Ultra-High-Speed, Low-Distortion, Differentialto-Single-Ended

Transcription

1 9; Rev ; /99 EALUATION KIT AAILABLE Ultra-High-Speed, Low-Distortion, Differentialto-Single-Ended General Description The / differential line receivers offer unparalleled high-speed, low-distortion performance. Using a three op amp instrumentation amplifier architecture, these ICs have symmetrical differential inputs and a single-ended output. They operate from ±5 supplies and are capable of driving a Ω load to ±.7. The has an internally set closed-loop gain of +/, while the is compensated for gains of +/ or greater, set by an external resistor. A low-power enable mode reduces current consumption to.5ma. Using current-feedback techniques, the / achieve a 55MHz bandwidth while maintaining up to a 5/µs slew rate. Excellent differential gain/phase and noise specifications make these amplifiers ideal for a wide variety of video and RF signal-processing applications. An evaluation kit is available to speed design. Features 5/µs Slew Rate () +/ Internally Fixed Gain () External Gain Selection (, A CL +/) 55MHz -db Bandwidth -6dB SFDR at 5MHz Low Differential Gain/Phase:.7%/.5 Low Noise: 5n/ Hz at f IN = khz Low-Power Disable Mode Reduces Quiescent Current to.5ma / Applications Differential-to-Single-Ended Conversion Twisted-Pair to Coaxial Converter High-Speed Instrumentation Amplifier Data Acquisition Medical Instrumentation High-Speed Differential Line Receiver PART ESE ESE Ordering Information TEMP. RANGE PIN-PACKAGE - C to +85 C 6 Narrow SO - C to +85 C 6 Narrow SO Typical Operating Circuit Pin Configuration +5 TOP IEW.µF CC CC 6 5 GND OUT SIGNAL IN+ EN CC IN- REF GND OUT 75Ω 75Ω IN- N.C. (RG) N.C. (RG) IN REF.µF 8 9 EN ( ) ARE FOR ONLY. SO Maxim Integrated Products For free samples & the latest literature: or phone For small orders, phone

2 / ABSOLUTE MAXIMUM RATINGS CC to...+ oltage on IN+, IN-, EN, OUT+, OUT-, RG, REF...( -.) to ( CC +.) Current Into IN+, IN-, RG, EN...mA Output Short-Circuit Duration...Indefinite to GND 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 Continuous Power Dissipation (T A = +7 C) 6-Pin Narrow SO (derate mw/ C above +7 C)...6mW Operating Temperature Range...- C to +85 C Storage Temperature Range C to +5 C Lead Temperature (soldering, sec)...+ C ( CC = +5, EE =, EN =, CM =, R L =, REF = GND, ACL = +/, T A = T MIN to T MAX, unless otherwise noted. Typical values are at T A = +5 C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Operating Supply oltage Range Guaranteed by PSRR test ±.5 ±5.5 Input Common-Mode oltage Range Differential Input oltage Range Input Offset oltage Input Offset-oltage Temperature Coefficient Input Bias Current Input Offset Current Differential Input Resistance Gain Gain Error Gain-Error Drift Output oltage Swing Output Current Drive Power-Supply Rejection Ratio Common-Mode Rejection Ratio Disable Output Resistance EN Logic Low Threshold EN Logic High Threshold EN Logic Input Low Current EN Logic Input High Current Quiescent Current CM DIFF OS TC OS I B IL IH I IL I IH Guaranteed by CMRR test Guaranteed by output swing test I OS R IN -.9 IN CM +.9 A - OUT + - OUT +, R L = Ω R L = Ω OUT R L = Ω R L = 5Ω I OUT R L = Ω PSRR S = ±.5 to ±5.5 CMRR -.9 CM +.9 R OUT(OFF) EN =, -.5 OUT +.5, I Q EN = EN = 5 IN =, EN = 5 IN =, EN = ±. ±.7 ±. ± ( + 6/R G ) m µ/ C µa µa kω / % %/ C ma db db kω µa µa ma

