connection diagram plastic mini-dip (n) cerdip (q) and plastic soic (r) packages rev. b information furnished by analog devices is believed to be accurate and reliable. however, no responsibility is assumed by analog devices for its use, nor for any infringements of patents or other rights of third parties which may result from its use. no license is granted by implication or otherwise under any patent or patent rights of analog devices. a dual precision, 500 ns settling, bifet op amp ad746 one technology way, p.o. box 9106, norwood, ma 02062-9106, u.s.a. tel: 617/329-4700 fax: 617/326-8703 features ac performance 500 ns settling to 0.01% for 10 v step 75 v/ m s slew rate 0.0001% total harmonic distortion (thd) 13 mhz gain bandwidth internal compensation for gains of +2 or greater dc performance 0.5 mv max offset voltage (ad746b) 10 m v/ 8 c max drift (ad746b) 175 v/mv min open loop gain (ad746b) 2 m v p-p noise, 0.1 hz to 10 hz available in plastic mini-dip, cerdip and surface mount packages available in tape and reel in accordance with eia-481a standard mil-std-883b processing also available single version: ad744 applications dual output buffers for 12- and 14-bit dacs input buffers for precision adcs, wideband preamplifiers and low distortion audio circuitry product description the ad746 is a dual operational amplifier, consisting of two ad744 bifet op amps on a single chip. these precision monolithic op amps offer excellent dc characteristics plus rapid settling times, high slew rates and ample bandwidths. in addition, the ad746 provides the close matching ac and dc characteristics inherent to amplifiers sharing the same monolithic die. the single pole response of the ad746 provides fast settling: 500 ns to 0.01%. this feature, combined with its high dc precision, makes it suitable for use as a buffer amplifier for 12- or 14-bit dacs and adcs. furthermore, the ad746s low total harmonic distortion (thd) level of 0.0001% and very close matching ac characteristics make it an ideal amplifier for many demanding audio applications. the ad746 is internally compensated for stable operation as a unity gain inverter or as a noninverting amplifier with a gain of 2 or greater. it is available in four performance grades. the ad746j is rated over the commercial temperature range of 0 to +70 c. the ad746a and ad746b are rated over the industrial temperature range of C40 c to +85 c. the ad746s is rated over the military temperature range of C55 c to +125 c and is available processed to mil-std-883b, rev. c. the ad746 is available in three 8-pin packages: plastic mini dip, hermetic cerdip and surface mount (soic). product highlights 1. the ad746 offers exceptional dynamic response for high speed data acquisition systems. it settles to 0.01% in 500 ns and has a 100% tested minimum slew rate of 50 v/ m s (ad746b). 2. outstanding dc precision is provided by a combination of analog devices advanced processing technology, laser wafer drift trimming and well-matched ion-implanted jfets. input offset voltage, input bias current and input offset current are specified in the warmed-up condition and are 100% tested. 3. differential and multichannel systems will benefit from the ad746s very close matching of ac characteristics. input offset voltage specs are fully tested and guaranteed to a maximum of 0.5 mv (ad746b). 4. the ad746 has very close, guaranteed matching of input bias current between its two amplifiers. 5. unity gain stable version ad712 also available.
rev. b C2C ad746Cspecifications (@ +25 8 c and 6 15 v dc, unless otherwise noted) ad746j/a ad746b ad746s model conditions min typ max min typ max min typ max units input offset voltage 1 initial offset 0.3 1.5 0.25 0.5 0.3 1.0 mv offset t min to t max 2.0 0.7 1.5 mv vs. temperature 12 20 5 10 12 20 m v/ c vs. supply 2 (psrr) 80 95 84 100 80 95 db vs. supply (psrr) t min to t max 80 84 80 db long term stability 15 15 15 m v/month input bias current 3 either input v cm = 0 v 110 250 110 150 110 250 pa either input @ t max v cm = 0 v 2.5/7 5.7/16 7 9.6 113 256 na either input v cm = +10 v 145 350 145 200 145 350 pa offset current v cm = 0 v 45 125 45 75 45 125 pa offset current @ t max v cm = 0 v 1.0/3 2.8/8 3 4.8 45 128 na matching characteristics input offset voltage 0.6 1.5 0.3 0.5 0.6 1.0 mv input offset voltage t min to t max 2.0 0.7 1.5 mv input offset voltage drift 20 20 20 m v/ c input bias current 125 75 125 pa crosstalk @ 1 khz 120 120 120 db @ 100 khz 90 90 90 db frequency response gain bw, small signal g = C1 8 13 9 13 8 13 mhz slew rate, unity gain g = C1 45 75 50 75 45 75 v/ m s full power response v o = 20 v p-p 600 600 600 khz settling time to 0.01% 4 g = 1 0.5 0.75 0.5 0.75 0.5 0.75 m s total harmonic f = 1 khz distortion r1 3 2 k w v o = 3 v rms 0.0001 0.0001 0.0001 % input impedance differential 