400MHz, Ultra-Low-Distortion Op Amps

Transcription

1 9; Rev ; /97 EVALUATION KIT AVAILABLE MHz, Ultra-Low-Distortion Op Amps General Description The MAX8/MAX9/MAX8/MAX9 op amps combine ultra-high-speed performance with ultra-lowdistortion operation. The MAX8 is compensated for unity-gain stability; the MAX9, MAX8, and MAX9 are compensated for minimum closed-loop gains (AVCL) of V/V, 5V/V, and V/V, respectively. The MAX8 delivers a MHz unity-gain bandwidth with a V/µs slew rate. An ultra-low-distortion design provides an unprecedented spurious-free dynamic range of -9dBc (MAX8) at 5MHz (V = Vp-p, RL = Ω), making these amplifiers ideal for high-performance RF signal processing. These high-speed op amps feature a wide output voltage swing and a high-current output-drive capability of 9mA. Applications High-Speed ADC/DAC Preamp RGB and Composite Video High-Performance Receivers Pulse/RF Amplifier Active Filters Ultrasound Broadcast and High-Definition TV Typical Application Circuit Ω Ω Features High Speed: MHz Unity-Gain Bandwidth (MAX8) 5MHz db Bandwidth (AVCL = +, MAX9) MHz db Bandwidth (AVCL = +5, MAX8) MHz db Bandwidth (AVCL = +, MAX9) V/µs Slew Rate Excellent Spurious-Free Dynamic Range: -9dBc at fc = 5MHz (MAX8) -9dBc at fc = 5MHz (MAX9) MHz.dB Gain Flatness (MAX8) High Full-Power Bandwidth: MHz (MAX8, VO = Vp-p) High Output Drive: 9mA Output Short-Circuit Protected Low Differential Gain/Phase:.%/.8 Ordering Information PART MAX8ESA MAX9ESA MAX8ESA MAX9ESA TOP VIEW TEMP. RANGE - C to +85 C - C to +85 C - C to +85 C - C to +85 C P-PACKAGE 8 SO 8 SO 8 SO 8 SO Pin Configuration MAX8/MAX9/MAX8/MAX9 5.6Ω* Ω MAX9 Ω -BIT ADC N.C. - + MAX8 MAX9 MAX8 MAX V CC V CC 6Ω* Ω * USED TO MATCH A 5Ω SOURCE IMPEDANCE V EE SO 5 V EE DIFFERENCE AMPLIFIER/ADC PREAMPLIFIER Maxim Integrated Products For free samples & the latest literature: or phone

2 MHz, Ultra-Low-Distortion Op Amps MAX8/MAX9/MAX8/MAX9 ABSOLUTE MAXIMUM RATGS Supply Voltage (V CC to V EE )...V Voltage on Any Pin to Ground or Any Other Pin...(V EE -.V) to (V CC +.V) Short-Circuit Duration ( to )...Continuous Continuous Power Dissipation (T A = +7 C) SO (derate 5.88mW/ C above +7 C)...7mW Operating Temperature Range...- C to +85 C Storage Temperature Range...5 C to +5 C Junction Temperature...+5 C Lead Temperature (soldering, sec)...+ 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 (V CC = +5V, V EE = V, T A = T M to T MAX, typical values are at T A = +5 C, unless otherwise noted.) PARAMETER DC SPECIFICATIONS (R L = ) Input Offset Voltage Input Offset Voltage Drift Input Bias Current Input Offset Current Common-Mode Input Resistance Common-Mode Input Capacitance Input Voltage Noise Integrated Voltage Noise Input Current Noise Integrated Current Noise Common-Mode Input Voltage Common-Mode Rejection Power-Supply Rejection Quiescent Supply Current Output Current Drive Short-Circuit Output Current SYMBOL V OS TCV OS I B I OS R CM C CM i n CMR PSR I S I I SC V = V V = V V = V, V = -V OS V = V, V = -V OS Either input Either input f = khz V CM = ±.5V V S = ±.5V to ±5.5V V = V R L = Ω, T A = C to +85 C Short to ground CONDITIONS M TYP MAX Open-Loop Voltage Gain A OL V = ±.V, V CM = V, R L = Ω 7 Output Voltage Swing AC SPECIFICATIONS (R L = Ω) db Bandwidth e n E nrms I n V CM V BW db f = khz f B = MHz to MHz f B = MHz to MHz R L = R L = Ω V.V RMS MAX8 MAX9 MAX8 MAX to.9 to..8.5 to.7 to UNITS mv µv/ C µa µa MΩ pf nv/ Hz µv RMS pa/ Hz na RMS V db db db ma V ma ma MHz

