figure 1. ads-919 functional block diagram ref register register 18 bit 1 (msb) 17 bit 2 12 bit 3 11 bit 4 10 bit 5 9 bit 6 8 bit 7 7 bit 8 6 bit 9 5 bit 10 4 bit 11 3 bit 12 2 bit 13 1 bit 14 (lsb) timing and control logic +10v ref. out 21 start convert 16 eoc 15 digital correction logic dac flash adc buffer C + s/h analog input 20 13 +5v supply 22 +12v/+15v supply 19, 23 analog ground 14 digital ground 24 C12v/C15v supply s 2 s 1 block diagram the ads-919 is a high-performance, 14-bit, 2mhz sampling a/d converter. this device accurately samples full-scale input signals up to nyquist frequencies with no missing codes. the ads-919 features outstanding dynamic perfor- mance including a thd of C74db. housed in a small 24-pin ddip or smt (gull- wing) package, the functionally complete ads-919 contains a fast-settling sample-hold ampli? er, a sub- ranging (two-pass) a/d converter, a precise voltage reference, timing/control logic, and error correction circuitry. digital input and output levels are ttl. requiring 15v (or 12v) and +5v supplies, the ads-919 typically dissipates 1.8w (1.5w for 12v). the unit is offered with a unipolar input (0 to +10v). models are available for use in either commercial (0 to +70c) or hi-rel (C55 to +125c) operating temperature ranges. applica- tions include radar, sonar, spectrum analysis, and graphic/medical imaging. product overview features 14-bit resolution 2mhz sampling rate no missing codes functionally complete small 24-pin ddip or smt package low power, 1.8 watts operates from 15v or 12v supplies & +5v supply edge-triggered; no pipeline delays unipolar 0 to +10v input range input/output connections pin function pin function 1 bit 14 (lsb) 24 C12v/C15v supply 2 bit 13 23 analog ground 3 bit 12 22 +12v/+15v supply 4 bit 11 21 +10v reference out 5 bit 10 20 analog input 6 bit 9 19 analog ground 7 bit 8 18 bit 1 (msb) 8 bit 7 17 bit 2 9 bit 6 16 start convert 10 bit 5 15 eoc 11 bit 4 14 digital ground 12 bit 3 13 +5v supply ads-919 14-bit, 2mhz, low-power sampling a/d converters ?? datel ? 11 cabot boulevard, mans? eld, ma 02048-1151 usa ? tel: (508) 339-3000 ? www.datel.com ? e-mail: help@datel.com 01 apr 2011 mda_ads-919.b02 page 1 of 8
physical/environmental parameters min. typ. max. units operating temp. range, case ADS-919MC, gc 0 +70 c ads-919mm, gm C55 +125 c thermal impedance jc 6 c/watt ca 24 c/watt storage temperature range C65 +150 c package type 24-pin, metal-sealed, ceramic ddip or smt weight 0.42 ounces (12 grams) absolute maximum ratings parameters limits units +12v/+15v supply (pin 22) 0 to +16 volts C12v/C15v supply (pin 24) 0 to C16 volts +5v supply (pin 13) 0 to +6 volts digital input (pin 16) C0.3 to +v dd +0.3 volts analog input (pin 20) C4 to +17 volts lead temperature (10 seconds) +300 c +25c 0 to +70c C55 to +125c analog input min. typ. max. min. typ. max. min. typ. max. units input voltage range ? 0 to +10 0 to +10 0 to +10 volts input resistance 1 1 1 k input capacitance 7 15 7 15 7 15 pf digital input logic levels logic "1" +2.0 +2.0 +2.0 volts logic "0" +0.8 +0.8 +0.8 volts logic loading "1" +20 +20 +20 a logic loading "0" C20 C20 C20 a start convert positive pulse width ? 20 200 20 200 20 200 ns static performance resolution 14 14 14 bits integral nonlinearity (f in = 10khz) 0.5 0.75 1 lsb differential nonlinearity (f in = 10khz) 0.5 +0.95 0.5 0.95 0.5 +0.99 lsb full scale absolute accuracy 0.1 0.3 0.2 0.4 0.4 0.8 %fsr unipolar offset error (tech note 2) 0.1 0.25 0.2 0.4 0.4 1.25 %fsr gain error (tech note 2) 0.1 0.3 0.3 .05 0.5 1 % no missing codes (f in = 10khz) 14 14 14 bits dynamic performance peak harmonics (C0.5db) dc to 500khz C76 C72 C76 C70 C74 C69 db 500khz to 1mkhz C76 C70 C76 C70 C74 C69 db total harmonic distortion (C0.5db) dc to 500khz C74 C70 C74 C70 C73 C69 db 500khz to 1mkhz C74 C70 C74 C70 C73 C68 db signal-to-noise ratio (w/o distortion, C0.5db) dc to 500khz 74 77 74 77 71 76 db 500khz to 1mkhz 74 77 74 77 71 75 db signal-to-noise ratio ? (& distortion, C0.5db) dc to 500khz 70 74 70 74 68 73 db 500khz to 1mkhz 70 74 70 74 68 72 db two-tone intermodulation distortion (f in = 200khz, 500khz, f s = 2mhz C0.5db) C80 C80 C79 db noise 300 350 450 vrms input bandwidth (C3db) small signal (C20db input) 9 9 9 mhz large signal (C0.5db input) 8 8 8 mhz feedthrough rejection (f in = 1mhz) 82 82 82 db slew rate 200 200 200 v/s aperture delay time 20 20 20 ns aperture uncertainty 5 5 5 ps rms s/h acquisition time (to 0.003%fsr, 10v step) 150 190 230 150 190 230 150 190 230 ns overvoltage recovery time ? 