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max174/mx574a/MX674A industry-standard, complete 12-bit adcs ????????????????????????????????????????????????????????????????? maxim integrated products 1 functional diagram 19-2765; rev 3; 8/11 ordering information appears at end of data sheet. for related parts and recommended products to use with this part, refer to www.maxim-ic.com/max174.related . evaluation kit available general description the max174/mx574a/MX674A are complete 12-bit analog-to-digital converters (adcs) that combine high speed, low-power consumption, and on-chip clock and voltage reference. the maximum conversion times are 8s (max174), 15s (MX674A), and 25s (mx574a). maxims bicmos construction reduces power dissipa - tion 3 times (150mw) over comparable devices. the internal buried zener reference provides low-drift and low-noise performance. external component require - ments are limited to only decoupling capacitors and fixed resistors. the versatile analog input structure allows for 0 to +10v or 0 to +20v unipolar or 5v or 10v bipolar input ranges with pin strapping. the max174/mx574a/MX674A use standard micropro - cessor interface architectures and can be interfaced to 8-, 12-, and 16-bit wide buses. three-state data outputs are controlled by cs , ce, and r/ c logic inputs. features s complete adc with reference and clock s 12-bit resolution and linearity s no missing codes over temperature s 150mw power dissipation s 8s (max174), 15s (MX674A), and 25s (mx574a) max conversion times s precision low tc reference: 10ppm/ n c s monolithic bicmos construction s 150ns maximum data access time applications digital signal processing high-accuracy process control high-speed data acquisition electro-mechanical systems r 14 5ki 9.950ki 5ki 13 12 11 v ee bipoff 10v in 20v in 2r +10v ref 9 8 10 refin agnd refout 12-bit dac 7 v cc 15 dgnd 1 v l sar 12 low nibble 44 4 middle nibble high nibble clock and control logic 2 12/8 a0 3 4 27 5 6 28 24 23 20 19 16 d0 d3 d4 d7 d8 d11 sts ce r/ c cs max174 mx574a MX674A for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxims website at www.maxim-ic.com.
????????????????????????????????????????????????????????????????? maxim integrated products 2 max174/mx574a/MX674A industry-standard, complete 12-bit adcs v cc to dgnd .............................................................. 0 to 16.5v v ee to dgnd ............................................................... 0 to 16.5v v l to dgnd ...................................................................... 0 to 7v dgnd to agnd ................................................................... q 1v control inputs to dgnd (ce, cs , a0, 12/ 8 , r/ c ) ........................ -0.3v to (v cc + 0.3v) digital output voltage to dgnd (db11Cdb0, sts) ..................................... -0.3v to (v l + 0.3v) analog inputs to agnd (refin, bipoff, 10v in ) ........... q 16.5v 20v in to agnd ................................................................... q 24v refout ................................... indefinite short to v cc or agnd power dissipation (any package) to +75 n c ................. 1000mw derates above +75 n c .............................................. 10mw/ n c operating temperature ranges max174_c, mx_74aj/k/l ...................................... 0 to +70 n c max174_e, mx_74aje/ke/le ........................ -40 n c to +85 n c max174_m, mx_74as/t/u ............................ -55 n c to +125 n c storage temperature range ............................ -55 n c to +160 n c lead temperature (soldering, 10s) ................................ +300 n c soldering temperature (reflow) pdip, wide so ............................................................. +260 n c plcc ............................................................................ +245 n c absolute maximum ratings stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. these are stress ratings only, and functional opera - tion 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 characteristicsmax174 (v l = +5v, v ee = +15v or +12v, v ee = -15v or -12v, t a = +25 n c, unless otherwise noted.) parameter symbol conditions min typ max units accuracy resolution res 12 bits integral nonlinearity inl t a = +25c max174a/b 1/2 lsb max174c 1 t a = t min to t max max174ac/bc 1/2 max174ae/be/am/bm 3/4 max174c 1 differential nonlinearity dnl 12 bits, no missing codes over temperature 1 lsb unipolar offset error (note 1) max174a/b 1 lsb max174c 2 bipolar offset error (notes 2, 3) max174a 3 lsb max174b/c 4 full-scale calibration error (note 3) 0.25 % temperature coefficients (using internal reference) (notes 2, 3, 4) unipolar offset change max174a/b 1 lsb max174c 2 bipolar offset change max174ac/bc 1 lsb max174cc 2 max174ae/am 1 max174be/bm 2 max174ce/cm 4