3 MHz, Ultra-Low-Distortion Op Amps ELECTRICAL CHARACTERISTICS (continued) (V CC = +5V, V EE = V, T A = T M to T MAX, typical values are at T A = +5 C, unless otherwise noted.) PARAMETER SYMBOL AC SPECIFICATIONS (R L = Ω) (continued) Full-Power Bandwidth.dB Gain Flatness Slew Rate Settling Time Rise/Fall Times Differential Gain Differential Phase Input Capacitance Output Resistance Spurious-Free Dynamic Range FPBW BW.dB SR t S t R, t F DG DP C R SFDR V = Vp-p MAX8, A VCL = + MAX9, A VCL = + MAX8, A VCL = +5 MAX9, A VCL = + -V V V -V V V % to 9% CONDITIONS f =.58MHz, R L = 5Ω f =.58MHz, R L = 5Ω f = MHz MAX8, V = Vp-p, A VCL = + MAX9, V = Vp-p, A VCL = + MAX8, V = Vp-p, A VCL = +5 MAX8 MAX9 MAX8 MAX9 To.% To.% -V V V mv V 5mV f C = 5MHz, R L = Ω f C = MHz, R L = Ω f C = 5MHz, R L = Ω f C = MHz, R L = Ω f C = 5MHz, R L = Ω f C = MHz, R L = Ω M TYP MAX UNITS MHz MHz V/µs ns ns % degrees pf Ω dbc MAX8/MAX9/MAX8/MAX9 MAX9, V = Vp-p, A VCL = + f C = 5MHz, R L = Ω f C = MHz, R L = Ω -8-8 MAX8 9 Third-Order Intercept IP f C = MHz MAX9 MAX8 6 6 dbm MAX9

4 MHz, Ultra-Low-Distortion Op Amps MAX8/MAX9/MAX8/MAX9 Typical Operating Characteristics (V CC = +5V, V EE = V, R L = Ω, T A = +5 C, unless otherwise noted.) NORMALIZED GA (db) NORMALIZED GA (db) NORMALIZED GA (db) MAX8 SMALL-SIGNAL GA vs. FREQUENCY V mvp-p A VCL = + A VCL = +. MAX9 LARGE-SIGNAL GA vs. FREQUENCY V = Vp-p A VCL = + MAX8/MAX9 LARGE-SIGNAL GA vs. FREQUENCY V = Vp-p MAX9 A VCL = + MAX8 A VCL = +5. MAX8/9-A MAX8/9-D MAX8/9 TOCG GA (db) NORMALIZED GA (db) MAX8 LARGE-SIGNAL GA vs. FREQUENCY V = Vp-p A VCL = +. MAX8 SMALL-SIGNAL GA vs. FREQUENCY V mvp-p A VCL = MAX8 HARMONIC DISTORTION vs. FREQUENCY V = Vp-p A VCL = + ND HARMONIC. MAX8/9-B MAX8/9 TOCE MAX8/9-H NORMALIZED GA (db) NORMALIZED GA (db) MAX9 SMALL-SIGNAL GA vs. FREQUENCY V mvp-p A VCL = +5 A VCL = +. MAX9 SMALL-SIGNAL GA vs. FREQUENCY V mvp-p A VCL = A VCL = MAX9 HARMONIC DISTORTION vs. FREQUENCY V = Vp-p A VCL = + ND HARMONIC. MAX8/9-C MAX8/9 TOCF MAX8/9-i

