MAX4267EUA -40 C to +85 C 8 µmax. MAX4268EEE -40 C to +85 C 16 QSOP. MAX4270EEE -40 C to +85 C 16 QSOP

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1 9; Rev ; 8/ Ultra-Low-Distortion, +V, MHz Op Amps with Disable General Description The MAX6 MAX7 ultra-low distortion, voltage-feedback op amps are capable of driving a Ω load while maintaining ultra-low distortion over a wide bandwidth. They offer superior spurious-free dynamic range (SFDR) performance: -9dBc at MHz and 9dBc at MHz (MAX69). Additionally, input voltage noise density is 8nV/ Hz while operating from a single +.V to +8.V supply or from dual ±.V to ±.V supplies. These features make the MAX6 MAX7 ideal for use in high-performance communications and signal-processing applications that require low distortion and wide bandwidth. The MAX6 single and MAX68 dual amplifiers are unity-gain stable. The MAX66 single and MAX69 dual amplifiers are compensated for a minimum stable gain of +V/V, while the MAX67 single and MAX7 dual amplifiers are compensated for a minimum stable gain of +V/V. For additional power savings, these amplifiers feature a low-power disable mode that reduces supply current and places the outputs in a high-impedance state. The MAX6/MAX66/MAX67 are available in a spacesaving 8-pin µmax package, and the MAX68/ MAX69/MAX7 are available in a 6-pin QSOP package. Base-Station Amplifiers IF Amplifiers High-Frequency ADC Drivers High-Speed DAC Buffers RF Telecom Applications High-Frequency Signal Processing Applications Features Operates from +.V to +8.V Superior SFDR with Ω Load -9dBc (f C = MHz) 9dBc (f C = MHz) dbm IP (f C = MHz) 8nV/ Hz Voltage Noise Density MHz.dB Gain Flatness (MAX68) 9V/µs Slew Rate ±ma Output Driving Capability Disable Mode Places Outputs in High-Impedance State Ordering Information PART TEMP. RANGE PIN-PACKAGE MAX6EUA - C to +8 C 8 µmax MAX6ESA - C to +8 C 8 SO MAX66EUA - C to +8 C 8 µmax MAX66ESA - C to +8 C 8 SO MAX67EUA - C to +8 C 8 µmax MAX67ESA - C to +8 C 8 SO MAX68EEE - C to +8 C 6 QSOP MAX68ESD - C to +8 C SO MAX69EEE - C to +8 C 6 QSOP MAX69ESD - C to +8 C SO MAX7EEE - C to +8 C 6 QSOP MAX7ESD - C to +8 C SO µmax is a registered trademark of Maxim Integrated Products, Inc. MAX6 MAX7 Pin Configurations appear at end of data sheet. PART NO. OF MIN GAIN -db OP AMPS (V/V) BANDWIDTH (MHz) MAX6 MAX66 MAX67 MAX68 MAX69 MAX7 GBP (MHz) 7 7 Selector Guide FULL-POWER BANDWIDTH (MHz) 7 7 Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at , or visit Maxim s website at