????????????????????????????????????????????????????????????????? maxim integrated products 3 max174/mx574a/MX674A industry-standard, complete 12-bit adcs electrical characteristicsmx574a, MX674A (v l = + 5v, v ee = +15v or +12v, v ee = -15v or -12v, t a = +25 n c, unless otherwise noted.) electrical characteristicsmax174 (continued) (v l = +5v, v ee = +15v or +12v, v ee = -15v or -12v, t a = +25 n c, unless otherwise noted.) parameter symbol conditions min typ max units accuracy resolution res 12 bits integral nonlinearity inl t a = +25c mx574ak/l/t/u, MX674Ak/l/t/u 1/2 lsb mx574aj/s, MX674Aj/s 1 t a = t min to t max mx574ak/l/ke/le 1/2 MX674Ak/l/ke/le 1/2 mx574at/u, MX674At/u 3/4 mx574aj/s, MX674Aj/s 1 differential nonlinearity dnl 12 bits, no missing codes over temperature 1 lsb unipolar offset error (note 1) mx574ak/l/t/u, MX674Ak/l/t/u 1 lsb mx574aj/s, MX674Aj/s 2 bipolar offset error (notes 2, 3) mx574al/u, MX674Al/u 3 lsb mx574aj/k/s/t, MX674Aj/k/s/t 4 full-scale calibration error (note 3) mx574al/u 0.125 % mx574aj/k/s/t, MX674A 0.25 temperature coefficients (using internal reference) (notes 2, 3, 4) unipolar offset change mx574ak/l/t/u, MX674Ak/l/t/u 1 lsb mx574aj/s, MX674Aj/s 2 parameter symbol conditions min typ max units full-scale calibration change max174ac 2 (10) lsb (ppm/c max174bc 5 (27) max174cc 9 (50) max174ae 7 (19) max174be 10 (38) max174ce 20 (75) max174am 5 (12) max174bm 10 (25) max174cm 20 (50) internal reference output voltage no load max174a 9.98 10.00 10.02 v max174b/c 9.97 10.00 10.03 output current (note 5) available for external loads, in addition to refin and bipoff load 2 ma
????????????????????????????????????????????????????????????????? maxim integrated products 4 max174/mx574a/MX674A industry-standard, complete 12-bit adcs electrical characteristicsmx574a, MX674A (continued) (v l = + 5v, v ee = +15v or +12v, v ee = -15v or -12v, t a = +25 n c, unless otherwise noted.) electrical characteristicsmax174/mx574/MX674A (v l = +5v, v cc = +15v or +12v, v ee = -15v or -12v, t a = +25 n c, unless otherwise noted.) parameter symbol conditions min typ max units bipolar offset change mx574ak/l, MX674Ak/l 1 lsb mx574aj, MX674Aj 2 mx574au/le, MX674Au/le 1 mx574at/ke, MX674At/ke 2 mx574as/je, MX674As/je 4 full-scale calibration change mx574al, MX674Al 2 (10) lsb (ppm/c mx574ak, MX674Ak 5 (27) mx574aj, MX674Aj 9 (50) mx574ale, MX674Ale 7 (19) mx574ake, MX674Ake 10 (38) mx574aje, MX674Aje 20 (75) mx574au, MX674Au 5 (12) mx574at, MX674At 10 (25) mx574as, MX674As 20 (50) internal reference output voltage no load mx574al/u 9.99 10.00 10.01 v mx574aj/k/s/t, MX674Al/u 9.98 10.00 10.02 MX674Aj/k/s/t 9.97 10.00 10.03 output current (note 5) available for external loads, in addition to refin and bipoff load 2 ma parameter symbol conditions min typ max units analog input bipolar input range using 10v input 5 v using 20v input 10 unipolar input range using 10v input 0 +10 v using 20v input 0 +20 input impedance 10v input 3 5 7 k w 20v input 6 10 14 power-supply rejection (max change in full-scale calibration) v cc only 15v 1.5v or 12v 0.6v max174a/b, mx_74ak/l/tu 1/8 1 lsb max174c, mx_74aj/s 1/8 2 v ee only 15v 1.5v or 12v 0.6v 1/8 1/2 lsb v l only 5v 0.5v 1/8 1/2 lsb logic inputs input low voltage v il cs , ce, r/ c , a0, 12/ 8 0.8 v input high voltage v ih cs , ce, r/ c , a0, 12/ 8 2.0 v