5 MHz, Ultra-Low-Distortion Op Amps Typical Operating Characteristics (continued) (V CC = +5V, V EE = V, R L = Ω, T A = +5 C, unless otherwise noted.) MAX8/MAX9 HARMONIC DISTORTION vs.frequency V = Vp-p MAX8: A VCL = +5 MAX9: A VCL = + RD HARMONIC ND HARMONIC. MAX8/MAX9 HARMONIC DISTORTION vs. LOAD V = Vp-p f O = 5MHz MAX8: A VCL = +5 MAX9: A VCL = + ND HARMONIC RESISTIVE LOAD (Ω) MAX8/MAX9 HARMONIC DISTORTION vs. PUT SWG V = Vp-p f O = 5MHz MAX8: A VCL = +5 MAX9: A VCL = + ND HARMONIC. RESISTIVE LOAD (Ω) MAX8/9 TOCJ MAX8/9 TOCM MAX8/9 TOCP THIRD-ORDER TERCEPT (dbm) MAX8 HARMONIC DISTORTION vs. LOAD A VCL = + V = Vp-p f O = MHz MAX8 HARMONIC DISTORTION vs. PUT SWG A VCL = + V = Vp-p f O = MHz ND HARMONIC ND HARMONIC RESISTIVE LOAD (Ω). PUT SWG (Vp-p) MAX9 TWO-TONE THIRD-ORDER TERCEPT vs. FREQUENCY 5 MAX8/9-K MAX8/9-N MAX8/9-Q NOISE (nv Hz) MAX9 HARMONIC DISTORTION vs. LOAD A VCL = + V = Vp-p f O = MHz ND HARMONIC RESISTIVE LOAD (Ω) MAX9 HARMONIC DISTORTION vs. PUT SWG A VCL = + V = Vp-p f O = MHz ND HARMONIC. PUT SWG (Vp-p) PUT NOISE vs. FREQUENCY k k k M FREQUENCY (Hz) MAX8/9-L MAX8/9-O MAX8/9-TOCR MAX8/MAX9/MAX8/MAX9

6 MHz, Ultra-Low-Distortion Op Amps MAX8/MAX9/MAX8/MAX9 DIFF PHASE (deg) DIFF GA (%) Typical Operating Characteristics (continued) (V CC = +5V, V EE = V, R L = Ω, T A = +5 C, unless otherwise noted.) DIFF PHASE (deg) DIFF GA (%). A VCL = +V A VCL = +V A VCL = +V A VCL = +V MAX8 DIFFERENTIAL GA AND PHASE (R L = 5Ω) MAX9 DIFFERENTIAL GA AND PHASE (R L = 75Ω) MAX8 SMALL-SIGNAL PULSE RESPONSE (A VCL = +) MAX8/9-Y MAX8/9-S MAX8/9-V DIFF PHASE (deg) DIFF GA (%) DIFF PHASE (deg) DIFF GA (%) A VCL = +5V A VCL = +5V MAX8 DIFFERENTIAL GA AND PHASE (R L = 75Ω) A VCL = +V.6 A VCL = +V MAX8 DIFFERENTIAL GA AND PHASE (R L = 5Ω) MAX8 SMALL-SIGNAL PULSE RESPONSE (A VCL = +) MAX8/9-Z MAX8/9-T MAX8/9-W DIFF PHASE (deg) DIFF GA (%) DIFF PHASE (deg) DIFF GA (%). A VCL = +V A VCL = +V A VCL = +V MAX9 DIFFERENTIAL GA AND PHASE (R L = 5Ω) MAX9 DIFFERENTIAL GA AND PHASE (R L = 5Ω) A VCL = +V MAX8 LARGE-SIGNAL PULSE RESPONSE (A VCL = +) MAX8/9-AA (5mV/div) MAX8/9-U MAX8/9-X (mv/div) (mv/div) TIME (ns/div) TIME (ns/div) TIME (ns/div) 6

