-.. analog w devices 3 digit dpm module ad2023 features third generation 12 l lsi design multiplexed seven segment output version character serial bcd output version balanced differential input low power: +5v@0.1 watts (converter only) small size 2" x 2" x 0.4" (51x51x10.2mm) wide operating temperature range to extremes of -40c and +100 c available upon special request low cost: ad2023 - $39/1-9, $28/100s ad2023/b - $37/1-9, $27/100s applications led, lcd, beckman, etc. display, digital panel meters (dpms), particularly where available front panel meters prohibits use of traditional dpms. adc requirements general description the ad2023 is a low cost, 3 digit dpm module containing all the circuitry, except gain adjust pot, to drive three external display digits. the ad2023, with seven segment output, and the ad2023/b, with character serial bcd output, enable the user to drive any type of digital display. packaged in a small 2" x 2" x 0.4" module and requiring only +5v power, the ad2023 and ad2023/b address dpm needs where available front panel space is limited. the module, utilizing an 12 l lsi design, minimizes component count. most of the analog and digital circuitry is implemented on a single proprietory chip. the design is similar to and is based on the same 12l device as the highly successful ad2026 dpm. and all of the high ad2026 standards for quality and reliability are retained. ad2023 (with seven segment output) the ad2023 can drive a 3 digit led (light emitting diode) display. except for the display which is wired directly to the segment output pins of the module and a gain pot, all the cir- cuitry is self contained (an optional offset pot can also be used if desired). the ad2023 drives any size and type of currently available led display (for application assistance see page 3, figure 3). ad2023/b (with bcd output) with appropriate decoder driver, the ad2023/b character serial bcd output unit can drive a variety of different dis- plays. . . ie., led, lcd, beckman, etc. . only decoder driver, gain adjust pot, display and digit drivers when necessary are needed to complete the dpm. 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 implica- tion or otherwise under any patent or patent rights of analog devices. excellent performance the ad2023 measures inputs from -99mv to +999mv with an an accuracy of 0.1% of reading:!:1 digit. zero shift is :!:0.5mv over the full operating temperature range, resulting in the same performance as a dpm with auto zero. the balanced differen- tial input rejects common mode voltages up to 200mv, enough to eliminate most ground loop problems. automatic polarity indication is provided by using the msd (most significant digit) to indicate negative inputs. with the ad2023, automatic overrange indication for inputs greater than +999mv is displayed as j j j and for inputs less than -99mv, as - - -. the ad2023/b overload indication is bcd output code 1011 for all digits for inputs greater than +999mv and 1010 for all digits for inputs less than -99mv. wide temperature range wide temperature range modules, for extreme environment applications, are available up~n special re~uest. operating temperature extremes of -40 c and + 100 c and storage tem- perature of -55c and +125c allow the user to apply the ad2023 in environments where conventional dpms cannot be used. wide temperature range displays are also currently available from several v~ndors. (for further information con- sult factory.) route 1 industrial park; p.o. box 280; norwood, mass. 02062 tel: 617/329-4700 twx: 716/394-6577 west coast mid-west texas 213/595-1783 312/894-3300 214/231-5094 obsolete
specifications (typical @ +25c and +5v dc unless otherwise noted) conversion rate . normal: 4 conversions per second . high speed (h.s.): 48 to 168 conversion per second control inputs . hold (1 lsttl load). logic "0" or grounding disables internal or ef'ternal trigger and last conversion is held. logic "i" allows for normal operation. . high speed: logic "0" on the hold pin (18) and connec- ting the h.s. pin (20) to +5v, the module will convert 48 to 168 times per second. . lamp test - logic "0" on the lamp test pin (15) will turn all segments on in the positive range only. analog input . configuration: limited bipolar, balanced differential input. . full scale input range: -99mv to +999mv . automatic polarity . input impedance: 100mil . bias current: 1l0na . over voltage protection: :!:15v (inputs to ground) ad2023 display outputs . display current: 46ma/segment multiplexed . positive overload indication: j j j . negative range overload indication: - -- . digit select outputs: supply voltage, 5.5v (max) lout' 480ma (max pk) ad2023/b data/displa y outputs . negative indication: bcd code 1010 during msd . positive overload indication: bcd code 1011 for all digits . negative overload indication: bcd code 1010 for all digits . output loading: iol = 8ma @ vout ~0.5v iol = -40011a @ vout ;;. 2.7v . digit select outputs: supply voltage, 5.5v (max) lout' 100ma (max pk) accuracy . 0.1% reading:tl digit . resolution: imv . linearity: :tl bit . temperature rangel: -10c to +70oc operating -55c to +125c storage . temperature coefficient: gain: 50ppm/c . zero: 1011v/c (essentially auto zero) . warm up time to rated accuracy: instantaneous . settling time to rated accuracy: 0.3 second for full input voltage swing . input offset voltage: :to.3mv (max) common mode rejection (ik.q source imbalance, dc to 1khz) .50db common mode voltage . :t200m v gain adjust . a 5k multiturn pot connected from the gain pin (22) to ground provides the full scale adjustment. this pot is user supplied. external zero adjust (optional) . a 10kil pot across the zero terminals and the center arm to +5v the user can externally adjust zero offset. power input . converter: +5v :t5%, 0.1 watts typ.; 0.16 watts max . display: +4.75v to +5.5v @ 1.3 watts typ size . module 2" x 2" x 0.4" (51 x 51 x 10.2mm) weight . 