600 700 800 900 1000 100 200 300 400 500 600 700 800 900 1000 RESISTIVE LOAD (Ω) RESISTIVE LOAD (Ω) VOLTAGE (Vp-p) MAX4286/MAX4387/MAX4388 DISTORTION vs. SWING MAX4285/MAX4286/MAX4288/MAX4388 OFF-ISOLATION vs. FREQUENCY MAX4287/MAX4288/MAX4387/MAX4388 CROSSTALK vs. FREQUENCY -80 3RD HARMONIC -90 20 -20 -40 0 -40 -60 -80 -80 -110 -100 -100 -120 -120 100k 0.25 0.50 0.75 1.00 1.25 -120 1M 10M 100M 1G FREQUENCY (Hz) VOLTAGE (Vp-p) 1 10 100 1000 MAX4286/MAX4387/MAX4388 LARGE-SIGNAL PULSE RESPONSE (AV = +5V/V) MA4285-17 INPUT 100mV/ div VOLTAGE (V) INPUT 500mV/ div 0.1 FREQUENCY (MHz) MAX4285/MAX4287/MAX4288 LARGE-SIGNAL PULSE RESPONSE (AV = +1V/V) VOLTAGE (V) 0 1.25 -20 -60 -100 1.00 MAX4285-16 40 20 0 0.75 MA4285-18 -70 0.50 60 40 GAIN (dB) OFF-ISOLATION 2ND HARMONIC -60 DISTORTION (dBc) 60 0.25 80 MA4285-15 RL = 300Ω fO = 20MHz AV = +5V/V -50 80 MAX4285-14 -40 0 OUTPUT 500mV/ div OUTPUT 500mV/ div TIME (5ns/div) TIME (5ns/div) _______________________________________________________________________________________ 7 MAX4285–MAX4288/MAX4387/MAX4388 Typical Operating Characteristics (continued) (VCC = +3V, VEE = 0, DISABLE_ ≥ 2V, RL = 300Ω to VCC/2, VCM = +1.0V, TA =+25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VCC = +3V, VEE = 0, DISABLE_ ≥ 2V, RL = 300Ω to VCC/2, VCM = +1.0V, TA =+25°C, unless otherwise noted.) MAX4285/MAX4287/MAX4288 SMALL-SIGNAL PULSE RESPONSE (AV = +1V/V) MAX4285/MAX4287/MAX4288 SMALL-SIGNAL PULSE RESPONSE (CLOAD = 22pF, AV = +1V/V) OUTPUT 50mV/ div MA4285-21 INPUT 10mV/ div VOLTAGE (V) INPUT 50mV/ div VOLTAGE (V) VOLTAGE (V) MA4285-20 MA4285-19 MAX4286/MAX4387/MAX4388 SMALL-SIGNAL PULSE RESPONSE (AV = +5V/V) INPUT 50mV/ div OUTPUT 50mV/ div OUTPUT 50mV/ div TIME (5ns/div) TIME (5ns/div) TIME (5ns/div) MAX4286/MAX4387/MAX4388 SMALL-SIGNAL PULSE RESPONSE (CLOAD = 47pF, AV = +5V/V) ISOLATION RESISTANCE vs. LOAD CAPACITANCE GROUP DELAY vs. FREQUENCY 22 1.8 1.6 1.4 MAX4286/MAX4387/MAX4388 AV = +5V/V 18 TIME (ns) RISO (Ω) VOLTAGE (V) 20 16 14 OUTPUT 50mV/ div 1.2 1.0 0.8 0.6 MAX4285/87/88 AV = +1V/V 12 0.4 0.2 0 100k 10 TIME (5ns/div) MA4285-26 2.0 MAX4285-23 24 MA4285-22 INPUT 10mV/ div 40 70 100 130 160 190 220 250 1M CLOAD (pF) COMMON-MODE REJECTION vs. FREQUENCY -10 100M -10 -20 10 CMR (dB) -30 -40 IMPEDANCE (Ω) -30 -20 1G OUTPUT IMPEDANCE vs. FREQUENCY 100 MA4285-28 0 MA4285-27 0 10M FREQUENCY (Hz) MAX4285-29 POWER-SUPPLY REJECTION RATIO vs. FREQUENCY PSRR (dB) MAX4285–MAX4288/MAX4387/MAX4388 +3V/+5V, 250MHz, SOT23 ADC Buffer Amplifiers with High-Speed Disable -40 -50 -60 1 -70 0.1 -80 -50 -90 -60 100k 1M 10M FREQUENCY (Hz) 8 100M 1G -100 100k 0.01 1M 10M FREQUENCY (Hz) 100M 1G 10k 100k 1M 10M FREQUENCY (Hz) _______________________________________________________________________________________ 100M 1G +3V/+5V, 250MHz, SOT23 ADC Buffer Amplifiers with High-Speed Disable 10 MAX4285-32 19 INPUT BIAS CURRENT (µA) NOISE (pA/√Hz) 10 20 MAX4285-31 100 MAX4285-30 100 VOLTAGE NOISE (nv/√Hz) INPUT BIAS CURRENT vs. TEMPERATURE CURRENT NOISE DENSITY vs. FREQUENCY VOLTAGE NOISE DENSITY vs. FREQUENCY 18 17 16 15 14 13 12 11 100 1k 10k 100k 1M 1 10M 10 100 1k 10k 100k 1M -50 -35 -20 -5 10 25 40 55 70 