2 MHz Op Amps with Disable MAX6 MAX7 ABSOLUTE MAXIMUM RATINGS Supply Voltage (V CC to V EE )...+8.V Voltage on Any Other Pin...(V EE -.V) to (V CC +.V) Short-Circuit Duration (V OUT to V CC or V EE )...Continuous Continuous Power Dissipation (T A = +7 C) 8-Pin µmax (derate.mw/ C above +7 C)...mW 6-Pin QSOP (derate 8.mW/ C above +7 C)...667mW 8-Pin SO (derate.9mw/ C above +7 C)...7mW -Pin SO (derate 8.mW/ C above +7 C)...667mW 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 Operating Temperature Range...- C to +8 C Storage Temperature Range...-6 C to + C Junction Temperature...+ C Lead Temperature (soldering, s)...+ C (V CC = +V, V EE =, R L = Ω to V CC /, V CM = V CC /, T A = T MIN to T MAX, unless otherwise noted. Typical values are at T A = + C.) PARAMETER Operating Supply Voltage Range Common-Mode Input Voltage Input Offset Voltage Input Offset Voltage Drift SYMBOL V CC V CM V OS TCV OS CONDITIONS Inferred from PSRR test Inferred from CMRR test MIN TYP MAX. 8. V EE +.6 V CC UNITS V V mv µv/ C Input Offset Voltage Channel Matching MAX68/MAX69/MAX7 mv Input Bias Current I B. µa Input Offset Current I OS. 6 µa Common-Mode Input Resistance R INCM Either input (V EE +.6V) V CM (V CC -.6V) MΩ Differential Input Resistance R INDIFF -mv V IN mv kω Common-Mode Rejection Ratio CMRR (V EE +.6V) V CM (V CC -.6V), no load 6 8 db Power-Supply Rejection Ratio PSRR V CC =.V to 8.V 6 8 db Open-Loop Voltage Gain A OL.7V V OUT.V 6 9 db Output Voltage Swing V OUT V CC - V OH, V OL - V EE.. V Output Current Drive I OUT R L = Ω ± ± ma Output Short-Circuit Current I SC Sinking or sourcing to V CC or V EE ma Closed-Loop Output Resistance R OUT. Ω Power-Up Time t PWRUP V OUT = V step,.% settling time µs Quiescent Supply Current (per amplifier) I S Normal mode, DISABLE_ = V CC or floating Disable mode, DISABLE_ = V EE 8.6 ma ma Disable Output Leakage Current DISABLE_ = V EE, V EE V OUT V CC.. µa DISABLE_ Logic Low V CC -. V DISABLE_ Logic High V CC -. V DISABLE_ Logic Input Low Current DISABLE_ = V EE µa DISABLE_ Logic Input High Current DISABLE_ = V CC µa

3 MHz Op Amps with Disable AC ELECTRICAL CHARACTERISTICS (V CC = +V, V EE =, R L = Ω to V CC /, V CM = V CC /, MAX6/MAX68 A V = +V/V, MAX66/MAX69 A V = +V/V, MAX67/MAX7 A V = +V/V, T A = T MIN to T MAX, unless otherwise noted. Typical values are at T A = + C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Small-Signal -db Bandwidth BW -db V OU T = m Vp - p Full-Power Bandwidth FPBW V OUT = Vp-p.dB Gain Flatness BW.dB V OU T = m Vp - p MAX6 MAX66 MAX67 MAX68 MAX69 MAX7 MAX6 7 MAX66 MAX67 MAX68 7 MAX69 MAX7 MAX6 8 MAX66 MAX67 MAX68 MAX69 MAX7 All-Hostile Crosstalk f = MHz 8 db Slew Rate SR V OUT = +V step 9 V/µs Rise/Fall Times t R, t F V OUT = +V step ns Settling Time (.%) t S,. V OUT = +V step ns Spurious-Free Dynamic Range SFDR V OUT = Vp-p (MAX6/ MAX66/ MAX67) V OUT = Vp-p (MAX68) f C = MHz 8 f C = MHz 8 f C = MHz 87 f C = MHz 8 f C = 6MHz f C = MHz 7 f C = MHz 8 f C = MHz 8 f C = MHz 8 f C = MHz 79 f C = 6MHz 68 f C = MHz 6 MHz MHz MHz dbc MAX6 MAX7

4 MHz Op Amps with Disable MAX6 MAX7 AC ELECTRICAL CHARACTERISTICS (continued) (V CC = +V, V EE =, R L = Ω to V CC /, V CM = V CC /, MAX6/MAX68 A V = +V/V, MAX66/MAX69 A V = +V/V, MAX67/MAX7 A V = +V/V, T A = T MIN to T MAX, unless otherwise noted. Typical values are at T A = + C.) Spurious-Free Dynamic Range Second Harmonic Distortion PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS SFDR V OUT = Vp-p (MAX69) V OUT = Vp-p (MAX7) V OUT = Vp-p (MAX6/ MAX66/ MAX67) V OUT = Vp-p (MAX68) V OUT = Vp-p (MAX69) V OUT = Vp-p (MAX7) f C = MHz 88 f C = MHz 9 f C = MHz 88 f C = MHz 79 f C = 6MHz 68 f C = MHz 9 f C = MHz 86 f C = MHz 8 f C = MHz 7 f C = MHz 68 f C = 6MHz 6 f C = MHz 6 f C = MHz 8 f C = MHz 8 f C = MHz 87 f C = MHz 8 f C = 6MHz f C = MHz 7 f C = MHz 8 f C = MHz 8 f C = MHz 8 f C = MHz 79 f C = 6MHz 68 f C = MHz 6 f C = MHz 88 f C = MHz 9 f C = MHz 88 f C = MHz 79 f C = 6MHz 68 f C = MHz 9 f C = MHz 86 f C = MHz 8 f C = MHz 7 f C = MHz 68 f C = 6MHz 6 f C = MHz 6 dbc dbc

