MAX4475 MAX4478/ MAX4488/MAX4489. SOT23, Low-Noise, Low-Distortion, Wide-Band, Rail-to-Rail Op Amps

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1 Click here for production status of specific part numbers. MAX7 MAX78/ General Description The MAX7 MAX78/ wideband, low-noise, low-distortion operational amplifiers offer rail-to-rail outputs and single-supply operation down to.7v. They draw.ma of quiescent supply current per amplifier while featuring ultra-low distortion (.% THD+N), as well as low input voltage-noise density (.nv/ Hz) and low input current-noise density (.fa/ Hz). These features make the devices an ideal choice for applications that require low distortion and/or low noise. For power conservation, the MAX7/MAX88 offer a low-power shutdown mode that reduces supply current to.1µa and places the amplifiers outputs into a high-impedance state. These amplifiers have outputs which swing rail-to-rail and their input common-mode voltage range includes ground. The MAX7 MAX78 are unity-gain stable with a gain-bandwidth product of 1MHz. The MAX88/89 are internally compensated for gains of +V/V or greater with a gain-bandwidth product of MHz. The single MAX7/MAX7/ MAX88 are available in space-saving, -pin SOT3 and TDFN packages. Applications ADC Buffers DAC Output Amplifiers Low-Noise Microphone/Preamplifiers Digital Scales Strain Gauges/Sensor Amplifiers Medical Instrumentation µmax is a registered trademark of Maxim Integrated Products, Inc. Features Low Input Voltage-Noise Density:.nV/ Hz Low Input Current-Noise Density:.fA/ Hz Low Distortion:.% THD+N (1kΩ load) Single-Supply Operation from +.7V to +.V Input Common-Mode Voltage Range Includes Ground Rail-to-Rail Output Swings with a 1kΩ Load 1MHz GBW Product, Unity-Gain Stable (MAX7 MAX78) MHz GBW Product, Stable with AV +V/V () Excellent DC Characteristics V OS = 7µV I BIAS = 1pA Large-Signal Voltage Gain = 1dB Low-Power Shutdown Mode: Reduces Supply Current to.1µa Places Output in High-Impedance State Available in Space-Saving SOT3, TDFN, µmax, and TSSOP Packages AEC-Q1 Qualified, Refer to Ordering Information for the List of /V Parts Ordering Information at end of data sheet. Typical Operating Characteristic VIN EQUIVALENT INPUT NOISE VOLTAGE (nv Hz) 1 1 INPUT VOLTAGE-NOISE DENSITY vs. FREQUENCY 1 1 1k 1k 1k FREQUENCY (Hz) MAX7 toc Pin Configurations and Typical Operating Circuit appear at end of data sheet ; Rev 9; 7/18

2 Absolute Maximum Ratings Power-Supply Voltage (V DD to V SS )...-.3V to +.V Analog Input Voltage (IN_+, IN_-)..(V SS -.3V) to (V DD +.3V) SHDN Input Voltage...(V SS -.3V) to +.V Output Short-Circuit Duration to Either Supply...Continuous Continuous Input Current (IN+, IN-)...±1mA Continuous Power Dissipation (T A = +7 C) -Pin SOT3 (derate.mw/ C above +7 C) mW -Pin TDFN (derate 18.mW/ C above 7 C)...1mW 8-Pin µmax (derate.mw/ C above +7 C)...3mW 8-Pin SO (derate.88mw/ C above +7 C)...71mW 1-Pin SO (derate 8.33mW/ C above +7 C)...7mW 1-Pin TSSOP (derate 9.1mW/ C above +7 C)...77mW Operating Temperature Range... - C to +1 C Junction Temperature...+1 C Storage Temperature Range... - C to +1 C Lead Temperature (soldering, 1s)...+3 C Soldering Temperature (reflow)...+ 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 (V DD = +V, V SS = V, V CM = V, = V DD /, R L tied to V DD /, SHDN = V DD, T A = - C to +1 C, unless otherwise noted. Typical values are at T A = + C.) (Notes 1, ) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Supply Voltage Range V DD (Note 3).7. V Quiescent Supply Current Per Amplifier I D Normal mode V DD = 3V. V DD = V.. Shutdown mode (SHDN = V SS ) (Note ).1 1. µa T A = + C ±7 ±3 Input Offset Voltage V OS T A = - C to +1 C ±7 Input Offset Voltage Tempco TC VOS ±.3 ± µv/ C Input Bias Current I B (Note ) ±1 ±1 pa Input Offset Current I OS (Note ) ±1 ±1 pa Differential Input Resistance R IN 1 GΩ Input Common-Mode Voltage Range Common-Mode Rejection Ratio V CM CMRR Guaranteed by CMRR Test (V SS -.V) V CM (V DD 1.V) (V SS -.1V) V CM (V DD 1.7V) T A = + C -. V DD - 1. T A = - C to +1 C -.1 V DD T A = + C 9 11 T A = - C to +1 C 9 Power-Supply Rejection Ratio PSRR V DD =.7 to.v 9 1 db R L = 1kW to V DD /; = 1mV to (V DD - 1mV) 9 1 ma µv V db Large-Signal Voltage Gain A VOL R L = 1kW to V DD /; = mv to (V DD - mv) 8 11 db RL = W to V DD /; = 3mV to (V DD - mv) Maxim Integrated