2.5 l0 1l i 5.5 2.5 l0 1l i 5.5 2.5 l0 1l i 5.5 w i pf common mode 2.5 l0 1l i 5.5 2.5 l0 1l i 5.5 2.5 l0 1l i 5.5 w i pf input voltage range differential 5 20 20 20 v common-mode voltage +14.5, C11.5 +14.5, C11.5 +14.5, C11.5 v over max operating range 6 C11 +13 C11 +13 C11 +13 v common-mode rejection ratio v cm = 10 v 78 88 82 88 78 88 db t min to t max 76 84 80 84 76 84 db v cm = 11 v 72 84 78 84 72 84 db t min to t max 70 80 74 80 70 80 db input voltage noise 0.1 to 10 hz 2 2 2 m v p-p f = 10 hz 45 45 45 nv/ ? hz f = 100 hz 22 22 22 nv/ ? hz f = 1 khz 18 18 18 nv/ ? hz f = 10 khz 16 16 16 nv/ ? hz input current noise f = 1 khz 0.01 0.01 0.01 pa/ ? hz open loop gain v o = 10 v r1 3 2 k w 150 300 175 300 150 300 v/mv t min to t max 75 200 75 200 65 175 v/mv output characteristics voltage r1 3 2 k w +13, C12.5 +13.9, C13.3 +13, C12.5 +13.9, C13.3 +13, C12.5 +13.9, C13.3 v t min to t max 12 +13.8, C13.1 6 12 +13.8, C13.1 6 12 +13.8, C13.1 v current short circuit 25 25 25 ma max capacitive load gain = C1 50 50 50 pf driving capability gain = C10 500 500 500 pf power supply rated performance 15 15 15 v operating range 6 4.5 6 18 6 4.5 6 18 6 4.5 6 18 v quiescent current 7 10 7 8.0 7 10 ma temperature range rated performance 0 to +70/C40 to +85 C40 to +85 C55 to +125 c package options 8-pin plastic mini-dip (n-8) ad746jn 8-pin cerdip (q-8) ad746aq ad746bq ad746sq 8-pin surface mount (r-8) ad746jr tape and reel ad746jr-reel chips ad746schips transistor count 54 54 54
notes 1 input offset voltage specifications are guaranteed after 5 minutes of operation at t a = +25 c. 2 psrr test conditions: +v s = 15 v, Cv s = C12 v to C18 v and +v s = 12 v to 18 v, Cv s = C15 v. 3 bias current specifications are guaranteed maximum at either input after 5 minutes of operation at t a = +25 c. for higher temperature, the current doubles every 10 c. 4 gain = C1, rl = 2 k, cl = 10 pf. 5 defined as voltage between inputs, such that neither exceeds 10 v from ground. 6 typically exceeding C14.1 v negative common-mode voltage on either input results in an output phase reversal. specifications subject to change without notice. specifications in boldface are tested on all production units at final electrical test. results from those tests are used to calculate outgoing quality levels. all min and max specifications are guaranteed, although only those shown in boldface are tested on all production units. absolute maximum ratings 1 supply voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 v internal power dissipation 2 . . . . . . . . . . . . . . . . . . . . . 500 mw input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v s output short circuit duration (for one amplifier) . . . . . . . . . . . . . . . . . . . . . . . indefinite differential input voltage . . . . . . . . . . . . . . . . . . +v s and Cv s storage temperature range (q) . . . . . . . . . . C65 c to +150 c storage temperature range (n, r) . . . . . . . . C65 c to +125 c operating temperature range ad746j . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0 c to +70 c ad746a/b . . . . . . . . . . . . . . . . . . . . . . . . . . C40 c to +85 c ad746s . . . . . . . . . . . . . . . . . . . . . . . . . . . C55 c to +125 c lead temperature range (soldering 60 seconds) . . . . . . . . . . . . . . . . . . . . . . . +300 c esd rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . notes 1 stresses above those listed under absolute maximum ratings may cause permanent damage to the device. this is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. 2 8-pin plastic package: q ja = 100 c/watt, q jc = 50 c/watt 8-pin cerdip package: q ja = 110 c/watt, q jc = 30 c/watt 8-pin small outline package: q ja = 160 c/watt, q jc = 42 c/watt metalization photograph contact factory for latest dimensions. dimensions shown in inches and (mm). warning! esd sensitive device caution esd (electrostatic discharge) sensitive device. electrostatic charges as high as 4000 v readily accumulate on the human body and test equipment and can discharge without detection. although the ad746 features proprietary esd protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. therefore, proper esd precautions are recommended to avoid performance degradation or loss of functionality. ad746 rev. b C3C
ad746 C4C rev. b Ctypical characteristics figure 1. input voltage swing vs. supply voltage figure 4. quiescent current vs. supply voltage figure 7. input bias current vs. common mode voltage figure 2. output voltage swing vs. supply voltage figure 5. input bias current vs. temperature figure 8. short circuit current limit vs. temperature figure 3. output voltage swing vs. load resistance . figure 6. output impedance vs. frequency figure 9. gain bandwidth product vs. temperature