????????????????????????????????????????????????????????????????? maxim integrated products 5 max174/mx574a/MX674A industry-standard, complete 12-bit adcs note 1: adjustable to zero. note 2: with 50 fixed resistor from refout to bipoff. adjustable to zero. note 3: with 50 fixed resistor from refout to refin. adjustable to zero. note 4: maximum change in specification from t a = +25c to t min or t a = +25c to t max . note 5: external load current should not change during a conversion. for q 12v supply operation, refout need not be buffered except when external load in addition to refin and bipoff inputs have to be driven. electrical characteristicsmax174/mx574/MX674A (continued) (v l = +5v, v cc = +15v or +12v, v ee = -15v or -12v, t a = +25 n c, unless otherwise noted.) parameter symbol conditions min typ max units input current i in cs , ce, r/ c , a0, 12/ 8 , v in = 0 to v l 5 a input capacitance c in cs , ce, r/ c , a0, 12/ 8 7 pf logic outputs output low voltage v ol db11Cdb0, sts i sink = 1.6ma 0.4 v output high voltage v oh db11Cdb0, sts i source = 500a 4 v floating state leakage current i lkg db11Cdb0, sts v out = 0 to v l 10 a floating state output capacitance c out db11Cdb0 8 pf conversion time 12-bit cycle t conv mx574a 15 20 25 s MX674A 9 12 15 max174 6 7 8 8-bit cycle t conv mx574a 10 14 18 s MX674A 6 8 11 max174 4 5 6 power requirements v cc operating range 11.4 16.5 v v l operating range 4.5 5.5 v v ee operating range -11.4 -16.5 v v cc supply current (note 5) i cc 3 5 ma v l supply current (note 5) i l 3 8 ma v ee supply current (note 5) i ee 6 10 ma power dissipation (note 5) p d v cc = +15v and v ee = -15v 150 265 mw
????????????????????????????????????????????????????????????????? maxim integrated products 6 max174/mx574a/MX674A industry-standard, complete 12-bit adcs note 6: timing specifications guaranteed by design. all input control signals specified with t r = t f = 5ns (10% to 90% of +5v) and timed from a voltage level of +1.6v. see loading circuits in figures 1 and 2. timing characteristicsmax174/mx574a/MX674A (v l = +5v, v cc = +15v or +12v, v ee = -15v or -12v.) (note 6) parameter symbol conditions t a = +25c t a = -40c to +85c t a = 0c to +70 c t a = -55c to +125c units min typ max min typ max min typ max convert start timingfull control mode sts delay from ce t dsc c l = 50pf 100 200 250 320 ns ce pulse width t hec 50 15 50 50 ns cs to ce setup t ssc 50 50 50 ns cs low during ce high t hsc 50 50 50 ns r/ c to ce setup t src 50 50 50 ns r/ c low during ce high t hrc 50 50 50 ns a0 to ce setup t sac 0 0 0 ns a0 valid during ce high t hac 50 50 50 ns read timingfull control mode access time (from ce) t dd c l = 100pf 60 120 150 200 ns data valid after ce low t hd 25 40 20 15 ns output float delay t hl 75 100 120 ns cs to ce setup t ssr 50 50 50 ns r/ c to ce setup t srr 0 0 0 ns a0 to ce setup t sar 50 50 50 ns cs valid after ce low t hsr 0 0 0 ns r/ c high after ce low t hrr 0 0 0 ns a0 valid after ce low t har 0 0 0 ns stand-alone mode low r/ c pulse width t hrl 50 15 50 50 ns sts delay from r/ c t ds 115 200 250 320 ns data valid after r/ c low t hdr 25 40 20 15 ns sts delay after data valid t hs mx574a 300 600 1000 300 1000 300 1000 ns MX674A 30 320 600 30 600 30 600 max174 30 140 300 30 300 30 400 high r/ c pulse width t hrh 150 150 200 ns data access time t ddr c l = 100pf 60 120 150 200 ns
????????????????????????????????????????????????????????????????? maxim integrated products 7 max174/mx574a/MX674A industry-standard, complete 12-bit adcs figure 2. load circuit for output float delay test figure 1. load circuit for access time test pin configurations pin description pin name function 1 v l logic supply, +5v 2 12/ 8 data mode select input 3 cs chip-select input. must be low to select device. 4 a0 byte address/short-cycle input. when starting a conversion, controls number of bits converted (low = 12 bits, high = 8 bits). when reading data, if 12/ 8 = low, enables low byte (a0 = high) or high byte (a0 = low). 5 r/ c read/convert input. when high, the device will be in the data-read mode. when low, the device will be in the conversion start mode. 3ki dn 100pf high-z to logic 1 3ki +5v dn 100pf high-z to logic 1 3ki dn 100pf logic 1 to high - z 3ki +5v dn 100pf logic 0 to high - z 28 27 26 25 24 23 22 21 1 2 3 4 5 6 7 8 v l sts d11 d10 d9 d8 d7 d6 d5 top view ce a0 v cc refout 20 19 9 10 d4 d3 agnd refin 18 17 11 12 d2 d1 v ee bipoff 16 15 13 14 d0 dgnd 10v in 20v in max174 mx574a MX674A dip/so + 12 /8 r/ c cs 12 bipoff 10v in 20v in dgnd d0 d1 d2 a0 cs 12/ 8 v l sts d11 d10 d3 v ee d4 refin d5 agnd d6 refout d7 v cc d8 ce d9 r/ c 13 14 15 16 17 18 1 2 3 42 6 27 28 19 20 21 22 23 24 25 5 6 7 8 9 10 11 max174 mx574a MX674A plcc top view