5 MHz Op Amps with Disable AC ELECTRICAL CHARACTERISTICS (continued) (V CC = +V, V EE =, R L = Ω to V CC /, V CM = V CC /, MAX6/MAX68 A V = +V/V, MAX66/MAX69 A V = +V/V, MAX67/MAX7 A V = +V/V, T A = T MIN to T MAX, unless otherwise noted. Typical values are at T A = + C.) Third Harmonic Distortion PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Two-Tone, Third-Order Intercept Distortion IP V OUT = Vp-p (MAX6/ MAX66/ MAX67) V OUT = Vp-p (MAX68) V OUT = Vp-p (MAX69) V OUT = Vp-p (MAX7) f C = MHz 98 f C = MHz 96 f C = MHz 9 f C = MHz 8 f C = 6MHz 7 f C = MHz 6 f C = MHz 9 f C = MHz 9 f C = MHz 9 f C = MHz 86 f C = 6MHz 7 f C = MHz 6 f C = MHz 88 f C = MHz 9 f C = MHz 88 f C = MHz 79 f C = 6MHz 68 f C = MHz 9 f C = MHz 96 f C = MHz 97 f C = MHz 9 f C = MHz 8 f C = 6MHz 7 f C = MHz 69 V OUT = Vp-p, MAX6/MAX68 f CA = MHz, MAX66/MAX69 f CB =.MHz MAX67/MAX7 dbc dbm MAX6 MAX7

6 MHz Op Amps with Disable MAX6 MAX7 AC ELECTRICAL CHARACTERISTICS (continued) (V CC = +V, V EE =, R L = Ω to V CC /, V CM = V CC /, MAX6/MAX68 A V = +V/V, MAX66/MAX69 A V = +V/V, MAX67/MAX7 A V = +V/V, T A = T MIN to T MAX, unless otherwise noted. Typical values are at T A = + C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Input -db Compression Point f C = MHz dbm Differential Gain D G NTSC, f =.8MHz, R L = Ω to V CC /. % Differential Phase D P NTSC, f =.8MHz, R L = Ω to V CC /. degrees Input Capacitance C IN pf Output Impedance R OUT f = MHz Ω Disabled Output Capacitance DISABLE_ = V EE pf Enable Time t EN V IN = +V ns Disable Time t DIS V IN = +V 7 µs MAX6/MAX68 No sustained MAX66/MAX69 pf Capacitive Load Stability oscillation MAX67/MAX7 Input Voltage Noise Density e n f = khz 8 nv/ Hz Input Current Noise Density i n f = khz pa/ Hz Typical Operating Characteristics (V CC = +V, V EE =, DISABLE_ = +V, R L = Ω to V CC /, MAX6/MAX68 A V = +V/V, MAX66/MAX69 A V = +V/V, MAX67/MAX7 A V = +V/V, T A = + C, unless otherwise noted.) MAX68/MAX69/MAX7 SMALL-SIGNAL GAIN vs. FREQUENCY V OUT = mvp-p MAX69 MAX7 MAX68 MAX6/ MAX68/MAX69/MAX7 LARGE-SIGNAL GAIN vs. FREQUENCY V OUT = Vp-p MAX69 MAX7 MAX68 MAX6/ MAX68/MAX69/MAX7 GAIN FLATNESS vs. FREQUENCY MAX7 MAX68 MAX69 MAX6/ M M M M G -6.M M M M G -.6.M M M M G 6