1 ounce (28.4 grams) ordering guide . ad2023: multiplexed seven segment output . ad2023/b: character serial bcd output . ac2623: mounting card with gain and zero adjusts . ac2625: mounting card with gain and zero adjusts and three \12" high leds price . ad2023 . ad2023/b . ac2623 . ac2625 $39/1-9 $37/1-9 $34 $39 $28/100s $27/100s 1 guaranteed specifications subject to change without notice. outline dimensions and pin configurations dimensions shown in inches and (mm). notes: ,. pins 10, ". 12 and 15 not on model ad2023/b 1--2.0151) 1 .i ~ ~ 0.4 110.2) 0.o19d- - . 10.5) m see note ,-- - 1 0.2015.1\ 0.2516.1) 2.0 151) a 02023 ao2023/b 1 disp. power 2 msd 3 nsd 4 lsd 5 disp. gnd 6 a } 7 b 8 c segment 9 d outputs 10 e 11 f 12 g pin 22 ref pin 1 ref bottom view --ii-- 0.1 grid typ 12.5) 22 gain adjust 21 zero adjust 20 h. s. 19 zero adjust 18 hold 17 analog hi 16 analog lo 15 lamp test 14 cony. power 13 cony. gnd 1 disp. power 2 msd 3 nsd 4 lsd 5 dlsp.gnd 6 a } 7 b bcd 8 c outputs 9 d 22 gain adjust 21 zero adjust 20 h. s. 19 zero adjust 18 hold 17 analog hi 16 analog lo 14 cony. power 13 cony. gnd -2- --- obsolete
applying the ad2023 high speed (h.si(2 ad202j decoder driver dr ad202j!b bcd drivers figure 1. block diagram mounting cards to make ad2023 evaluation easy, two accessory mounting cards are available. both are 4y2"x4" (114.3x101.6mm) printed circuit cards. one comes equipped with gain and zero adjust pots and is suitable for use with the ad2023 or ad2023/b. the other also includes y2" high led display and is used with the ad2023. 3.4 square inches of breadboarding area is also provided on the two accessory cards. interconnect is via standard 44 pin card edge connector. applying the ad2023 description of operation the ad2023 and ad2023/b block diagram is shown in fig- ure 1. the two versions are functionally identic.al except at the data output section. in the ad2023 the 4 bcd lines from the 12 l chip are fed into a decoder driver and presented on pins 6 through 12 in seven segment output form for use with led displays. the bcd lines in the ad2023/b model are pro- cessed through bcd drivers and are presented on pins 6 through 9 in a character serial bcd format. signal input, user supplied gain adjust and optional zero ad- just connections are applied directly to the chip. hold, high speed conversion and lamp test are implemented via control logic circuitry. most of the analog to digital conversion takes place within the chip which feeds character serial data to a seven segment decoder driver (ad2023) or bcd line drivers (ad2023/b). the appropriate digit is identified via three digit select lines. msd nsd lsd hold >5m, ~ 'conversion takes place here note: overlap may occur between digits figure 2. timing diagram 3j msd i) ~6~~~y "2 seven segment output ao202j only the timing diagram, figure 2, shows that the hold input may be used as a psuedo-trigger provided the trigger pulse is >sms (insures at least 1 conversion). a conversion can only be ini- tiated when all three digit lines are low and the hold line is high. as shown, the sequence of digits is msd, lsd, and nsd. led dispaly dpm the total requirement to construct a led display dpm using the ad2023 is shown in figure 3. ana hi { a ana lo b seven c segment 0 output e f ao2023 g g { a digit msd i select nsd n lsd optional current limiting resistors for brightness adjustments / , l i digit 1 msd digit 2 nsd digit 3 lsd figure 3. ad2023 with led interface lcd display dpm construction of lcd display dpm requires only an ad2023, lcd driver and the lcds. ana hi { a ana lo bcd b ou~~~ c 0 ad2023/b ~ msd g digit nsd ~ select lsd n +vs -3- figure 4. ad2023/b with lcd interface obsolete
beckman display dpm if a beckman gas discharge display is desired added compo- nents are: three displays, one dd700 decoder driver and three high voltage anode drivers. +5v ana hi { a bcd ana lo data b output c d ad2023/b msd nsd lsd high voltage anode drivers figure 5. ad2023/b with beckman interface bcd output dpm in some cases the ad2023/b may be the choice even when led display is to be used. this permits the ad2023/b bcd output to drive other devices as well as the display and display can be used to show converted data directly and/or processed data. figure 6 shows a bcd output dpm with led displays. it is possible to obtain bcd outputs in this fashion when using other displays as well. figure 6. ad2023/b with led/pp interface input wiring connections i, bias 17 -<> hi ad2023 16 .0- lo 13 14 +5v e r?i00kn) common mode figure 7. connect to ad2023 as per above for balanced differential input as shown. the common mode loop must provide a return path for bias currents (11 bias, 12 bias) internal to the ad2023. the resistance (r) of this path must be less than 100kil. caution: total common mode voltage between pins 13 and 16 must not exceed 200mv. for single ended input, connect pin 13 to pin 16. accessory cards as shown in figures 8 and 9, two cards are available, the ac2623 with gain and zero pots and the ac2625 with gain pot, zero pot and three seven segment led displays. both versions come complete with solder pads, power buss tracks and other features to allow for easy breadboarding. right angle connectors for mounting leds perpendicular to the p.c. board are available and accessory card is laid out to be able to receive these connectors. connectors are availabe from augat 6x51-73-161 and aries electronics 34-6823-90. i' i' en i 00 i n n ' |