????????????????????????????????????????????????????????????????? maxim integrated products 8 max174/mx574a/MX674A industry-standard, complete 12-bit adcs pin description (continued) detailed description converter operation the max174/mx574a/MX674A use a successive approx - imation technique to convert an unknown analog input to a 12-bit digital output code. the control logic provides easy interface to most microprocessors. most applica - tions require only a few external passive components to perform the analog-to-digital (a/d) function. the internal voltage output dac is controlled by a suc - cessive approximation register (sar) and has an output impedance of 2.5k. the analog input is connected to the dac output with a 5k resistor for the 10v input and 10k resistor for the 20v input. the comparator is essen - tially a zero-crossing detector, and its output is fed back to the sar input. the sar is set to half-scale as soon as a conversion starts. the analog input is compared to 1/2 of the full-scale volt - age. the bit is kept if the analog input is greater than half- scale or dropped if smaller. the next bit, bit 10, is then set with the dac output either at 1/4 scale, if the most signifi - cant bit (msb) is dropped, or 3/4 scale if the msb is kept. the conversion continues in this manner until the least significant bit (lsb) is tried. at the end of the conversion, the sar output is latched into the output buffers. digital interface ce, cs , and r/ c control the operation of the max174/ mx574a/MX674A. while both ce and cs are asserted, the state of r/ c selects whether a conversion (r/ c = 0) or a data read (r/ c = 1) is in progress. the register control inputs, 12/ 8 and a0, select the data format and conver - sion length. a0 is usually tied to the lsb of the address bus. to perform a full 12-bit conversion, set a0 low during a convert start. for a shorter 8-bit conversion, a0 must be high during a convert start. output data format during a data read, a0 also selects whether the three- state buffers contain the 8 msbs (a0 = 0) or the 4 lsbs (a0 = 1) of the digital result. the 4 lsbs are followed by 4 trailing 0s. output data is formatted according to the 12/ 8 pin. if this input is low, the output will be a word broken into two 8-bit bytes. this allows direct interlace to 8-bit buses without the need for external three-state buffers. if 12/ 8 is high, the output will be one 12-bit word. a0 can change state while a data-read operation is in effect. to begin a conversion, the microprocessor must write to the adc address. then, since a conversion usually takes longer than a single clock cycle, the microproces - sor must wait for the adc to complete the conversion. valid data will be made available only at the end of the conversion, which is indicated by sts. sts can be ether polled or used to generate an interrupt upon completion. or, the microprocessor can be kept idle by inserting the appropriate number of no operation (nop) instructions between the conversion-start and data-read commands. pin name function 6 ce chip-enable input. must be high to select device. 7 v cc +12v or +15v supply 8 refout +10v reference output 9 agnd analog ground 10 refin reference input 11 v ee -12v or -15v supply 12 bipoff bipolar offset input. connect to refout for bipolar input range. 13 10v in 10v span input 14 20v in 20v span input 15 dgnd digital ground 16C27 d0Cd11 three-state data outputs 28 sts status output
????????????????????????????????????????????????????????????????? maxim integrated products 9 max174/mx574a/MX674A industry-standard, complete 12-bit adcs table 1. truth table after the conversion is completed, data can be obtained by the microprocessor. the adcs have the required logic for 8-, 12-, and 16-bit bus interfacing, which is determined by the 12/ 8 input. if 12/ 8 is high, the adcs are configured for a 16-bit bus. data lines d0Cd11 may be connected to the bus as either the 12 msbs or the 12 lsbs. the other 4 bits must be masked out in software. for 8-bit bus operation, 12/ 8 is set low. the format is left justified, and the even address, a0 low, contains the 8 msbs. the odd address, a0 high, contains the 4 lsbs, which is followed by 4 trailing 0s. there is no need to use a software mask when the adcs are connected to an 8-bit bus. note that the output cannot be forced to a right-justified for - mat by rearranging the data lines on the 8-bit bus interface. figure 3. analog equivalent circuit table 2. max174/mx574a/MX674A data format for 8-bit bus ce cs r/ c 12/ 8 a0 operation 0 x x x x none x 1 x x x none 1 0 0 x 0 initiate 12-bit conversion 1 0 0 x 1 initiate 12-bit conversion 1 0 1 1 x enable 12-bit conversion 1 0 1 0 0 enable 8 msbs 1 0 1 0 1 enable 4 lsbs + 4 trailing 0s d7 d6 d5 d4 d3 d2 d1 d0 high byte (a0 = 0) msb d10 d9 d8 d7 d6 d5 d4 low byte (a0 = 1) d3 d2 d1 d0 0 0 0 0 r* 2r* -50i 5ki 9.950ki 5ki 1.6ki bipoff 10v in 20v in refin sar 2.5ki dac refin 2 27 (msb) 26 (d10) 25 (d9) 24 (d8) 23 (d7) 22 (d6) 21 (d5) 20 (d4) 19 (d3) 18 (d2) 17 (d1) 16 (lsb) hardwiring for 8-bit data buses d7 d6 d5 d4 d3 d2 d1 d0 data bus max174 mx574a MX674A
