12mhz 20v/s g=1,2, 5,10 programmable gain i cmos? instrumentation amplifier preliminary technical data AD8250 rev.pr 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 that may result from its use. specifications subject to change without notice. no license is granted by implication or otherwise under any patent or patent ri ghts of analog devices. trademarks and registered trademarks are the proper ty of their respective companies. one technology way, p.o. box 9106, norwood, ma 02062-9106, u.s.a. tel: 781.329.4700 www.analog.com fax: 781.326.8703 ? 2006 analog devices, inc. all rights reserved. features easy to use programmable gains: 1, 2, 5, 10 digital or pin programmable gain setting temp range -40 c to 85 c excellent dc performance high cmrr 100db g=10 low gain drift: 10ppm/ c low offset drift: 1uv/ c low offset: 70uv g=10 excellent ac performance fast settle time: 0.5us to 0.01% high slew rate: 20v/ s high cmrr over frequency: 80db to 50khz low noise: 13nv hz, g=10 low power: 3.5 ma (typ) supply: 5v to 12v applications data acquisition bio-medical analysis test and measurement high performance system monitoring a1 a0 dgd wr logic AD8250 out +vs -vs ref +in -in figure 1. functional block diagram 1gh z 100mhz 10mhz 1mhz 100khz 10khz 1khz 100hz 30 20 10 0 -10 -20 -30 ga i n ( d b ) frequency figure 2. gain vs frequency general description the AD8250 is a digitally gain programmable instrumentation amplifier that has high g input impedance and low distortion making it suitable for sensor interfacing and driving high sample rate analog to digital converters. it has high bandwidth of 12mhz, low distortion and settle time of 0.5us to 0.01%. offset drift and gain drift are limited to 1uv/ c and 10ppm/ c respectively. in addition to its wide input common-voltage range, it boasts a high common-mode rejection of 80db at g=1 from dc to 50khz. the combination of precision dc performance coupled with high speed capabilities make the AD8250 an excellent candidate for data acquisition and medical applications. furthermore, this monolithic solution simplifies design, manufacturing and boosts performance of instrumentation by maintaining tight match of internal resistors and amplifiers. the AD8250s user interface comprises of a parallel port that allows users to set the gain in one of three different ways. a two bit word sent to a1 and a2, via a bus may be latched using the wr input. an alternative is to set the gain within 1 s by using the gain port in transparent mode where the state of a0 and a1 directly set the gain. the last method is to strap a1 and a2 to a high or low voltage potential, permanently setting the gain. the AD8250 is available in a 10 pin msop package and specified over -40 c to 85 c, making it an excellent solution for applications where size and packing density are 4 .com u datasheet
AD8250 preliminary technical data rev. prb | page 2 of 8 important considerations. table of contents AD8250?specifications.................................................................. 3 timing diagram ........................................................................... 5 absolute maximum ratings............................................................ 6 pin configurations and functional descriptions ....................... 7 transparent gain setting mode: .................................................7 write enable gain setting mode:................................................7 outline dimensions ..........................................................................8 esd caution...................................................................................8 revision history preliminary revision : b 4 .com u datasheet
preliminary technical data AD8250 rev. prb| page 3 of 8 AD8250?specifications table 1. v s = 12 v, v ref = 0 v (@t a = 25 o c, g = +1, r l = 2 k, unless otherwise noted.) AD8250arm parameter conditions min typ max unit common-mode rejection ratio (cmrr) cmrr to 60 hz with 1 k 4 .com u datasheet
AD8250 preliminary technical data rev. prb | page 4 of 8 AD8250arm parameter conditions min typ max unit average tc pa/ || || || || 4 .com u datasheet
preliminary technical data AD8250 rev. prb| page 5 of 8 AD8250arm parameter conditions min typ max unit output r l = 10 k 4 .com u datasheet
AD8250 preliminary technical data rev. prb | page 6 of 8 absolute maximum ratings table 2. AD8250 absolute maximum ratings parameter rating supply voltage +/-14v power dissipation see figure 2 output short circuit current common-mode input voltage -vs ? 0.5 v to +vs + 0.5 v differential input voltage v storage temperature ?65c to +125c operating temperature range ?40c to +85c lead temperature range (soldering 10 sec) c junction temperature c ja (4 layer jedec standard c/w board) package glass transition temperature c esd (human body model) kv esd (charge device model) kv esd (machine model) kv 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 condition s 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. 4 .com u datasheet
preliminary technical data AD8250 rev. prb| page 7 of 8 pin configurations and functional descriptions AD8250 top view (not to scale) -in 1 dgnd 2 -vs 3 a0 4 a1 5 +in vref +vs vout wr 10 9 8 7 6 figure 4. 10-lead msop table 3. pin function descriptions? 10-lead msop(arm package) pin no. name description 1 -in inverting input terminal (true differential input) 2 dgnd digital ground. 3 -vs negative supply terminal 4 a0 gain setting pin (lsb) 5 a1 gain setting pin (msb) 6 wr write enable 7 vout output terminal 8 +vs positive supply terminal 9 vref reference voltage terminal (drive this pin with a low impedance voltage source to level shif t the output signal) 10 +in non-inverting input terminal (true differential input) gain setting the AD8250?s gains are set digitally. the a0 and a1 pins must be set either high or low with respect to digital ground, dgnd. the wr pin is a tri-state switch. it may be set to one of three levels, high, low or to ?vs. a high signal is typically greater than 4v but less than 6v and a low signal is typically less than 1v but higher than dgnd, 0v. gains can be programmed using the following methods: transparent gain setting mode: in this mode, the gain is set by toggling a0 and a1 to high or low. to enable transparent mode, tie wr to ?vs. this configures the AD8250 to change gains when a0 and a1 are set according to table 4. table 4. . transparent mode gain settings g wr a1 a0 1 -vs lo lo 2 -vs lo hi 5 -vs hi lo 10 -vs hi hi write enable gain setting mode: in this mode, the gains are changed only during the negative edge of the wr strobe. so for instance, the gain is determined by the two bit value held on a0 and a1 at the time the wr strobe transitions from high to low. t wr-lo t wr-hi t su t hd wr a0, a1 table 5. : write enable mode gain settings gain (changes to) wr a1 a0 1 hi -> lo lo lo 2 hi -> lo lo hi 5 hi -> lo hi lo 10 hi -> lo hi hi no change lo->lo x x no change lo->hi x x no change hi-> hi x x x = don?t care . 4 .com u datasheet
AD8250 preliminary technical data rev. prb | page 8 of 8 outline dimensions compliant to jedec standards mo-187-ba 0.23 0.08 0.80 0.60 0.40 8 0 0.15 0.05 0.33 0.17 0.95 0.85 0.75 seating plane 1.10 max 10 6 5 1 0.50 bsc pin 1 coplanarity 0.10 3.10 3.00 2.90 3.10 3.00 2.90 5.15 4.90 4.65 figure 5. 10 lead msop (rm) ? dimensions shown in millimeters esd caution esd (electrostatic discharge) sensitive device. electrosta tic charges as high as 4000 v readily accumulate on the human body and test equipment and can discharge with out detection. although this product features proprietary esd protection circuitry, permanent dama ge may occur on devices subjected to high energy electrostatic discharges. therefore, proper esd precautions are recommended to avoid performance degradation or loss of functionality. table 6. ordering guide ad00000 products temperature package packag e description package option branding AD8250arz ?40c to +85c 10-lead msop rm-10 AD8250arz-rl ?40c to +85c 10-lead msop rm-10 AD8250arz-r7 ?40c to +85c 10-lead msop rm-10 AD8250-eval evaluation board 4 .com u datasheet
|