3 DC Electrical Characteristics (continued) (V DD = +V, V SS = V, V CM = V, = V DD /, R L tied to V DD /, SHDN = V DD, T A = - C to +1 C, unless otherwise noted. Typical values are at T A = + C.) (Notes 1, ) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Output Voltage Swing V IN+ - V IN- 1mV, R L = 1kW to V DD / V IN+ - VIN- 1mV, R L = 1kW to V DD / V IN+ - V IN- 1mV, R L = W to V DD / V DD - V OH 1 V OL - V SS 1 V DD - V OH 8 V OL - V SS 1 V DD - V OH 1 3 V OL - V SS 8 Output Short-Circuit Current I SC 8 ma Output Leakage Current I LEAK Shutdown mode (SHDN = V SS ), = V SS to V DD ±.1 ±1. µa SHDN Logic Low V IL.3 x V DD V SHDN Logic High V IH.7 x V DD V SHDN Input Current SHDN = V SS to V DD.1 1 µa Input Capacitance C IN 1 pf mv AC Electrical Characteristics (V DD = +V, V SS = V, V CM = V, = V DD /, R L tied to V DD /, SHDN = V DD, T A = + C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Gain-Bandwidth Product Slew Rate Full-Power Bandwidth (Note ) GBWP SR MAX7 MAX78 A V = +1V/V 1 A V = +V/V MAX7 MAX78 A V = +1V/V 3 A V = +V/V 1 MAX7 MAX78 A V = +1V/V. A V = +V/V 1. Peak-to-Peak Input Noise Voltage e n(p-p) f =.1Hz to 1Hz nvp-p Input Voltage-Noise Density e n f = 1kHz. nv/ Hz f = 1Hz 1 f = 3kHz 3. Input Current-Noise Density i n f = 1kHz. fa/ Hz = V P-P, A V = +1V/V (MAX7 MAX78), R L = 1kW to GND f = 1kHz. f = khz.7 MHz V/µs MHz Total Harmonic Distortion Plus Noise (Note ) THD + N = V P-P, A V = +1V/V (MAX7 MAX78), R L = 1kW to GND f = 1kHz. f = khz.1 % = V P-P, A V = +V/V (MAX88/ MAX89), R L = 1kW to GND f = 1kHz. f = khz. Maxim Integrated 3