???????????????????????????????????????????????????????????????? maxim integrated products 10 max174/mx574a/MX674A industry-standard, complete 12-bit adcs figure 4. convert start timing figure 5. read timing timing and control convert start timingfull control mode r/ c must be low before asserting both ce and cs . if it is high, a brief read operation occurs possibly resulting in system bus contention. to initiate a conversion, use either ce or cs . ce is recommended since it is shorter by one propagation delay than cs and is the faster input of the two. ce is used to begin the conversion in figure 4 . the sts output is high during the conversion indicating the adc is busy. during this period, additional convert start commands will be ignored, so that the conversion cannot be prematurely terminated or restarted. however, if the state of a0 is changed after the beginning of the conversion, any additional start conversion transitions will latch the new state of a0, possibly resulting in an incorrect conversion length (8 bits vs. 12 bits) for that conversion. read timingfull control mode figure 5 illustrates the read-cycle timing. while reading data, access time is measured from when ce and r/ c are both high. access time is extended 10ns if cs is used to initiate a read. t hsc t hec ce a0 sts d0?d11 t ssc t hrc t src t hac t dsc t c t sac high impedance r/ c cs t ssr t srr t sar t har t hrr t hsr high impedance t dd t hd, t hl ce a0 sts d0?d11 r/ c cs
???????????????????????????????????????????????????????????????? maxim integrated products 11 max174/mx574a/MX674A industry-standard, complete 12-bit adcs figure 6. low pulse for r//c in stand-alone mode figure 7. high pulse for r//c in stand-alone mode figure 8. power-supply grounding practice stand-alone operation for systems which do not use or require full bus interfac - ing, the max174/mx574a/MX674A can be operated in a stand-alone mode directly linked through dedicated input ports. when configured in the stand-alone mode, conversion is controlled by r/ c . in addition, cs and a0 are wired low; ce and 12/ 8 are wired high. to enable the three-state buffers, set r/ c low. a conversion starts when r/ c is set high. this allows either a high- or a low-pulse control sig - nal. shown in figure 6 is the operation with a low pulse. in this mode, the outputs, in response to the falling edge of r/ c , are forced into the high-impedance state and return to valid logic-levels after the conversion is complete. the sts output goes high following the r/ c falling edge and returns low when the conversion is complete. a high-pulse conversion initiation is illustrated in figure 7 . when r/ c is high, the data lines are enabled. the next con - version starts with the falling edge of r/ c . the data lines return and remain in high impedance state until another r/ c high pulse. analog considerations application hints physical layout for best system performance, pcbs should be used for the max174/mx574a/MX674A. wire wrap boards are not recommended. the layout of the board should ensure that digital and analog signal lines are kept separated from each other as much as possible. care should be taken not to run analog and digital lines parallel to each other or digital lines underneath the max174/mx574a/ MX674A. grounding the recommended power-supply grounding practice is shown in figure 8 . the ground reference point for the on- chip reference is agnd. it should be connected directly to the analog reference point of the system. the analog and digital grounds should be connected together at the package in order to gain all of the accuracy possible from the max174/mx574a/MX674A in high digital noise environments. in situations permitting, they can be con - nected to the most accessible ground-reference point. the preference is analog power return. t hdr t hs t ds t hrl t c r/ c sts d0?11 high impedance t hrh t ds r/ c sts d0?11 t ddr t hdr high impedance s/ h and analog circuitry digital circuitry v ee gndv cc v ee agnd dgnd dgnd +5v v l v cc max174 mx574a MX674A analog supply digital supply -15v gnd +15v +5v gnd