7 MHz Op Amps with Disable Typical Operating Characteristics (continued) (V CC = +V, V EE =, DISABLE_ = +V, R L = Ω to V CC /, MAX6/MAX68 A V = +V/V, MAX66/MAX69 A V = +V/V, MAX67/MAX7 A V = +V/V, T A =+ C, unless otherwise noted.) MAX6/MAX66/MAX67 SMALL-SIGNAL GAIN vs. FREQUENCY MAX66-6.M M M M G MAX67 MAX6 MAX6/ MAX6/MAX66/MAX67 LARGE-SIGNAL GAIN vs. FREQUENCY V OUT = Vp-p MAX66 MAX67-6.M M M M G MAX6 MAX6/ MAX6/MAX66/MAX67 GAIN FLATNESS vs. FREQUENCY MAX66 MAX M M M M G MAX6 MAX6/7-6 MAX6 MAX MAX6/MAX66/MAX67 DISTORTION vs. FREQUENCY V OUT = Vp-p MAX6/ MAX68 DISTORTION vs. FREQUENCY V OUT = Vp-p MAX6/ MAX69 DISTORTION vs. FREQUENCY V OUT = Vp-p MAX6/7-9 DISTORTION (db) ND HARMONIC ND HARMONIC RD HARMONIC ND HARMONIC -9 RD HARMONIC -9 RD HARMONIC FREQUENCY (MHz) -. FREQUENCY (MHz) -. FREQUENCY (MHz) MAX7 DISTORTION vs. FREQUENCY V OUT = Vp-p MAX6/ MAX6/MAX66/MAX67 DISTORTION vs. LOAD RESISTANCE f O = MHz V OUT = V p-p MAX6/ MAX68 DISTORTION vs. LOAD RESISTANCE f O = MHz V OUT = Vp-p MAX6/ ND HARMONIC -8 ND HARMONIC -8 ND HARMONIC -9 RD HARMONIC -9 RD HARMONIC -9 RD HARMONIC -. FREQUENCY (MHz) - 6 R LOAD (Ω) - 6 R LOAD (Ω) 7

8 MHz Op Amps with Disable MAX6 MAX7 Typical Operating Characteristics (continued) (V CC = +V, V EE =, DISABLE_ = +V, R L = Ω to V CC /, MAX6/MAX68 A V = +V/V, MAX66/MAX69 A V = +V/V, MAX67/MAX7 A V = +V/V, T A =+ C, unless otherwise noted.) MAX69 DISTORTION vs. LOAD RESISTANCE f O = MHz V OUT = Vp-p 6 R LOAD (Ω) ND HARMONIC RD HARMONIC MAX6/ MAX7 DISTORTION vs. LOAD RESISTANCE f O = MHz V OUT = Vp-p ND HARMONIC RD HARMONIC 6 R LOAD (Ω) MAX6/ MAX6/MAX66/MAX67 DISTORTION vs. VOLTAGE SWING f O = MHz..... VOLTAGE SWING (V) ND HARMONIC RD HARMONIC MAX6/ MAX68 DISTORTION vs. VOLTAGE SWING f O = MHz MAX6/ MAX69 DISTORTION vs. VOLTAGE SWING f O = MHz MAX6/ MAX7 DISTORTION vs. VOLTAGE SWING f O = MHz MAX6/ ND HARMONIC ND HARMONIC RD HARMONIC ND HARMONIC -9 - RD HARMONIC..... VOLTAGE SWING (Vp-p) VOLTAGE SWING (Vp-p) -9 - RD HARMONIC..... VOLTAGE SWING (Vp-p) THD + NOISE (%).. TOTAL HARMONIC DISTORTION PLUS NOISE vs. FREQUENCY V OUT = Vp-p MAX67/MAX7 MAX66/MAX69.. FREQUENCY (MHz) MAX6/MAX68 MAX6/7-9 SFDR (dbc) SPURIOUS-FREE DYNAMIC RANGE vs. FREQUENCY V OUT = Vp-p MAX69 MAX7-9 MAX68 -. FREQUENCY (MHz) MAX6/7- INTERCEPT (dbm) 6 TWO-TONE THIRD-ORDER INTERCEPT vs. FREQUENCY MAX67/MAX7 MAX66/MAX69 MAX6/MAX68. FREQUENCY (MHz) MAX6/7-8