4 AC Electrical Characteristics (V DD = +V, V SS = V, V CM = V, = V DD /, R L tied to V DD /, SHDN = V DD, T A = + C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Total Harmonic Distortion Plus Noise (Note ) THD + N = V P-P, A V = +V/V (), R L = 1kW to GND f = 1kHz. f = khz.8 % Capacitive-Load Stability No sustained oscillations pf Gain Margin GM 1 db Phase Margin FM MAX7 MAX78, A V = +1V/V 7, A V = +V/V 8 Settling Time To., = V step µs Delay Time to Shutdown t SH 1. µs Enable Delay Time from Shutdown t EN =.V, settles to. 1 µs Power-Up Delay Time V DD = to V step, stable to. 13 µs Note 1: All devices are tested at T A = + C. Limits over temperature are guaranteed by design. Note : SHDN is available on the MAX7/MAX88 only. Note 3: Guaranteed by the PSRR test. Note : Guaranteed by design. Note : Full-power bandwidth for unity-gain stable devices (MAX7 MAX78) is measured in a closed-loop gain of +V/V to accommodate the input voltage range, = V P-P. Note : Lowpass-filter bandwidth is khz for f = 1kHz and 8kHz for f = khz. Noise floor of test equipment = 1nV/ Hz. degrees Typical Operating Characteristics (V DD = +V, V SS = V, V CM = V, = V DD /, R L tied to V DD /, input noise floor of test equipment =1nV/ Hz for all distortion measurements, T A = + C, unless otherwise noted.) PERCENTAGE OF UNITS (%) INPUT OFFSET VOLTAGE DISTRIBUTION V OS (µv) MAX7-8 toc1 INPUT OFFSET VOLTAGE (µv) OFFSET VOLTAGE vs. TEMPERATURE V COM = V TEMPERATURE ( C) MAX7 toc INPUT OFFSET VOLTAGE (µv) 3 1 INPUT OFFSET VOLTAGE vs. INPUT COMMON-MODE VOLTAGE V DD = 3V V DD = V INPUT COMMON-MODE VOLTAGE (V) MAX7 toc3 Maxim Integrated

5 Typical Operating Characteristics (continued) (V DD = +V, V SS = V, V CM = V, = V DD /, R L tied to V DD /, input noise floor of test equipment =1nV/ Hz for all distortion measurements, T A = + C, unless otherwise noted.).. OUTPUT VOLTAGE vs. OUTPUT LOAD CURRENT V DD = 3V OR V V DIFF = 1mV MAX7 toc 7 OUTPUT VOLTAGE SWING (V OH ) vs. TEMPERATURE MAX7 toc 7 OUTPUT VOLTAGE SWING (V OL ) vs. TEMPERATURE MAX7 toc OUTPUT VOLTAGE (V).1.1. V DD - V OH V OL OUTPUT LOAD CURRENT (ma) VDD - VOH (mv) 3 1 R L = 1kΩ R L = 1kΩ TEMPERATURE ( C) VOL (mv) 3 1 R L = 1kΩ TEMPERATURE ( C) R L = 1kΩ AV (db) LARGE-SIGNAL VOLTAGE GAIN vs. OUTPUT VOLTAGE SWING R L = kω R L = kω R L = kω MAX7 toc7 AV (db) LARGE-SIGNAL VOLTAGE GAIN vs. OUTPUT VOLTAGE SWING R L = kω R L = kω R L = kω MAX7 toc8 AV (db) LARGE-SIGNAL VOLTAGE GAIN vs. OUTPUT VOLTAGE SWING R L = kω R L = kω R L = kω MAX7 toc V DD = 3V R L REFERENCED TO GND V DD = 3V R L REFERENCED TO V DD V DD = V R L REFERENCED TO GND 1 1 SWING FROM EITHER SUPPLY (mv) 1 1 SWING FROM EITHER SUPPLY (mv) 1 1 SWING FROM EITHER SUPPLY (mv) AV (db) LARGE-SIGNAL VOLTAGE GAIN vs. OUTPUT VOLTAGE SWING R L = kω R L = kω R L = kω V DD = V R L REFERENCED TO V DD 1 1 SWING FROM EITHER SUPPLY (mv) MAX7 toc1 AVOL (db) LARGE-SIGNAL VOLTAGE GAIN vs. TEMPERATURE R L = 1kΩ = 1mV TO.7V TEMPERATURE ( C) R L = 1kΩ MAX7 toc11 SUPPLY CURRENT (ma) PER AMPLIFIER SUPPLY CURRENT vs. TEMPERATURE TEMPERATURE ( C) MAX7 toc1 Maxim Integrated