???????????????????????????????????????????????????????????????? maxim integrated products 12 max174/mx574a/MX674A industry-standard, complete 12-bit adcs figure 9. power-supply bypassing power-supply bypassing the max174/mx574a/MX674A power supplies must be filtered, well regulated, and free from high-frequency noise, or unstable output codes will result. unless great care is taken in filtering any switching spikes present in the output, switching power supplies is not suggested for applications requiring 12-bit resolution. take note that a few millivolts of noise converts to several error counts in a 12-bit adc. all power-supply pins should use supply decoupling capac - itors connected with short lead length to the pins, as shown in figure 9 . the v cc and v ee pins should be decoupled directly to agnd. a 4.7f tantalum type in parallel with a 0 1f disc ceramic type is a suitable decoupling. internal reference the max174/mx574a/MX674A have an internal buried zener reference that provides a 10v, low-noise and low - temperature drift output. an external reference voltage can also be used for the adc. when using 15v sup - plies, the internal reference can source up to 2ma in addition to the bipoff and refin inputs over the entire operating temperature range. with 12v supplies, the reference can drive the bipoff and refin inputs over temperature, but it cannot drive an additional load. driving the analog input the input leads to agnd and 10v in or 20v in should be as short as possible to minimize noise pick up. if long leads are needed, use shielded cables. when using the 20v in as the analog input, load capaci - tance on the 10v in pin must be minimized. especially on the faster max174, leave the 10v in pin open to minimize capacitance and to prevent linearity errors caused by inadequate settling time. the amplifier driving the analog input must have low enough dc output impedance for low full-scale error. furthermore, low ac output impedance is also required since the analog input current is modulated at the clock rate during the conversion. the output impedance of an amplifier is the open-loop output impedance divided by the loop gain at the frequency of interest. mx574a and MX674Athe approximate internal clock rate is 600khz and 1mhz, respectively, and amplifiers like the max400 can be used to drive the input. max174the internal clock rate is 2mhz and faster amplifiers like the op-27, ad711, or op-42 are required. track-and-hold interface the analog input to the adc must be stable to within 1/2 lsb during the entire conversion for specified 12-bit accuracy. this limits the input signal bandwidth to a couple of hertz for sinusoidal inputs even with the faster max174. for higher bandwidth signals, a track-and-hold amplifier should be used. the sts output may be used to provide the hold signal to the track-and-hold amplifier. however, since the a/ds dac is switched at approximately the same time as the conversion is initiated, the switching transients at the out - put of the t/h caused by the dac switching may result in code dependent errors. it is recommended that the hold signal to the t/h amplifier precede a conversion or be coincident with the conversion start. the first bit decision by the a/d is made approximately 1.5 clock cycles after the start of the conversion. this is 2.5s, 1.5s, and 0.8s for the mx574a, MX674A, and max174, respectively. the t/h hold settling time must be less than this time. for the mx574a and MX674A, the ad585 sample-and-hold is recommended ( figure 10 ). for the max174, a faster t/h amplifier, like the ha5320 or ha5330, should be used ( figure 11 ). input configurations the max174/mx574a/MX674A input range can be set using pin strapping. table 3 shows the possible input ranges and ideal transition voltages. end-point errors can be adjusted in all ranges. v l +5v digital ground analog ground +12v/ 15v -12v/ 15v v cc v ee dgnd recommended c 1 , c 2 , c 4 ? 0.1f ceramic c 4 , c 5 , c 6 ? 4.7f agnd max174 mx574a MX674A c 4 c 1 c 5 c 2 c 6 c 3