3 Ultra-High Speed, Low-Distortion, Differentialto-Single-Ended AC ELECTRICAL CHARACTERISTICS ( CC = +5, =, EN = 5, R L = Ω, REF = GND, A CL = +/, T A = +5 C, unless otherwise noted.) Settling Time SFDR PARAMETER Small-Signal -db Bandwidth Large-Signal -db Bandwidth.dB Gain Flatness Slew Rate (Note ) Rise Time (Note ) Fall Time (Note ) nd-harmonic Distortion rd-harmonic Distortion Differential Phase Error Differential Gain Error Input Noise oltage Density Input Noise Current Density Output Impedance Enable Time Disable Time Power-Up Time Power-Down Time SYMBOL BW SS BW LS SR t RISE t FALL DP DG e N i N Z OUT t SHDN(ON) t SHDN(OFF) t ON t OFF OUT = mp-p OUT = p-p OUT = mp-p OUT = step OUT = step OUT = step Settle to.%, OUT = step OUT = p-p NTSC, R L = 5Ω f = khz (Note ) f = khz CONDITION MIN TYP MAX OUT =.5 step 6 OUT = step OUT = step OUT = step OUT =.5 step OUT = p-p OUT = p-p f C = khz f C = MHz f C = MHz f C = khz f C = MHz f C = MHz f C = khz f C = MHz UNITS MHz MHz MHz /µs ps ns dbc degrees NTSC, R L = 5Ω.7 % f = MHz IN =, OUT settle to within % IN =, OUT settle to within % IN =, OUT settle to within % IN =, OUT settle to within % f C = MHz /µs ps dbc dbc n/ Hz pa/ Hz Ω ns ns µs µs / Note : Input step voltage has <ps rise (fall) time. Measured at the output from % to 9% (9% to %) level. Note : Includes the current noise contribution through the on-die feedback resistor.

4 / Typical Operating Characteristics ( CC = +5, =, EN = 5, IN = IN + - IN -, R L = Ω, REF = GND, A = +/, T A = +5 C, unless otherwise noted.) SMALL-SIGNAL GAIN OUT = mp-p k M M M toc SMALL-SIGNAL GAIN OUT = mp-p -6 k M M M toc GAIN FLATNESS OUT = mp-p -. k M M M toc.6.5. GAIN FLATNESS OUT = mp-p toc 5 LARGE-SIGNAL GAIN OUT = p-p toc5 LARGE-SIGNAL GAIN OUT = p-p toc k M M M k M M M -6 k M M M SMALL-SIGNAL PULSE RESPONSE SMALL-SIGNAL PULSE RESPONSE LARGE-SIGNAL PULSE RESPONSE 5m/div toc7 5m/div toc8 5m/div toc9 5m/div 5m/div 5m/div 5ns/div 5ns/div 5ns/div

5 Typical Operating Characteristics (continued) ( CC = +5, =, EN = 5, IN = IN + - IN -, R L = Ω, REF = GND, A = +/, T A = +5 C, unless otherwise noted.) 5m/div 5m/div k M LARGE-SIGNAL PULSE RESPONSE 5ns/div nd HARMONIC M OUT = p-p toc toc M SLEW RATE (/µs) SLEW RATE vs. OLTAGE SWING OLTAGE SWING (p-p) - OUT = p-p nd HARMONIC k M M M /5toc toc PHASE (degrees) GAIN (%) DIFFERENTIAL GAIN AND PHASE IRE IRE vs. LOAD RESISTANCE -, OUT = p-p nd HARMONIC k k LOAD RESISTANCE (Ω) toc toc5 / vs. LOAD RESISTANCE -, OUT = p-p nd HARMONIC k k LOAD RESISTANCE (Ω) toc6 vs. OLTAGE SWING nd HARMONIC OLTAGE SWING (p-p) toc7 vs. OLTAGE SWING nd HARMONIC OLTAGE SWING (p-p) toc8 5