6 Typical Operating Characteristics (continued) (V DD = +V, V SS = V, V CM = V, = V DD /, R L tied to V DD /, input noise floor of test equipment =1nV/ Hz for all distortion measurements, T A = + C, unless otherwise noted.) SUPPLY CURRENT (ma) PER AMPLIFIER SUPPLY CURRENT vs. SUPPLY VOLTAGE MAX7 toc13 SUPPLY CURRENT (ma) SUPPLY CURRENT vs.output VOLTAGE V DD = 3V V DD = V MAX7 toc1 INPUT OFFSET VOLTAGE (µv) INPUT OFFSET VOLTAGE vs. SUPPLY VOLTAGE MAX7 toc SUPPLY VOLTAGE (V) 1 3 OUTPUT VOLTAGE (V) SUPPLY VOLTAGE (V) GAIN (db) MAX7 MAX78 GAIN AND PHASE vs. FREQUENCY MAX7 toc1 V DD = 3V OR V 18 R L = kω 1 GAIN C L = pf 18 A V = +1V/V PHASE k 1k 1k 1M 1M 1M INPUT FREQUENCY (Hz) PHASE (degrees) GAIN (db) 3 1 GAIN AND PHASE vs. FREQUENCY GAIN -1 V DD = 3V OR V -7 - R L = kω PHASE C L = pf A V = +1V/V k 1k 1k 1M 1M 1M INPUT FREQUENCY (Hz) MAX7 toc PHASE (degrees) PSRR (db) MAX7 MAX78 POWER-SUPPLY REJECTION RATIO vs. FREQUENCY -1 V DD = 3V OR V , FREQUENCY (khz) MAX7 toc18 OUTPUT IMPEDANCE (Ω) OUTPUT IMPEDANCE vs. FREQUENCY A V = k 1k FREQUENCY (Hz) A V = +1 MAX7 toc19 Maxim Integrated

7 Typical Operating Characteristics (continued) (V DD = +V, V SS = V, V CM = V, = V DD /, R L tied to V DD /, input noise floor of test equipment =1nV/ Hz for all distortion measurements, T A = + C, unless otherwise noted.) VIN EQUIVALENT INPUT NOISE VOLTAGE (nv Hz) 1 1 INPUT VOLTAGE-NOISE DENSITY vs. FREQUENCY 1 1 1k 1k 1k FREQUENCY (Hz) MAX7 toc nv/div.1hz TO 1Hz P-P NOISE V DD = 3V OR V V P-P NOISE = nv P-P 1s/div MAX7 toc1 THD + N (%) MAX7 TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT VOLTAGE SWING 1 A V = +1 R L = 1kΩ f O = khz, FILTER BW = 8kHz f O = 3kHz, FILTER BW = 3kHz OUTPUT VOLTAGE (V P-P ) MAX7 toc THD + N (%) TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT VOLTAGE SWING 1 A V = + R L = 1kΩ V DD = 3V, f O = 3kHz FILTER BW = 3kHz V DD = +3V, f O = khz FILTER BW = 8kHz OUTPUT VOLTAGE (V P-P ) MAX7 toc3 THD + N (%).1.1 TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY A V = +1, V DD = 3V FILTER BW = khz A V = +1, V DD = V R L = 1kΩ TO GND R1 =.kω, R = 3kΩ = V P-P.1 k 1k 1k k FREQUENCY (Hz) MAX7 toc THD + N (%) MAX7 MAX78 TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY.1 FILTER BW = 8kHz = V P-P A V = +1 R L = 1kΩ R L TO V DD / R L TO GND.1 R L TO V DD k 1k 1k k FREQUENCY (Hz) MAX7 toc TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY 1.1 FILTER BW = 8kHz R L = 1kΩ TO GND R 1 =.3kΩ, R = 1kΩ =.7V P-P MAX7 toc MAX7 MAX78 LARGE-SIGNAL PULSE RESPONSE MAX7 toc7.v MAX7 MAX78 SMALL-SIGNAL PULSE RESPONSE MAX7 toc8.v THD + N (%).1 mv/div.1 A V = +, V DD = 3V.V.V.1 A V = +, V DD = V k 1k 1k k FREQUENCY (Hz) 1µs/div V DD = 3V, R L = 1kΩ, C L = 1pF V IN = V µs/div V DD = 3V, R L = 1kΩ, C L = 1pF V IN = 1mV PULSE Maxim Integrated 7