85 100 10M FREQUENCY (Hz) FREQUENCY (Hz) TEMPERATURE (°C) INPUT OFFSET CURRENT vs. TEMPERATURE INPUT OFFSET VOLTAGE vs. TEMPERATURE POWER-SUPPLY CURRENT vs. TEMPERATURE INPUT OFFSET VOLTAGE (mV) 0.4 0.3 0.2 0.1 3 2 1 0 -1 -2 -3 22 MAX4285-35 4 POWER-SUPPLY CURRENT (mA) 5 MAX4285-33 0.5 MAX4285-34 10 INPUT OFFSET CURRENT (µA) 10 1 1 21 20 19 -4 -5 0 -50 -35 -20 -5 10 25 40 55 70 85 100 TEMPERATURE (°C) TEMPERATURE (°C) TEMPERATURE (°C) MAX4286 SMALL-SIGNAL GAIN vs. FREQUENCY (CLOAD = 22pF) MAX4286 SMALL-SIGNAL GAIN vs. FREQUENCY (CLOAD = 37pF) MAX4286 SMALL-SIGNAL GAIN vs. FREQUENCY (CLOAD = 47pF) AV = +5V/V 8 10 MA4285-40 8 10 MA4285-39 AV = +5V/V 4 4 4 2 2 2 -2 GAIN (dB) 6 GAIN (dB) 6 0 0 -2 0 -2 -4 -4 -4 -6 -6 -6 -8 -8 -10 100k 1M 10M FREQUENCY (Hz) 100M 1G -10 100k AV = +5V/V 8 6 MA4285-41 -50 -35 -20 -5 10 25 40 55 70 85 100 10 GAIN (dB) 18 -50 -35 -20 -5 10 25 40 55 70 85 100 -8 1M 10M FREQUENCY (Hz) 100M 1G -10 100k 1M 10M 100M 1G FREQUENCY (Hz) _______________________________________________________________________________________ 9 MAX4285–MAX4288/MAX4387/MAX4388 Typical Operating Characteristics (continued) (VCC = +3V, VEE = 0, DISABLE_ ≥ 2V, RL = 300Ω to VCC/2, VCM = +1.0V, TA =+25°C, unless otherwise noted.) Typical Operating Characteristics (continued) (VCC = +3V, VEE = 0, DISABLE_ ≥ 2V, RL = 300Ω to VCC/2, VCM = +1.0V, TA =+25°C, unless otherwise noted.) 1.5 2.5 AV = +5V/V RISO = 22Ω 2.0 1.5 1.5 0.5 -0.5 GAIN (dB) 1.0 0.5 GAIN (dB) 1.0 0.5 0 0 -0.5 0 -0.5 -1.0 -1.0 -1.0 -1.5 -1.5 -1.5 -2.0 -2.0 -2.0 -2.5 100k -2.5 100k 10M 100M 1G 1M 10M 100M 1G -2.5 100k MA4285-45 VEE + 1V 10M ENABLE/DISABLE RESPONSE TIME (VCC = 3V) ENABLE/DISABLE RESPONSE TIME (VCC = 5V) VCC - 1V 1M FREQUENCY (Hz) FREQUENCY (Hz) MA4285-46 1M AV = +5V/V RISO = 25Ω 2.0 1.0 FREQUENCY (Hz) VCC - 1V VEE + 1V TIME (20ns/div) 10 2.5 MA4285-43 AV = +5V/V RISO = 15Ω 2.0 MA4285-42 2.5 MAX4286 SMALL-SIGNAL GAIN vs. FREQUENCY CLOAD || RISO (CLOAD = 37pF) MAX4286 SMALL-SIGNAL GAIN vs. FREQUENCY CLOAD || RISO (CLOAD = 37pF) MA4285-44 MAX4286 SMALL-SIGNAL GAIN vs. FREQUENCY CLOAD || RISO (CLOAD = 37pF) GAIN (dB) MAX4285–MAX4288/MAX4387/MAX4388 +3V/+5V, 250MHz, SOT23 ADC Buffer Amplifiers with High-Speed Disable TIME (20ns/div) ______________________________________________________________________________________ 100M 1G +3V/+5V, 250MHz, SOT23 ADC Buffer Amplifiers with High-Speed Disable PIN MAX4285 MAX4286 MAX4287 MAX4387 MAX4288 MAX4388 NAME FUNCTION 6-PIN SOT23-6 8-PIN SO 8-PIN µMAX/SO 10-PIN µMAX 14-PIN SO — 1, 5 — — 5, 7, 8, 10 N.C. Not Internally Connected. Connect to ground or leave unconnected. 1 6 — — — OUT Amplifier Output 2 4 4 4 4 VEE Negative Power Supply, or Ground in Single-Supply Operation 3 3 — — — IN+ Noninverting Input 4 2 — — — IN- Inverting Input 5 8 — — — DISABLE — — — 5 6 DISABLEA Disable Amplifier A (active low) — — — 6 9 DISABLEB Disable Amplifier B (active low) 6 7 8 10 14 VCC — — 1 1 1 OUTA — — 2 2 2 INA- Amplifier A Inverting Input — — 3 3 3 INA+ Amplifier A Noninverting Input — — 5 7 11 INB+ Amplifier B Noninverting Input — — 6 8 12 INB- Amplifier B Inverting Input — — 7 9 13 OUTB Detailed Description The MAX4285–MAX4288 