9 MHz Op Amps with Disable Typical Operating Characteristics (continued) (V CC = +V, V EE =, DISABLE_ = +V, R L = Ω to V CC /, MAX6/MAX68 A V = +V/V, MAX66/MAX69 A V = +V/V, MAX67/MAX7 A V = +V/V, T A =+ C, unless otherwise noted.) VOLTAGE NOISE (nv/ Hz) VOLTAGE NOISE vs. FREQUENCY k k k M M MAX6/7- OUTPUT IMPEDANCE (Ω). OUTPUT IMPEDANCE vs. FREQUENCY..M M M M MAX6/7- G CROSSTALK (db) MAX68/MAX69/MAX7 CROSSTALK vs. FREQUENCY -.M M M M MAX6/7- G MAX6 MAX7 DIFF PHASE ( ) DIFF GAIN (%) PSRR (db) R L = Ω MAX6/MAX68 DIFFERENTIAL GAIN AND PHASE IRE IRE POWER-SUPPLY REJECTION RATIO vs. FREQUENCY -.M M M M G MAX6/7 MAX6/7-8 DIFF PHASE ( ) DIFF GAIN (%) CMRR (db) R L = Ω MAX66/MAX69 DIFFERENTIAL GAIN AND PHASE IRE IRE COMMON-MODE REJECTION RATIO vs. FREQUENCY k k M M M G MAX6/7-6 MAX6/7-9 DIFF PHASE ( ) DIFF GAIN (%) OUTPUT VOLTAGE SWING (V) R L = Ω MAX67/MAX7 DIFFERENTIAL GAIN AND PHASE IRE IRE OUTPUT VOLTAGE SWING vs. RESISTIVE LOAD RESISTANCE V OH V OL 6 8 R LOAD (Ω) MAX6/7-7 MAX6/7-9

10 MHz Op Amps with Disable MAX6 MAX7 Typical Operating Characteristics (continued) (V CC = +V, V EE =, DISABLE_ = +V, R L = Ω to V CC /, MAX6/MAX68 A V = +V/V, MAX66/MAX69 A V = +V/V, MAX67/MAX7 A V = +V/V, T A =+ C, unless otherwise noted.) VCC.V/div OUTPUT mv/div POWER-UP/POWER-DOWN RESPONSE µs/div MAX6/7- V V INPUT TO DISABLE_ OUTPUT mv/div DISABLE/ENABLE RESPONSE ns/div MAX6/7- V V ENABLE DISABLE INPUT OFFSET VOLTAGE (mv) INPUT OFFSET VOLTAGE vs. SUPPLY VOLTAGE SUPPLY VOLTAGE (V) MAX6/7- INPUT BIAS CURRENT (µa) INPUT BIAS CURRENT vs. SUPPLY VOLTAGE MAX6/7- SUPPLY CURRENT (ma) SUPPLY CURRENT (PER AMPLIFIER) vs. SUPPLY VOLTAGE MAX6/7 INPUT OFFSET VOLTAGE (mv) INPUT OFFSET VOLTAGE vs. TEMPERATURE MAX6/ SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) TEMPERATURE ( C) INPUT BIAS CURRENT (µa) INPUT BIAS CURRENT vs. TEMPERATURE MAX6/7-7 INPUT OFFSET CURRENT (na) INPUT OFFSET CURRENT vs. TEMPERATURE MAX6/7-8 SUPPLY CURRENT (ma) SUPPLY CURRENT (PER AMPLIFIER) vs. TEMPERATURE MAX6/ TEMPERATURE ( C) TEMPERATURE ( C) TEMPERATURE ( C)