???????????????????????????????????????????????????????????????? maxim integrated products 13 max174/mx574a/MX674A industry-standard, complete 12-bit adcs table 3. input ranges and ideal digital output codes note 7: for unipolar input ranges, output coding is straight binary. note 8: for bipolar input ranges, output coding is offset binary. note 9: for 0 to + 10v or 5v ranges, 1 lsb = 2.44mv. note 10 : for 0 to +20v or 10v ranges, 1 lsb = 4.88mv. * the digital outputs will be flickering between the indicated code and the indicated code plus one. figure 10. mx574/MX674A to ad585 sample-and-hold interface analog input voltage (v) digital output 0 to +10v 0 to +20v 5v 10v msb lsb +10.0000 +20.0000 +5.0000 +10.0000 1111 1111 1111 +9.9963 +19.9927 +4.9963 +9.9927 1111 1111 1110* +5.0012 +10.0024 +0.0012 +0.0024 1000 0000 0000* +4.9988 +9.9976 -0.0012 -0.0024 0111 1111 1111* +4.9963 +9.9927 -0.0037 -0.0073 0111 1111 1110* +0.0012 +0.0024 -4.9988 -9.9976 0000 0000 0000* 0.0000 0.0000 -5.0000 -10.0000 0000 0000 0000 sts 20v in 10v in bipoff refout refin -v s v cc +v in *additional pins omitted for clarity gnd 0.1f analog input -15v 4.7f agnd dgnd hold lref vout -v in 50i 50i hold +15v 4.7f 0.1f v ee -15v 4.7f 0.1f v l +5v 4.7f 0.1f ad585* control inputs +v s +15v 4.7f 0.1f mx574a* MX674A d0 ?11
???????????????????????????????????????????????????????????????? maxim integrated products 14 max174/mx574a/MX674A industry-standard, complete 12-bit adcs figure 11. max174 to ha5320 sample-and-hold interface unipolar input operation the unipolar transfer function and input connections are shown in figures 12 and 13 . because all internal resistors of the max174/mx574a/ MX674A are trimmed for absolute calibration, additional trimming is not necessary for most applications. the absolute accuracy for each grade is given in the speci - fication tables. if the offset trim is not needed, bipoff can be tied direct - ly to agnd. the two resistors and trimmer for bipoff can then be discarded. a 50 1% metal film resistor should be attached between refout and refin. for a 0 to +10v input range, the analog input is con - nected between agnd and 10v in . for a 0 to +20v input range, the analog input is connected between agnd and 20v in . these adcs can easily handle an input signal beyond the supplies. if full-scale trim is not needed, the gain trimmer, r2, should be swapped with a 50 resis - tor. should a 10.24v input range be selected, a 200 trimmer should be inserted in series with 10v in . for a full- scale input range of 20.48v, use a 500 trimmer in series with 20v in . the nominal input impedance into 10v in is 5k and 10k for 20v in . offset and full-scale adjustment in applications where the offset and full-scale range have to be adjusted, use the circuit shown in figure 12 . the offset should be adjusted first. apply 1/2 lsb at the analog input and adjust r1 until the digital output code flickers between 0000 0000 0000 and 0000 0000 0001. to adjust the full-scale range, apply fs - 3/2 lsb at the analog input and adjust r2 until the output code changes between 1111 1111 1110 and 1111 1111 1111. bipolar input operation the bipolar transfer function is shown in figure 14 , and input connections are shown in figure 15 . one or both of the trimmers can be exchanged with a 50 1% fixed resistor if the offset and gain specifications suffice. offset and full-scale adjustment to begin bipolar calibration, a signal 1/2 lsb above neg - ative full-scale is applied. r1 is trimmed until the digital output flickers between 0000 0000 0000 and 0000 0000 0001. next, a signal 3/2 lsb below positive full scale is applied. then, r2 is trimmed until the output flickers between 1111 1111 1110 and 1111 1111 1111. sts 20v in 10v in bipoff refout refin -v s v cc +v in *additional pins omitted for clarity gnd 0.1f analog input -15v 4.7f agnd dgnd s/h vout -v in 50i 50i +15v 4.7f 0.1f v ee -15v 4.7f 0.1f v l +5v 4.7f 0.1f ha5320* control inputs +v s +15v 4.7f 0.1f max174* d0 ?11