7 MHz, Ultra-Low-Distortion Op Amps Typical Operating Characteristics (continued) (V CC = +5V, V EE = V, R L = Ω, T A = +5 C, unless otherwise noted.) (5mV/div) (mv/div) MAX8 LARGE-SIGNAL PULSE RESPONSE (A VCL = +) TIME (ns/div) MAX8/9-BB MAX8 SMALL-SIGNAL PULSE RESPONSE (A VCL = +5) TIME (ns/div) MAX8/9EE MAX9 SMALL-SIGNAL PULSE RESPONSE (A VCL = +) MAX8/9HH (mv/div) (V/div) MAX9 SMALL-SIGNAL PULSE RESPONSE (A VCL = +) TIME (ns/div) MAX8 LARGE-SIGNAL PULSE RESPONSE (A VCL = +5) TIME (ns/div) MAX8/9-CC MAX8/9FF MAX9 LARGE-SIGNAL PULSE RESPONSE (A VCL = +) MAX8/9ii (5mV/div) (5mV/div) MAX9 LARGE-SIGNAL PULSE RESPONSE (A VCL = +) TIME (ns/div) MAX9 SMALL-SIGNAL PULSE RESPONSE (A VCL = +) TIME (ns/div) MAX8/9-DD MAX8/9GG MAX9 LARGE-SIGNAL PULSE RESPONSE (A VCL = +) MAX8/9JJ MAX8/MAX9/MAX8/MAX9 (5mV/div) (5mV/div) (5mV/div) TIME (ns/div) TIME (ns/div) TIME (ns/div) 7

8 MHz, Ultra-Low-Distortion Op Amps MAX8/MAX9/MAX8/MAX9 POWER-SUPPLY REJECTION (db) PUT SWG (VPEAK) CURRENT (µa) Typical Operating Characteristics (continued) (V CC = +5V, V EE = V, R L = Ω, T A = +5 C, unless otherwise noted.) POWER-SUPPLY REJECTION vs. FREQUENCY MAX8/MAX8 MAX9/ MAX9. PUT SWG vs. LOAD RESISTANCE LOAD RESISTANCE (Ω) PUT OFFSET CURRENT vs. TEMPERATURE TEMPERATURE ( C) MAX8/9-KK MAX8/9-NN MAX8/9-QQ COMMON-MODE REJECTION (db) (mv) CURRENT (ma) COMMON-MODE REJECTION vs. FREQUENCY MAX9/ MAX9 MAX8/MAX8. PUT OFFSET vs. TEMPERATURE TEMPERATURE ( C) POWER-SUPPLY CURRENT vs. TEMPERATURE POSITIVE SUPPLY CURRENT NEGATIVE SUPPLY CURRENT TEMPERATURE ( C) MAX8/9-LL MAX8/9-OO MAX8/9-RR PUT IMPEDANCE (Ω) CURRENT (µa) PUT SWG (V) CLOSED-LOOP PUT IMPEDANCE vs. FREQUENCY. PUT BIAS CURRENT vs. TEMPERATURE TEMPERATURE ( C) PUT SWG vs. TEMPERATURE R L = R L = Ω. R L = Ω -. R L = TEMPERATURE ( C) MAX8/9-MM MAX8/9-PP MAX8/9-SS 8

9 MHz, Ultra-Low-Distortion Op Amps Pin Description P NAME FUNCTION N.C. No Connection. Not internally connected. - Inverting Input + Noninverting Input, 5 V EE Negative Power Supply, connect to V DC. 6 Amplifier Output 7, 8 V CC Positive Power Supply, connect to +5V DC. Detailed Description Choosing Resistor Values Unity-Gain Configuration The MAX8 is internally compensated for unity gain. When configured for unity gain, the device requires a small resistor in series with the feedback path. This resistor improves the AC response by reducing the Q of the tank circuit, which is formed by parasitic feedback inductance and capacitance. R G V PART MAX8 MAX9 MAX8 MAX9 R F R F (Ω) R G (Ω) R S C L GA (V/V) 5 R L 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 will 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 +, using kω resistors combined with pf of input capacitance and.5pf of board capacitance, will cause a feedback pole at 8MHz. If this pole is within the anticipated amplifier bandwidth, it will jeopardize stability. Reducing these kω resistors to Ω will extend 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. The MAX8/MAX9/MAX8/MAX9 are ultralow-distortion, high-bandwidth op amps. The output distortion will be degraded as the total load resistance seen by the amplifier decreases. To minimize distortion products, keep the input and gain-setting resistors relatively large. A 5Ω feedback resistor combined with an appropriate input resistor to set the gain will provide excellent AC performance without significantly increasing distortion. ISOLATION RESISTANCE (Ω) MAX8 MAX8 MAX9/MAX CAPACITANCE (pf) MAX8/9-B MAX8/MAX9/MAX8/MAX9 Figure a. Using an Isolation Resistor for High Capacitive Loads Figure b. Optimal Isolation Resistor (R S ) vs. Capacitive Load 9