ad746 rev. b C5C figure 12. open loop gain vs. supply voltage figure 15. output swing and error vs. settling time figure 18. slew rate vs. input error signal figure 11. settling time vs. closed loop voltage gain figure 14. large signal frequency response figure 17. input noise voltage spectral density figure 10. open loop gain and phase margin vs. frequency figure 13. common-mode and power supply rejection vs. frequency figure 16. total harmonic distortion vs. frequency using circuit of figure 19
ad746 C6C rev. b power supply bypassing the power supply connections to the ad746 must maintain a low impedance to ground over a bandwidth of 13 mhz or more. this is especially important when driving a significant resistive or capacitive load, since all current delivered to the load comes from the power supplies. multiple high quality bypass capacitors are recommended for each power supply line in any critical application. a 0.1 m f ceramic and a 1 m f tantalum capacitor as shown in figure 20 placed as close as possible to the amplifier (with short lead lengths to power supply common) will assure adequate high frequency bypassing, in most applications. a minimum bypass capacitance of 0.1 m f should be used for any application. if only one of the two amplifiers inside the ad746 is to be utilized, the unused amplifier should be connected as shown in figure 21a. note that the noninverting input should be grounded and that r l and c l are not required. figure 19. thd test circuit figure 22a. unity gain inverter figure 21a. gain of 2 follower figure 21b. gain of 2 follower large signal pulse response figure 21c. gain of 2 follower small signal pulse response figure 22b. unity gain inverter large signal pulse response figure 22c. unity gain inverter small signal pulse response figure 20. power supply bypassing
ad746 rev. b C7C table i. performance summary for the 3 op amp instrumentation amplifier circuit t settle gain r g bandwidth (0.01%) 2 20 k w 2.5 mhz 1.0 m s 10 4.04 k w 1 mhz 2.0 m s 100 404 w 290 khz 5.0 m s figure 25. settling time of the 3 op amp instrumentation amplifier. gain = 10, horizontal scale: 0.5 m s/div, vertical scale: 5 v/div. error signal scale: 0.01%/div. thd performance considerations the ad746 was carefully optimized to offer excellent performance in terms of total harmonic distortion (thd) in signal processing applications. the thd level when operating the ad746 in inverting gain applications will show a gradual rise from the distortion floor of 20 db/decade (see figure 28). in noninverting applications, care should be taken to balance the source impedances at both the inverting and noninverting inputs, to avoid distortion caused by the modulation of input capacitance inherent in all bifet op amps. figure 26. thd measurement, inverter circuit figure 27. thd measurement, follower circuit a high speed 3 or amp instrumentation amplifier circuit the instrumentation amplifier circuit shown in figure 23 can provide a range of gains from 2 up to 1000 and higher. the circuit bandwidth is 2.5 mhz at a gain of 2 and 750 khz at a gain of 10; settling time for the entire circuit is less than 2 m s to within 0.01% for a 10 volt step, (g = 10). figure 23. a high performance, 3 op amp, instrumenta- tion amplifier circuit figure 24. pulse response of the 3 op amp instrumentation amplifier. gain = 10, horizontal scale: 0.5 m s/div, vertical scale: 5 v/div.
ad746 C8C rev. b c1319C10C9/89 printed in u.s.a. figure 28. thd vs. frequency using standard distortion analyzer 20k w 2.21k w 2k w 2k w sine wave generator 20v p-p output level 20v p-p 1 2 3 4 v out #1 + 1/2 ad746 + ? s 1 m f 0.1 m f 7 6 5 8 + 1/2 ad746 v out #2 +v s + 1 m f 0.1 m f crosstalk = 20 log 10 v out #1 v out #2 + 20db figure 29. crosstalk test circuit figure 30. crosstalk vs. frequency outline dimensions dimensions shown in inches and (mm). mini-dip (n) package cerdip (q) package plastic small outline (r) package
package/price information dual precision, 500 ns settling, bifet op amp * this price is provided for budgetary purposes as recommended list price in u.s. dollars per unit in the stated volume. pricing displayed for evaluation boards and kits is based on 1-piece pricing. view pricing and availability for further information. model status package description pin count temperature range price* (100-499) ad746aq production cerdip glass seal 8 industrial - ad746bq production cerdip glass seal 8 industrial - ad746jn production plastic/epoxy dip 8 commercial $4.25 ad746jr production std s.o. pkg (soic) 8 commercial $4.25 ad746jr-reel production std s.o. pkg (soic) 8 commercial - ad746jr-reel7 production std s.o. pkg (soic) 8 commercial - ad746schips production chips/die sales - commercial $32.56 ad746sq production cerdip glass seal 8 military - ad746sq/883b production cerdip glass seal 8 military $47.88
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