8 Typical Operating Characteristics (continued) (V DD = +V, V SS = V, V CM = V, = V DD /, R L tied to V DD /, input noise floor of test equipment =1nV/ Hz for all distortion measurements, T A = + C, unless otherwise noted.) LARGE-SIGNAL PULSE RESPONSE MAX7 toc9 mv/div SMALL-SIGNAL PULSE RESPONSE MAX7 toc3 1.V mv/div 1.V CROSSTALK (db) MAX77/MAX78/MAX89 CROSSTALK vs. FREQUENCY MAX7 toc31-8 1µs/div V DD = 3V, R L = 1kΩ, C L = pf V IN = mv PULSE, A V = +V/V 1µs/div V DD = 3V, R L = 1kΩ, C L = pf V IN = mv PULSE, A V = +V/V k 1k 1M 1M 1M FREQUENCY (Hz) Pin Description MAX7/ MAX88 MAX7/ MAX88 PIN MAX7 MAX77/ MAX89 MAX78 SOT3/TDFN SO/µMAX SOT3/TDFN SO/µMAX SO/TSSOP 1 1 1, 7 1, 7, 8, 1 NAME OUT, OUTA, OUTB, OUTC, OUTD FUNCTION Amplifier Output 11 V SS to ground for single-supply Negative Supply. Connect operation , 3,, 1, 1 IN+, INA+, INB+, INC+, IND+ Noninverting Amplifier Input,,, 9, 13 IN-, INA-, INB-, INC-, IND- Inverting Amplifier Input 7 8 V DD Positive Supply 8 SHDN 1, N.C. EP EP EP Shutdown Input. Connect to V DD for normal operation (amplifier(s) enabled). No Connection. Not internally connected. Exposed Paddle (TDFN Only). Connect to V SS. Maxim Integrated 8

9 Detailed Description The MAX7 MAX78/ singlesupply operational amplifiers feature ultra-low noise and distortion. Their low distortion and low noise make them ideal for use as preamplifiers in wide dynamic-range applications, such as 1-bit analog-to-digital converters (see Typical Operating Circuit). Their high-input impedance and low noise are also useful for signal conditioning of high-impedance sources, such as piezoelectric transducers. These devices have true rail-to-rail output operation, drive loads as low as 1kΩ while maintaining DC accuracy, and can drive capacitive loads up to pf without oscillation. The input common-mode voltage range extends from (V DD - 1.V) to mv below the negative rail. The pushpull output stage maintains excellent DC characteristics, while delivering up to ±ma of current. The MAX7 MAX78 are unity-gain stable, while the have a higher slew rate and are stable for gains V/V. The MAX7/MAX88 feature a low-power shutdown mode, which reduces the supply current to.1µa and disables the outputs. Low Distortion Many factors can affect the noise and distortion that the device contributes to the input signal. The following guidelines offer valuable information on the impact of design choices on Total Harmonic Distortion (THD). Choosing proper feedback and gain resistor values for a particular application can be a very important factor in reducing THD. In general, the smaller the closed-loop gain, the smaller the THD generated, especially when driving heavy resistive loads. The THD of the part normally increases at approximately db per decade, as a function of frequency. Operating the device near or above the full-power bandwidth significantly degrades distortion. Referencing the load to either supply also improves the part s distortion performance, because only one of the MOSFETs of the push-pull output stage drives the output. Referencing the load to midsupply increases the part s distortion for a given load and feedback setting. (See the Total Harmonic Distortion vs. Frequency graph in the Typical Operating Characteristics.) For gains V/V, the decompensated devices MAX88/ MAX89 deliver the best distortion performance, since they have a higher slew rate and provide a higher amount of loop gain for a given closed-loop gain setting. Capacitive loads below 1pF do not significantly affect distortion results. Distortion performance is relatively constant over supply voltages. Figure 1. Adding Feed-Forward Compensation 1mV V R G V IN A V = + R F = R G = 1kΩ Figure a. Pulse Response with No Feed-Forward Compensation A V = + R F = R G = 1kΩ µs/div µs/div V IN 1mV/div 1mV/div V IN 1mV/div 1mV/div Figure b. Pulse Response with 1pF Feed-Forward Compensation R F C Z Maxim Integrated 9