11 MHz Op Amps with Disable Typical Operating Characteristics (continued) (V CC = +V, V EE =, DISABLE_ = +V, R L = Ω to V CC /, MAX6/MAX68 A V = +V/V, MAX66/MAX69 A V = +V/V, MAX67/MAX7 A V = +V/V, T A =+ C, unless otherwise noted.) VOLTAGE SWING (V) VOLTAGE SWING vs. TEMPERATURE V OH V OL TEMPERATURE ( C) MAX6/7- INPUT mv/div OUTPUT mv/div MAX6/MAX68 SMALL-SIGNAL PULSE RESPONSE ns/div MAX6/7- INPUT mv/div OUTPUT mv/div MAX66/MAX69 SMALL-SIGNAL PULSE RESPONSE ns/div MAX6/7- MAX6 MAX7 MAX67/MAX7 SMALL-SIGNAL PULSE RESPONSE MAX6/MAX68 LARGE-SIGNAL PULSE RESPONSE MAX6/7- MAX6/7- INPUT mv/div INPUT mv/div OUTPUT mv/div OUTPUT mv/div ns/div ns/div MAX66/MAX69 LARGE-SIGNAL PULSE RESPONSE MAX67/MAX7 LARGE-SIGNAL PULSE RESPONSE MAX6/7 MAX6/7-6 INPUT mv/div INPUT mv/div OUTPUT mv/div OUTPUT mv/div ns/div ns/div

12 MHz Op Amps with Disable MAX6 MAX7 MAX6 MAX66 MAX67 8 µmax/so, PIN SO,, 9, 6, 7 MAX68 MAX69 MAX7 6 QSOP,,, 6, 7 NAME DISABLE DISABLEA, DISABLEB IN- INA-, INB- IN+ INA+, INB+ V EE FUNCTION Disable Input. Active low. Disable Input. Active low. Inverting Input Inverting Input Noninverting Input Noninverting Input Negative Power Supply Pin Description 6 OUT Amplifier Output, 8, OUTA, OUTB Amplifier Output 7, 8,, 6 V CC Positive Power Supply. Connect to a +.V to +8.V supply., 8, 9,, N.C. No Connection. Not internally connected. Detailed Description The MAX6 MAX7 family of operational amplifiers features ultra-low distortion and wide bandwidth. Their low distortion and low noise make them ideal for driving high-speed ADCs up to 6 bits in telecommunications applications and high-performance signal processing. These devices can drive a Ω load and deliver ma while maintaining DC accuracy and AC performance. The input common-mode voltage ranges from (V EE +.6V) to (V CC -.6V), while the output typically swings to within.v of the rails. Low Distortion The MAX6 MAX7 use proprietary bipolar technology to achieve minimum distortion in low-voltage systems. This feature is typically available only in dualsupply op amps. Several factors can affect the noise and distortion that a device contributes to the input signal. The following guidelines explain how various design choices impact the total harmonic distortion (THD): Choose the proper feedback-resistor and gain-resistor values for the application. In general, the smaller the closed-loop gain, the smaller the THD generated, especially when driving heavy resistive loads. Largevalue feedback resistors can significantly improve distortion. The MAX6 MAX7 s THD normally increases at approximately db per decade at frequencies above MHz; this is a lower rate than that of comparable dual-supply op amps. Operating the device near or above the full-power bandwidth significantly degrades distortion (see the Total Harmonic Distortion vs. Frequency graph in the Typical Operating Characteristics). The decompensated devices (MAX66/MAX67/ MAX69/MAX7) deliver the best distortion performance since they have a slightly higher slew rate and provide a higher amount of loop gain for a given closed-loop gain setting.