10 MHz, Ultra-Low-Distortion Op Amps MAX8/MAX9/MAX8/MAX9 Driving Capacitive Loads The MAX8/MAX9/MAX8/MAX9 are optimized for AC performance. They are not designed to drive highly reactive loads. Reactive loads will decrease phase margin and may produce excessive ringing and oscillation. Figure a shows a circuit that CLOSED-LOOP GA (db) R S = Ω A VCL = + C L = 5pF C L = pf. C L = 5pF Figure a. MAX8 Response vs. Capacitive Load No Resistive (R S ) Isolation (circuit shown in Figure a) NORMALIZED GA (db) R S = Ω A VCL = +5. C L = 5pF C L = pf C L = 5pF MAX8/9-A MAX8/9-C eliminates this problem, and Figure b is a graph of the optimal isolation resistor (R S ) vs. capacitive load. Figures a d show how a capacitive load causes excessive peaking of the amplifier s bandwidth if the capacitive load is not isolated (R S ) from the amplifier. A small isolation resistor (usually 5Ω to Ω) placed CLOSED-LOOP GA (db) R S = Ω A VCL = + C L = 5pF C L = pf C L = 5pF. Figure b. MAX9 Response vs. Capacitive Load No Resistive (R S ) Isolation (circuit shown in Figure a) NORMALIZED GA (db) R S = Ω A VCL = +. C L = 5pF C L = 5pF C L = pf MAX8/9-B MAX8/9-D Figure c. MAX8 Response vs. Capacitive Load No Resistive (R S ) Isolation (circuit shown in Figure a) Figure d. MAX9 Response vs. Capacitive Load No Resistive (R S ) Isolation (circuit shown in Figure a)

11 MHz, Ultra-Low-Distortion Op Amps before the reactive load prevents ringing and oscillation. At higher capacitive loads, AC performance will be controlled by the interaction of the load capacitance and isolation resistor. Figures a c show the effect of an isolation resistor on the MAX8/MAX9/ MAX8/MAX9 closed-loop response. 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 capacitance of the transmission line is essentially eliminated. ADC Input Buffers 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 the section Driving Capacitive Loads). In addition, a high-speed ADC s input impedance often changes very rapidly during the conversion cycle, requiring an amplifier with very low output impedance at high frequencies to maintain measurement accuracy. The combination of high speed, fast slew rate, low noise, and a low and stable distortion over load makes the MAX8/MAX9/ MAX8/MAX9 ideally suited for use as buffer amplifiers in high-speed ADC applications. CLOSED-LOOP GA (db) C L = pf A VCL = + R S = Ω. R S = Ω R S = Ω MAX8/9A CLOSED-LOOP GA (db) C L = pf A VCL = + R S = 5Ω. R S = 8.Ω Figure b. MAX8 Response vs. Capacitive Load with Resistive (R S ) Isolation (circuit shown in Figure a) NORMALIZED GA (db) C L = pf A V = +5 R S = 8.Ω R S = 5Ω R S = 7Ω. MAX8/9B MAX8/9C MAX8/MAX9/MAX8/MAX9 Figure a. MAX8 Response vs. Capacitive Load with Resistive (R S ) Isolation (circuit shown in Figure a) Figure c. MAX8/MAX9 Response vs. Capacitive Load with Resistive (R S ) Isolation (circuit shown in Figure a)

12 MHz, Ultra-Low-Distortion Op Amps MAX8/MAX9/MAX8/MAX9 Chip Information TRANSISTOR COUNT: 57 SUBSTRATE CONNECTED TO V EE Package Information SOICN.EPS 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 986 (8) Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.