10 Low Noise The amplifier s input-referred noise-voltage density is dominated by flicker noise at lower frequencies, and by thermal noise at higher frequencies. Because the thermal noise contribution is affected by the parallel combination of the feedback resistive network (R F R G, Figure 1), these resistors should be reduced in cases where the system bandwidth is large and thermal noise is dominant. This noise contribution factor decreases, however, with increasing gain settings. For example, the input noise-voltage density of the circuit with R F = 1kΩ, R G = 11kΩ (A V = +V/V) is e n = 1nV/ Hz, e n can be reduced to nv/ Hz by choosing R F = 1kΩ, R G = 1.1kΩ (A V = +V/V), at the expense of greater current consumption and potentially higher distortion. For a gain of 1V/V with R F = 1kΩ, R G = 1.1kΩ, the e n is still a low nv/ Hz. Using a Feed-Forward Compensation Capacitor, CZ The amplifier s input capacitance is 1pF. If the resistance seen by the inverting input is large (feedback network), this can introduce a pole within the amplifier s bandwidth resulting in reduced phase margin. Compensate the reduced phase margin by introducing a feed-forward capacitor (C Z ) between the inverting input and the output (Figure 1). This effectively cancels the pole from the inverting input of the amplifier. Choose the value of C Z as follows: C Z = 1 x (R F / R G ) [pf] In the unity-gain stable MAX7 MAX78, the use of a proper C Z is most important for A V = +V/V, and A V = -1V/V. In the decompensated, C Z is most important for A V = +1V/V. Figures a and b show transient response both with and without C Z. Using a slightly smaller C Z than suggested by the formula above achieves a higher bandwidth at the expense of reduced phase and gain margin. As a general guideline, consider using C Z for cases where R G R F is greater than kω (MAX7 MAX78) or greater than kω (). Applications Information The MAX7 MAX78/ combine good driving capability with ground-sensing input and rail-to-rail output operation. With their low distortion and low noise, they are ideal for use in ADC buffers, medical instrumentation systems and other noise-sensitive applications. V Figure 3. Overdriven Input Showing No Phase Reversal V V A V = +1 V DD = +V R L = 1kΩ µs/div ms/div Figure. Rail-to-Rail Output Operation V IN V/div V/div 1V/div Ground-Sensing and Rail-to-Rail Outputs The common-mode input range of these devices extends below ground, and offers excellent common-mode rejection. These devices are guaranteed not to undergo phase reversal when the input is overdriven (Figure 3). Figure showcases the true rail-to-rail output operation of the amplifier, configured with A V = V/V. The output swings to within 8mV of the supplies with a 1kΩ load, making the devices ideal in low-supply voltage applications. Power Supplies and Layout The MAX7 MAX78/ operate from a single +.7V to +.V power supply or from dual supplies of ±1.3V to ±.7V. For single-supply operation, bypass the power supply with a.1µf ceramic Maxim Integrated 1

11 Typical Application Circuit +V +.V +V SERIAL INTERFACE CS SCLK DIN V DD U1 MAX1ESA DGND REF AGND OUT 3 7 U MAX7AUA to +.V OUTPUT 8 SHDN Typical Operating Circuit 7pF V.1µF 3.9kΩ 7.87kΩ pf 1.kΩ 3 8 1/ MAX77 1.kΩ kΩ 13.7kΩ pf 1.kΩ pf 1/ MAX77 1.kΩ 7 7.1kΩ pf capacitor placed close to the V DD pin. If operating from dual supplies, bypass each supply to ground. Good layout improves performance by decreasing the amount of stray capacitance and noise at the op amp s inputs and output. To decrease stray capacitance, minimize PC board trace lengths and resistor leads, and place external components close to the op amp s pins. Typical Application Circuit The Typical Application Circuit shows the single MAX7 configured as an output buffer for the MAX1 1-bit DAC. Because the MAX1 has an unbuffered voltage output, the input bias current of the op amp used must be less than na to maintain 1-bit accuracy. The MAX7 has an input bias current of only 1pA (max), virtually eliminating this as a source of error. In addition, the MAX7 has excellent openloop gain and common-mode rejection, making this an excellent output buffer amplifier. DC-Accurate Lowpass Filter The MAX7 MAX78/ offer a unique combination of low noise, wide bandwidth, and high gain, making them an excellent choice for active filters up to 1MHz. The Typical Operating Circuit shows the dual MAX77 configured as a th order Chebyschev filter with a cutoff frequency of 1kHz. The circuit is implemented in the Sallen-Key topology, making this a DC-accurate filter. Maxim Integrated 11