400 500 400 500 400 500 ns a/d conversion rate 2 2 2 mhz functional specifications (t a = +25c, v cc = 15v (or 12v), +v dd = +5v, 2mhz sampling rate, and a minimum 1 minute warmup ? unless otherwise speci? ed.) ads-919 14-bit, 2mhz, low-power sampling a/d converters ?? datel ? 11 cabot boulevard, mans? eld, ma 02048-1151 usa ? tel: (508) 339-3000 ? www.datel.com ? e-mail: help@datel.com 01 apr 2011 mda_ads-919.b02 page 2 of 8
technical notes +25c 0 to +70c C55 to +125c analog output min. typ. max. min. typ. max. min. typ. max. units internal reference voltage +9.95 +10.0 +10.05 +9.95 +10.0 +10.05 +9.95 +10.0 +10.05 volts drift 5 5 5 ppm/c external current 1.5 1.5 1.5 ma digital outputs logic levels logic "1" +2.4 +2.4 +2.4 volts logic "0" +0.4 +0.4 +0.4 volts logic loading "1" C4 C4 C4 ma logic loading "0" +4 +4 +4 ma delay, falling edge of eoc to output data valid 35 35 35 ns output coding straight binary power requirements , 15v power supply ranges +15v supply +14.5 +15.0 +15.5 +14.5 +15.0 +15.5 +14.5 +15.0 +15.5 volts C15v supply C14.5 C15.0 C15.5 C14.5 C15.0 C15.5 C14.5 C15.0 C15.5 volts +5v supply +4.75 +5.0 +5.25 +4.75 +5.0 +5.25 +4.75 +5.0 +5.25 volts power supply currents +15v supply +45 +60 +45 +60 +45 +60 ma C15v supply C45 C60 C45 C60 C45 C60 ma +5v supply +85 +95 +85 +95 +85 +95 ma power dissipation 1.8 2.2 1.8 2.2 1.8 2.2 watts power supply rejection 0.02 0.02 0.02 %fsr/%v power requirements, 12v power supply ranges +12v supply +11.5 +12.0 +12.5 +11.5 +12.0 +12.5 +11.5 +12.0 +12.5 volts C12v supply C11.5 C12.0 C12.5 C11.5 C12.0 C12.5 C11.5 C12.0 C12.5 volts +5v supply +4.75 +5.0 +5.25 +4.75 +5.0 +5.25 +4.75 +5.0 +5.25 volts power supply currents +12v supply +45 +65 +45 +65 +45 +65 ma C12v supply C45 C60 C45 C60 C45 C60 ma +5v supply +85 +95 +85 +95 +85 +95 ma power dissipation 1.5 1.7 1.5 1.7 1.5 1.7 watts power supply rejection 0.02 0.02 0.02 %fsr/%v footnotes: ? all power supplies must be on before applying a start convert pulse. all supplies and the clock (start convert) must be present during warmup periods. the device must be continuously converting during this time. there is a slight degradation in performance when using 12v supplies. ? see ordering information for availability of 5v input range. contact datel for availability of other input voltage ranges. ? a 2mhz clock with a 200ns wide start convert pulse is used for all production testing. see timing diagram for more details. ? this is the time required before the a/d output data is valid once the analog input is back within the speci? ed range. (snr + distortion) C 1.76 + 20 log full scale amplitude actual input amplitude 6.02 ? effective bits is equal to: 1. obtaining fully speci? ed performance from the ads-919 requires care- ful attention to pc-card layout and power supply decoupling. the device's analog and digital ground systems are connected to each other internally. for optimal performance, tie all ground pins (14, 19 and 23) directly to a large analog ground plane beneath the package. bypass all power supplies and the reference output (pin 21) to ground with 4.7f tantalum capacitors in parallel with 0.1f ceramic capacitors. locate the bypass capacitors as close to the unit as possible. if the user- installed offset and gain adjusting circuit shown in figure 2 is used, also locate it as close to the ads-919 as possible. 2. the ads-919 achieves its speci? ed accuracies without the need for exter- nal calibration. if required, the device's small initial offset and gain errors can be reduced to zero using the input circuit of figure 2. when using this circuit, or any similar offset and gain-calibration hardware, make adjust- ments following warmup. to avoid interaction, always adjust offset before gain. 3. when operating the ads-919 from 12v supplies, do not drive external circuitry with the reference output. the reference's accuracy and drift speci? cations may not be met, and loading the circuit may cause accuracy errors within the converter. 