???????????????????????????????????????????????????????????????? maxim integrated products 15 max174/mx574a/MX674A industry-standard, complete 12-bit adcs figure 13. unipolar input connections figure 12. ideal unipolar transfer function figure 15. bipolar input connections figure 14. ideal bipolar transfer function refout gain refin bipoff 10v in *additional pins omitted for clarity 100i 100ki +12v to +15v -12v to -15v 0 to +10v 0 to +20v analog inputs offset r 1 100ki r 2 100i 20v in agnd max174* mx574a MX674A refin gain refout bipoff 10v in *additional pins omitted for clarity q5v q10v analog inputs r 2 100i r 1 100i offset 20v in agnd max174* mx574a MX674A 0 output code 1111 1111 1111 1111 1111 1110 1111 1111 1101 0000 0000 0011 0000 0000 0010 0000 0000 0001 0000 0000 0000 12 3 fs-1 full-scale transition fs = 4069 lsbs fs output code 1111 1111 1111 1111 1111 1110 1111 1111 1101 1000 0000 0001 1000 0000 0000 0111 1111 1111 0111 1111 1110 0000 0000 0011 0000 0000 0010 0000 0000 0001 0000 0000 0000 analog input voltage in lsbs fs 2 - fs = 4069 lsbs fs 2 - +2 -2 -1 01 fs 2 2 fs 2 1 fs 2 fs 2 - +1
???????????????????????????????????????????????????????????????? maxim integrated products 16 max174/mx574a/MX674A industry-standard, complete 12-bit adcs ordering information +denotes a lead(pb)-free/rohs-compliant package. *maxim reserves the right to ship ceramic sb in lieu of cerdip packages. **consult factory for dice specifications. part pin- package linearity (lsb) tempco (ppm/ n c) 8s maximum conversion time temp range: 0 n c to +70 n c max174acpi+ 28 plastic dip ? 10 max174bcpi+ 28 plastic dip ? 27 max174ccpi+ 28 plastic dip 1 50 max174acwi+ 28 wide so ? 10 max174bcwi+ 28 wide so ? 27 max174ccwi+ 28 wide so 1 50 max174bc/d dice* 1/2 temp range: -40 n c to +85 n c max174aepi+ 28 plastic dip ? 19 max174bepi+ 28 plastic dip ? 38 max174cepi+ 28 plastic dip 1 75 max174aewi+ 28 wide so ? 19 max174bewi+ 28 wide so ? 38 max174cewi+ 28 wide so 1 75 temp range: -55 n c to +125 n c max174amji 28 cerdip ? 12 max174bmji 28 cerdip ? 25 max174cmj 28 cerdip 1/21 50 15s maximum conversion time temp range: 0 n c to +70 n c MX674Ajn+ 28 plastic dip 1 50 MX674Akn+ 28 plastic dip ? 27 MX674Aln+ 28 plastic dip ? 10 MX674Ajcwi+ 28 wide so 1 50 MX674Akcwi+ 28 wide so ? 27 MX674Alcwi+ 28 wide so ? 10 MX674Ak/d dice* ? temp range: -40 n c to +85 n c MX674Ajepi+ 28 plastic dip 1 75 MX674Akepi+ 28 plastic dip ? 38 MX674Alepi+ 28 plastic dip ? 19 MX674Ajewi+ 28 wide so 1 75 MX674Akewi+ 28 wide so ? 38 MX674Alewi+ 28 wide so ? 19 part pin- package linearity (lsb) tempco (ppm/ n c) temp range: -55 n c to +125 n c MX674Asq 28 cerdip* 1 50 MX674Atq 28 cerdip* ? 25 MX674Auq 28 cerdip* ? 12 MX674Asd 28 ceramic sb 1 50 MX674Atd 28 ceramic sb ? 25 MX674Aud 28 ceramic sb ? 12 25s maximum conversion time temp range: 0 n c to +70 n c mx574ajn+ 28 plastic dip 1 50 mx574akn+ 28 plastic dip ? 27 mx574aln+ 28 plastic dip ? 10 mx574ajcwi+ 28 wide so 1 50 mx574akcwi+ 28 wide so ? 27 mx574alcwi+ 28 wide so ? 10 mx574ajp+ 28 plcc 1 50 mx574akp+ 28 plcc ? 27 mx574alp+ 28 plcc ? 10 mx574ak/d dice* ? temp range: -40 n c to +85 n c mx574ajepi+ 28 plastic dip 1 75 mx574akepi+ 28 plastic dip ? 38 mx574alepi+ 28 plastic dip ? 19 mx574ajewi+ 28 wide so 1 75 mx574akewi+ 28 wide so ? 38 mx574alewi+ 28 wide so ? 19 temp range: -55 n c to +125 n c mx574asq 28 cerdip* 1 50 mx574atq 28 cerdip* ? 25 mx574auq 28 cerdip* ? 12 mx574asd 28 ceramic sb 1 50 mx574atd 28 ceramic sb ? 25 mx574aud 28 ceramic sb ? 12
???????????????????????????????????????????????????????????????? maxim integrated products 17 max174/mx574a/MX674A industry-standard, complete 12-bit adcs package information for the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages . note that a +, #, or - in the package code indicates rohs status only. package drawings may show a different suffix character, but the drawing pertains to the package regardless of rohs status. chip information process: bicmos package type package code outline no. land pattern no. 28 pdip p28+2 21-0044 28 plcc q28+3 21-0049 90-0235 28 wide so w28+2 21-0042 90-0109
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. the parametric values (min and max limits) shown in the electrical characteristics table are guaranteed. other parametric values quoted in this data sheet are provided for guidance. maxim integrated products, 120 san gabriel drive, sunnyvale, ca 94086 408-737-7600 18 ? 2011 maxim integrated products maxim is a registered trademark of maxim integrated products, inc. max174/mx574a/MX674A industry-standard, complete 12-bit adcs revision history revision number revision date description pages changed 0 3/90 initial release 1 8/11 updated the electrical characteristics and ordering information . added revision history . 2C4

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