12 Pin Configurations TOP VIEW N.C. + 8 SHDN TOP VIEW OUTA V DD INA+ 3 MAX7 MAX88 7 V DD OUT INB- INA- INA+ 3 MAX77 MAX89 7 OUTB INA- V SS N.C. V SS INB+ SO/MAX SO/MAX TOP VIEW OUTA OUTD TOP VIEW OUT + 1 V DD TOP VIEW VDD SHDN IN- IND- IND+ V SS INC+ INC- INA- INA+ V DD INB+ INB- 3 MAX V SS IN+ MAX7 MAX88 3 SHDN IN- MAX7 MAX88 EP OUTB 7 8 OUTC SOT SO/TSSOP OUT VSS TDFN IN+ TOP VIEW + OUT 1 V DD TOP VIEW VDD N.C. IN- V SS MAX7 N.C. MAX7 IN+ 3 IN- EP SOT OUT VSS TDFN IN+ Maxim Integrated 1

13 Ordering Information PART TEMP RANGE PIN- PACKAGE TOP MARK MAX7AUT+T - C to +1 C SOT3 AAZV MAX7AUA+ - C to +1 C 8 µmax MAX7ASA+ - C to +1 C 8 SO MAX7ATT+T - C to +1 C TDFN-EP* +ADD MAX7AUT/V+T - C to +1 C SOT3 +ACQQ MAX7AUT+T - C to +1 C SOT3 AAZX MAX7ATT+T - C to +1 C TDFN-EP* +ADF MAX77AUA+ - C to +1 C 8 µmax MAX77AUA+ - C to +1 C 8 µmax MAX77AUA/V+T** - C to +1 C 8 µmax MAX77ASA+ - C to +1 C 8 SO MAX78AUD+ - C to +1 C 1 TSSOP MAX78AUD/V+ - C to +1 C 1 TSSOP MAX78ASD+ - C to +1 C 1 SO MAX88AUT+T - C to +1 C SOT3 AAZW MAX88AUA+ - C to +1 C 8 µmax MAX88ASA+ - C to +1 C 8 SO MAX88ATT+T - C to +1 C TDFN-EP* +ADE MAX89AUA+ - C to +1 C 8 µmax MAX89AUA/V+T - C to +1 C 8 µmax MAX89ASA+ - C to +1 C 8 SO Chip Information PROCESS: BiCMOS Selector Guide PART GAIN BW (MHz) STABLE GAIN (V/V) NO. OF AMPS SHDN MAX Yes MAX MAX MAX MAX88 1 Yes MAX89 +Denotes a lead(pb)-free/rohs-compliant package. *EP = Exposed pad (connect to V SS ). **Future product Contact Maxim for availability. /V denotes an automotive qualified part. T = Tape and reel. Maxim Integrated 13

14 Package Information For the latest package outline information and land patterns (footprints), go to Note that a +, #, or - in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. SOT3 UF µmax U µmax U TSSOP U SO S SO S TDFN-EP T Maxim Integrated 1

15 Revision History REVISION NUMBER REVISION DATE DESCRIPTION PAGES CHANGED 1/9 Added lead-free designations and an automotive part to the Ordering Information and added input current spec in Absolute Maximum Ratings section 7/1 Added /V designation to the MAX7 product and soldering temperature 1, /1 Added /V designation for MAX /18 Added AEC statement to Features section 1 8 7/18 Updated Ordering Information table 1 1,, /18 Updated Absolute Maximum Rating and Package Information, 1 For pricing, delivery, and ordering information, please visit Maxim Integrated s online storefront at Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. 18 Maxim Integrated Products, Inc. 1