13 MHz Op Amps with Disable Choosing Resistor Values Unity-Gain Configurations The MAX6 and MAX68 are internally compensated for unity gain. When configured for unity gain, they require a small resistor (R F ) in series with the feedback path (Figure ). This resistor improves AC response by reducing the Q of the tank circuit, which is formed by parasitic feedback inductance and capacitance. Inverting and Noninverting Configurations The values of the gain-setting feedback and input resistors are important design considerations. Large resistor values will increase voltage noise and interact with the amplifier s input and PC board capacitance to generate undesirable poles and zeros, which can decrease bandwidth or cause oscillations. For example, a noninverting gain of +V/V (Figure ) using R F = R G = kω combined with pf of input capacitance and.pf of board capacitance will cause a feedback pole at 8MHz. If this pole is within the anticipated amplifier bandwidth, it will jeopardize stability. Reducing the kω resistors to Ω extends the pole frequency to.8ghz, but could limit output swing by adding Ω in parallel with the amplifier s load. Clearly, the selection of resistor values must be tailored to the specific application. Distortion Considerations The MAX6 MAX7 are ultra-low-distortion, highbandwidth op amps. Output distortion will degrade as the total load resistance seen by the amplifier decreases. To minimize distortion, keep the input and gain-setting resistor values relatively large. A Ω feedback resistor combined with an appropriate input resistor to set the gain will provide excellent AC performance without significantly increasing distortion. Driving Capacitive Loads The MAX6 MAX7 are not designed to drive highly reactive loads. Stability is maintained with loads up to pf with less than db peaking in the frequency response. To drive higher capacitive loads, place a small isolation resistor in series between the amplifier s output and the capacitive load (Figure ). This resistor improves the amplifier s phase margin by isolating the capacitor from the op amp s output. To ensure a load capacitance that limits peaking to less than db, select a resistance value from Figure. For example, if the capacitive load is pf, the corresponding isolation resistor is 6Ω (MAX66/MAX69). Figures and show the peaking that occurs in the frequency response with and without an isolation resistor. Coaxial cable and other transmission lines are easily driven when terminated at both ends with their characteristic impedance. When driving back-terminated transmission lines, the capacitive load of the transmission line is essentially eliminated. ADC Input Buffer Input buffer amplifiers can be a source of significant errors in high-speed ADC applications. The input buffer is usually required to rapidly charge and discharge the ADC s input, which is often capacitive (see Driving Capacitive Loads). In addition, since a high-speed ADC s input impedance often changes very rapidly during the conversion cycle, measurement accuracy must R G R F MAX6 MAX7 Noise Considerations 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, those resistor values 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 at the op amp input with a gain of +V/V using R F = kω and R G = kω is e n = 8nV/ Hz. The input noise can be reduced to 8nV/ Hz by choosing R F = kω, R G = Ω. V IN PART MAX6 MAX66 MAX67 R F (Ω) MAX6 MAX66 MAX67 R G (Ω) R S * *OPTIONAL, USED TO MINIMIZE PEAKING FOR C L > pf. Figure. Noninverting Configuration C L GAIN (V/V) R L

14 MHz Op Amps with Disable MAX6 MAX7 be maintained using an amplifier with very low output impedance at high frequencies. The combination of high speed, fast slew rate, low noise, and a low and stable distortion overload makes the MAX6 MAX7 ideally suited for use as buffer amplifiers in high-speed ADC applications. Low-Power Disable Mode The MAX6 MAX7 feature an active-low disable mode that can be used to save power and place the outputs in a high-impedance state. Drive DISABLE_ with logic levels, or connect DISABLE_ to V CC for normal operation. In the dual versions (MAX68/ MAX69/ MAX7), each individual op amp is disabled separately, allowing the devices to be used in a multiplex configuration. The supply current in low-power mode is reduced to.6ma per amplifier. Enable time is typically ns, and disable time is typically 7µs C L =.pf.m M M M G C L =.pf C L = 7.pF RISO (Ω) MAX6/MAX68 MAX66/MAX69 MAX67/MAX7 6 8 C LOAD (pf) Figure. MAX6 MAX7 Isolation Resistance vs. Capacitive Load C L = 7.pF C L =.pf.m M M M G C L =.pf Figure a. MAX68 Small-Signal Gain vs. Frequency Without Isolation Resistor Figure b. MAX69 Small-Signal Gain vs. Frequency Without Isolation Resistor C L = pf C L = pf C L = 7.pF C L = pf R ISO = Ω C L = pf R ISO = Ω C L = pf R ISO = 8Ω - -6.M M M M G.M M M M G Figure c. MAX7 Small-Signal Gain vs. Frequency Without Isolation Resistor Figure a. MAX68 Small-Signal Gain vs. Frequency With Isolation Resistor