and MAX4387/MAX4388 are voltage-feedback op amps, intended for use as ADC input buffers. They operate from a single +2.85V to +6.5V supply or dual ±1.425V to ±3.25V supplies. Their high output drive, wide bandwidth, fast settling, low noise, and low distortion make them ideal for the brutal task of meeting the dynamic input drive requirements of high-speed ADCs or other demanding applications. The MAX4285/MAX4286/MAX4288 and MAX4388 have a high-speed disable mode that places the outputs in a high-impedance state and lowers operating supply current to 1mA. The enable time is typically 40ns, and the disable time is typically 50ns. The MAX4285/MAX4286 have a single enable pin (DISABLE), and the MAX4288/ Disable (active low) Positive Power Supply Amplifier A Output Amplifier B Output MAX4388 have dual disable pins (DISABLEA, DISABLEB). The MAX4285/MAX4287/MAX4288 are internally compensated for unity-gain stability. The MAX4286/ MAX4387/MAX4388 are compensated for gains of +5V/V or greater. Applications Information Inverting and Noninverting Configurations Select the gain-setting feedback (RF) and input (RG) resistor values considering the following criteria: large resistor values increase voltage noise and interact with the amplifier’s input and PC board capacitance to effect system bandwidth. This generates undesirable poles and zeros that decrease bandwidth or cause oscillations. ______________________________________________________________________________________ 11 MAX4285–MAX4288/MAX4387/MAX4388 Pin Description MAX4285–MAX4288/MAX4387/MAX4388 +3V/+5V, 250MHz, SOT23 ADC Buffer Amplifiers with High-Speed Disable For example, a noninverting gain-of-two configuration (RF = RG) using 1kΩ resistors, combined with 2pF typical amplifier input capacitance, generates a pole at 159MHz. Since this pole is within the amplifier bandwidth, it jeopardizes stability. Reducing these 1kΩ resistors to 100Ω extends the pole frequency to 1.59GHz, but affects output swing by adding 200Ω in parallel with the amplifier’s load resistor. The typical value for RF is 300Ω. Layout and Power-Supply Bypassing These amplifiers operate from a single +2.85V to +6.5V power supply or from ±1.425V to ±3.25V dual supplies. For single-supply operation, bypass VCC to ground with a 0.1nF capacitor as close to the pin as possible, with a 0.1µF capacitor in parallel. If operating with dual supplies, bypass each supply with capacitors to ground. Observe the following guidelines: • A solid ground plane is essential for good high-frequency behavior. • • Where possible, use multiple ground vias. Use a PC board with at least two layers. Avoid areas of unreferenced copper-clad. Keep signal traces as short and as straight as possible. Do not make sharp turns; round all trace corners. Use a constant-impedance board design if possible. • • Output Capacitive Loading and Stability These op amps are optimized for AC performance. They are not designed to drive highly reactive loads, which decrease phase margin and may produce excessive ringing and oscillation. A small isolation resistor (usually 20Ω to 30Ω) placed before the reactive load reduces possible