6 / Typical Operating Characteristics (continued) ( CC = +5, =, EN = 5, IN = IN + - IN -, R L = Ω, REF = GND, A = +/, T A = +5 C, unless otherwise noted.) OLTAGE () OLTAGE SWING vs. LOAD RESISTANCE 8 6 LOAD RESISTANCE (Ω) POWER-SUPPLY REJECTION RATIO /5toc /5toc OLTAGE NOISE (n/ Hz) - - OLTAGE NOISE DENSITY k k k M M COMMON-MODE REJECTION /5toc /5toc CURRENT NOISE (pa/ Hz) CURRENT NOISE DENSITY k k k M M CLOSED-LOOP IMPEDANCE /5toc toc5 PSRR (db) - - CMR (db) - - ZOUT (Ω) k M M M -8 k M M M -. k M M M SHUTDOWN PULSE.5/div /div SHUTDOWN RESPONSE /5toc6 RISO (Ω) 8 6 RECOMMENDED ISOLATION RESISTANCE vs. CAPACITIE LOAD toc7 OFFSET OLTAGE (m) - OFFSET OLTAGE vs. TEMPERATURE /5toc8 ns/div CAPACITIE LOAD (pf) TEMPERATURE ( C) 6

7 Typical Operating Characteristics (continued) ( CC = +5, =, EN = 5, IN = IN + - IN -, R L = Ω, REF = GND, A = +/, T A = +5 C, unless otherwise noted.) BIAS CURRENT (µa) 8 6 BIAS CURRENT vs. TEMPERATURE TEMPERATURE ( C) /5toc9 QUIESCENT CURRENT (ma) QUIESCENT CURRENT vs. TEMPERATURE EN = TEMPERATURE ( C) /5toc QUIESCENT CURRENT (ma) 5 QUIESCENT CURRENT vs. TEMPERATURE EN = GND TEMPERATURE ( C) /5toc / Pin Description PIN FUNCTION No Connection. Not internally connected. Connect to GND for best AC performance.,, CC Positive Power-Supply Input. Bypass with a.µf capacitor to GND. IN- Inverting Amplifier Input, 5 NAME N.C., 5 RG Resistor Gain Input. Connect a resistor between these pins to set closed-loop gain (Figure ). 6 6 IN+ Noninverting Amplifier Input 7, 8, 7, 8, Negative Supply Input. Bypass with a.µf capacitor. 9 9 EN Active-High Enable Input. Connect to CC for normal operation. Connect to GND for disable mode. REF Reference Input. Connect to midpoint of the two power supplies. 5 5 OUT Amplifier Output 6 6 GND Ground 7

8 / R GAIN RG RG GAIN = + Figure. Setting the Amplifier Gain 6 R GAIN Detailed Description The / differential-to-single-ended line receivers offer high-speed and low-distortion performance, and are ideally suited for video and RF signal-processing applications. These receivers offer a small-signal bandwidth of 55MHz and have a high slew rate of up to 5/µs. Their ma output capability allows them to be directly coupled to data acquisition systems. Applications Information Grounding Bypassing Use the following high-frequency design techniques when designing the PC board for the /. Use a multilayer board with one layer dedicated as the ground plane. Do not use wire wrap or breadboards due to high inductance. Avoid IC sockets due to high parasitic capacitance and inductance. Bypass supplies with a.µf capacitor. Use surface-mount capacitors to minimize lead inductance. Keep signal lines as short and straight as possible. Do not make 9 turns. Use rounded corners. Do not cross signal paths if possible. Ensure that the ground plane is free from voids. IN+ IN Figure. Using an Isolation Resistor for High Capacitive Loads Setting Gain () The is stable with a minimum gain configuration of +/. R GAIN, connected between the RG pins, sets the gain of this device as shown in Figure. Calculate the expected gain as follows: Gain = ( + 6 / R GAIN ) Driving Capacitive Loads The / are designed to drive capacitive loads. However, excessive capacitive loads may cause ringing or instability at the output as the phase margin of the device reduces. Adding a small series isolation resistor at the output helps reduce the ringing but slightly increases gain error (Figure ). For recommended values, see Typical Operating Characteristics. R ISO Coaxial Line Driver The / are well suited to drive coaxial cables. Their high output current capability can easily drive the 75Ω characteristic impedance of common coaxial cables. Adjust the gain of the to compensate for cable losses to maintain the required levels at the input of the next stage. TRANSISTOR COUNT: 5 SUBSTRATE CONNECTED TO EE C LOAD Chip Information Low-Power Enable Mode The / are disabled when EN goes low. This reduces supply current to only.5ma. As the output becomes higher impedance, the effective impedance at the output for the is.8kω. The effective output impedance for the is.8kω plus R GAIN. 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. 8 Maxim Integrated Products, San Gabriel Drive, Sunnyvale, CA Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.