15 MHz Op Amps with Disable C L = pf R ISO = Ω C L = pf R ISO = Ω.M M M M G C L = pf R ISO = 8Ω Figure b. MAX69 Small-Signal Gain vs. Frequency With Isolation Resistor Power Supplies, Bypassing, and Layout The MAX6 MAX7 operate from a single +.V to +8.V supply or in a dual-supply configuration. When operating with a single supply, connect the V EE pins directly to the ground plane. Bypass V CC to ground with ceramic chip capacitors. Due to the MAX6 MAX7s wide bandwidth, use a nf capacitor in parallel with a.µf to µf capacitor. If the device is located more than cm from the power supply, adding a larger bulk capacitor will improve performance. When operating with dual supplies, ensure that the total voltage across the device (V CC to V EE ) does not exceed +8V. Therefore, supplies of ±.V, ±.V, and asymmetrical supplies are possible. For example, operation with V CC = +V and V EE = -V provides sufficient voltage swing for the negative pulses found in video signals. When operating with dual supplies, the V CC pins and the V EE pins should be bypassed using the same guidelines stated in the paragraph above. C L = pf R ISO = Ω C L = pf R ISO =.9Ω C L = pf R ISO = 6Ω -6.M M M M G Figure c. MAX7 Small-Signal Gain vs. Frequency With Isolation Resistor Because the MAX6 MAX7 have high bandwidth, circuit layout becomes critical. A solid ground plane provides a low-inductance path for high-speed transient currents. Use multiple vias to the ground plane for each bypass capacitor. If V EE is connected to ground, use multiple vias here, too. Avoid sharing ground vias with other signals to reduce crosstalk between circuit sections. Avoid stray capacitance at the op amp s inverting inputs. Stray capacitance, in conjunction with the feedback resistance, forms an additional pole in the circuit s transfer function, with its associate phase shift. Minimizing the trace lengths connected to the inverting input helps minimize stray capacitance. Chip Information MAX6/66/67 TRANSISTOR COUNT: MAX68/69/7 TRANSISTOR COUNT: 8 PROCESS: Bipolar MAX6 MAX7

16 MHz Op Amps with Disable MAX6 MAX7 TOP VIEW MAX6 MAX66 MAX67 µmax/so V CC V CC OUT V EE 6 7 MAX68 MAX69 MAX7 SO 9 8 INB- OUTB OUTA INA- INA+ DISABLEA DISABLEB V EE V EE N.C Pin Configurations MAX68 MAX69 MAX7 QSOP 6 V CC V CC N.C. N.C. INB+ DISABLE IN- IN+ V EE OUTA INA- INA+ DISABLEA DISABLEB V EE V EE V CC V CC N.C. N.C. INB+ INB- OUTB 9 N.C. 6

17 MHz Op Amps with Disable Package Information (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to 8 Ø.±. D TOP VIEW E H X S BOTTOM VIEW 8 DIM A A MIN MAX BSC A. b c D e E H L α S INCHES BSC MILLIMETERS MIN MAX BSC BSC 8LUMAXD.EPS MAX6 MAX7 A A A e b c L α FRONT VIEW SIDE VIEW PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE, 8L umax/usop APPROVAL DOCUMENT CONTROL NO. REV. -6 J 7

18 MHz Op Amps with Disable MAX6 MAX7 Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to N TOP VIEW E H INCHES MILLIMETERS DIM A A MIN.. MAX.69. MIN.. MAX.7. B C e. BSC.7 BSC E H L VARIATIONS: DIM D D D INCHES MILLIMETERS MIN MAX MIN MAX N MS AA AB AC SOICN.EPS D A C e B A FRONT VIEW L SIDE VIEW -8 PROPRIETARY INFORMATION TITLE: PACKAGE OUTLINE,." SOIC APPROVAL DOCUMENT CONTROL NO. REV. - B 8

19 MHz Op Amps with Disable Package Information (continued) (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to QSOP.EPS MAX6 MAX7 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. Maxim Integrated Products, San Gabriel Drive, Sunnyvale, CA Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.