ringing and oscillation (Figure 1). At higher capacitive loads, AC performance is dependent on the interaction of the load capacitance, the isolation resistor, and on-board layout. Output Drive Capability The MAX4285–MAX4288 and MAX4387/MAX4388 have an output sink capability of 106mA and a source capability of 77mA. This high current ability allows them to drive low-impedance and dynamic-impedance ADC inputs. The linear output range of these devices is (VEE + 0.4V) to (VCC - 0.4V). Operation beyond this range is not recommended due to reduced gain and phase margin. RG RF RS CI CI High-Speed Disable The MAX4285/MAX4286/MAX4288 and MAX4388 feature a disable (DISABLE_) input that places the amplifier in a low-power, high-output-impedance state. When DISABLE_ is asserted, the amplifier’s output impedance is typically 35kΩ. This high output impedance, combined with the low 2pF output capacitance, make these devices ideal for ADC input multiplexing applications or switch applications. Typical enable/disable times are 40ns/50ns. 12 MAX4285 MAX4286 MAX4287 MAX4288 MAX4387 MAX4388 Figure 1. Using an Isolation Resistor (RS ) for High Capacitive Loads ______________________________________________________________________________________ +3V/+5V, 250MHz, SOT23 ADC Buffer Amplifiers with High-Speed Disable PART TEMP. RANGE PINPACKAGE SOT TOP MARK MAX4288EUB -40°C to +85°C 10 µMAX — MAX4288ESD -40°C to +85°C 14 SO — MAX4387EUA -40°C to +85°C 8 µMAX — MAX4387ESA -40°C to +85°C 8 SO — MAX4388EUB -40°C to +85°C 10 µMAX — MAX4388ESD -40°C to +85°C 14 SO — RG RF MAX157 A/D CONVERTER VIN MAX4285 MAX4286 MAX4287 MAX4288 MAX4387 MAX4388 Chip Information TRANSISTOR COUNT: MAX4285/MAX4286 : 114 MA4287/MAX4288/ MAX4387/MAX4388 : 227 Pin Configurations TOP VIEW MAX4285 MAX4286 MAX4285 MAX4286 OUT 1 6 VCC VEE VEE 2 5 DISABLE IN+ IN+ 3 4 IN- MAX4287 MAX4387 N.C. 1 8 DISABLE IN- 2 7 3 VEE 4 IN+ OUTA 1 8 VCC VCC INA- 2 7 OUTB 6 OUT INA+ 3 6 INB- 5 N.C. VEE 4 5 INB+ 8-PIN SO 6-PIN SOT23 8-PIN SO/µMAX MAX4288 MAX4388 MAX4288 MAX4388 10 VCC OUTA 1 INAINA+ 2 9 3 8 6 DISABLEA 5 10-PIN µMAX 14 VCC OUTB INA- 2 13 OUTB INB- INA+ 3 12 INB- VEE 4 11 INB+ N.C. 5 10 N.C. 7 INB+ VEE 4 OUTA 1 DISABLEB DISABLEA 6 9 DISABLEB N.C. 7 8 N.C. 14-PIN SO ______________________________________________________________________________________ 13 MAX4285–MAX4288/MAX4387/MAX4388 Typical Operating Circuit Ordering Information (continued) +3V/+5V, 250MHz, SOT23 ADC Buffer Amplifiers with High-Speed Disable 8LUMAXD.EPS 6LSOT.EPS MAX4285–MAX4288/MAX4387/MAX4388 Package Information 14 ______________________________________________________________________________________ +3V/+5V, 250MHz, SOT23 ADC Buffer Amplifiers with High-Speed Disable 10LUMAX.EPS ______________________________________________________________________________________ 15 MAX4285–MAX4288/MAX4387/MAX4388 Package Information (continued) +3V/+5V, 250MHz, SOT23 ADC Buffer Amplifiers with High-Speed Disable SOICN.EPS MAX4285–MAX4288/MAX4387/MAX4388 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. 16 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2000 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.