4. applying a start convert pulse while a conversion is in progress (eoc = logic "1") initiates a new and inaccurate conversion cycle. data from the interrupted and subsequent conversions will be invalid. ads-919 14-bit, 2mhz, low-power sampling a/d converters ?? datel ? 11 cabot boulevard, mans? eld, ma 02048-1151 usa ? tel: (508) 339-3000 ? www.datel.com ? e-mail: help@datel.com 01 apr 2011 mda_ads-919.b02 page 3 of 8
to pin 20 of ads-919 15v signal input gain adjust 1.98k 7 50 7 +15v 2k 7 200k 7 20k 7 C15v +15v zero/ o ffset adjust figure 2. ads-919 calibration circuit figure 3. typical ads-919 connection diagram calibration procedure (refer to figures 2 and 3) any offset and/or gain calibration procedures should not be implemented until devices are fully warmed up. to avoid interaction, offset must be adjusted before gain. the ranges of adjustment for the circuit of figure 2 are guaranteed to compensate for the ads-919's initial accuracy errors and may not be able to compensate for additional system errors. all ? xed resistors in figure 2 should be metal-? lm types, and multiturn potentiometers should have tcrs of 100ppm/c or less to minimize drift with temperature. a/d converters are calibrated by positioning their digital outputs exactly on the transition point between two adjacent digital output codes. this can be accomplished by connecting led's to the digital outputs and adjusting until certain led's "? icker" equally between on and off. other approaches employ digital comparators or microcontrollers to detect when the outputs change from one code to the next. for the ads-919, offset adjusting is normally accomplished at the point where the output bits are 0's and the lsb just changes from a 0 to a 1. this digital output transition ideally occurs when the applied analog input is +? lsb (+305v). gain adjusting is accomplished when all bits are 1's and the lsb just changes from a 1 to a 0. this transition ideally occurs when the analog input is at +full scale minus 1? lsb's (+9.999085v). zero/offset adjust procedure 1. apply a train of pulses to the start convert input (pin 16) so the con- verter is continuously converting. if using led's on the outputs, a 200khz conversion rate will reduce ? icker. 2. apply +305v to the analog input (pin 20). 3. adjust the offset potentiometer until the output bits are all 0's and the lsb ? ickers between 0 and 1. gain adjust procedure 1. apply +9.999085v to the analog input (pin 20). 2. adjust the gain potentiometer until the output bits are all 1's and the lsb ? ickers between 1 and 0. table 2. output coding input voltage (0 to +10v) unipolar scale digital output offset msb binary lsb +9.999390 +fs C1lsb 11 1111 1111 1111 +7.500000 +3/4 fs 11 0000 0000 0000 +5.000000 +1/2 fs 10 0000 0000 0000 +2.500000 +1/4 fs 01 0000 0000 0000 +0.000610 +1lsb 00 0000 0000 0001 0.000000 0 00 0000 0000 0000 coding is straight binary; 1lsb = 610v. table 1. zero and gain adjust input volt- age range zero adjust +? lsb gain adjust +fs C1? lsb 0 to +10v +305v +9.999085v ads-919 14-bit, 2mhz, low-power sampling a/d converters ?? datel ? 11 cabot boulevard, mans? eld, ma 02048-1151 usa ? tel: (508) 339-3000 ? www.datel.com ? e-mail: help@datel.com 01 apr 2011 mda_ads-919.b02 page 4 of 8
notes: 1. f s = 2mhz. 2. the ads-919 is an edge-triggered device. all internal operations are triggered by the rising edge of the start convert pulse, which may be as narrow as 20nsec. all production testing is performed at a 2mhz sampling rate with 200nsec wide start pulses. for lower sampling rates, wider start pulses may be used, however, a minimum pulse width low of 20nsec must be maintained. figure 4. ads-919 timing diagram devices do not overheat. the ground and power planes beneath the package, as well as all pcb signal runs to and from the device, should be as heavy as possible to help conduct heat away from the package. electrically-insulating, thermally-conductive "pads" may be installed underneath the package. devices should be soldered to boards rather than "socketed," and of course, minimal air ? ow over the surface can greatly help reduce the package temperature. thermal requirements all datel sampling a/d converters are fully characterized and speci- ? ed over operating temperature (case) ranges of 0 to +70c and C55 to +125c. all room-temperature (ta = +25c) production testing is performed without the use of heat sinks or forced-air cooling. thermal impedance ? gures for each device are listed in their respective speci? ca- tion tables. these devices do not normally require heat sinks, however, standard precautionary design and layout procedures should be used to ensure ads-919 14-bit, 2mhz, low-power sampling a/d converters ?? datel ? 11 cabot boulevard, mans? eld, ma 02048-1151 usa ? tel: (508) 339-3000 ? www.datel.com ? e-mail: help@datel.com 01 apr 2011 mda_ads-919.b02 page 5 of 8
figure 5. ads-919 evaluation board schematic ads-919 14-bit, 2mhz, low-power sampling a/d converters ?? datel ? 11 cabot boulevard, mans? eld, ma 02048-1151 usa ? tel: (508) 339-3000 ? www.datel.com ? e-mail: help@datel.com 01 apr 2011 mda_ads-919.b02 page 6 of 8
figure 6. ads-919 fft analysis figure 7. ads-919 histogram and differential nonlinearity ads-919 14-bit, 2mhz, low-power sampling a/d converters ?? datel ? 11 cabot boulevard, mans? eld, ma 02048-1151 usa ? tel: (508) 339-3000 ? www.datel.com ? e-mail: help@datel.com 01 apr 2011 mda_ads-919.b02 page 7 of 8
mechanical dimensions inches (mm) ordering information model number operating temp. range analog input accessories ADS-919MC 0 to +70c unipolar (0 to +10v) ads-b919/929 evaluation board (without ads-919) ads-919mm C55 to +125c unipolar (0 to +10v) hs-24 heat sinks for all ads-919/929 ddip models ads-919gc 0 to +70c unipolar (0 to +10v) receptacles for pc board mounting can be ordered through amp inc. part #3-331272-8 (component lead socket), 24 required. for mil-std-883 product speci? cations, contact datel. * for information, see ads-929 data sheet. ads-919gm C55 to +125c unipolar (0 to +10v) ads-929mc 0 to +70c bipolar (5v)* ads-929mm C55 to +125c bipolar (5v)* ads-929gc 0 to +70c bipolar (5v)* ads-929gm C55 to +125c bipolar (5v)* ads-929/883 C55 to +125c bipolar (5v)* 0.200 max. (5.080) 0.235 max. (5.969) 0.600 0.010 (15.240) 0.80 max. (20.32) 0.100 typ. (2.540) 0.100 (2.540) 0.018 0.002 (0.457) 0.100 (2.540) 0.040 (1.016) 1.31 max. (33.27) 1 12 13 24 1.100 (27.940) 0.190 max. (4.826) 0.010 (0.254) +0.002 C0.001 seating plane 0.025 (0.635) dimension tolerances (unless otherwise indicated): 2 place decimal (.xx) 0.010 (0.254) 3 place decimal (.xxx) 0.005 (0.127) lead material: kovar alloy lead finish: 50 microinches (minimum) gold plating over 100 microinches (nominal) nickel plating pin 1 index 24-pin ddip versions ADS-919MC ads-919mm ads-929mc ads-929mm ads-929/883 24-pin surface mount versions ads-919gc ads-919gm ads-929gc ads-929gm 0.80 max. (20.32) 0.015 (0.381) max. radius for any pin 1.31 max. (33.02) 0.100 typ. (2.540) 0.100 (2.540) 0.190 max. (4.826) 0.040 (1.016) 0.020 typ. (0.508) 0.020 (0.508) 24 13 12 1 pin 1 index 0.130 typ. (3.302) dimension tolerances (unless otherwise indicated) : 2 place decimal (.xx) 0.010 (0.254) 3 place decimal (.xxx) 0.005 (0.127) lead material: kovar alloy lead finish: 50 microinches (minimum) gold plating over 100 microinches (nominal) nickel plating 0.060 typ. (1.524) 0.010 typ. (0.254) ads-919 14-bit, 2mhz, low-power sampling a/d converters . makes no representation that the use of its products in the circuits described herein, or the use of other technical information contained herein, will not infringe upon existing or future patent rights. the descriptions contained her ein do not imply the granting of licenses to make, use, or sell equipment constructed in accordance therewith. speci? cations are subject to change without notice. www.datel.com ? e-mail: help@datel.com ?? datel 11 cabot boulevard, mans? eld, ma 02048-1151 usa itar and iso 9001/14001 registered 01 apr 2011 mda_ads-919.b02 page 8 of 8
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