ADSD-1402S dual, 14-bit, 2msps sampling a/d converter features v 14-bit resolution; 2msps sampling rate v functionally complete; 5v input range v no missing codes over full temperature range v edge-triggered; no pipeline delays v 5v supplies, 0.6 watts v small, 40-pin, low-cost surface-mount tdip v 79db snr, C80db thd v ideal for both time and frequency domain applications v out-of-range indicator general description datel's ADSD-1402S is a functionally complete, dual 14- bit, 2msps, sampling a/d converter. its standard, 40-pin, triple-wide smt dip contains two fast-settling sample/hold ampli?ers, two 14-bit a/d converters, multiplexed output buffers, a precision reference, and all the timing and control logic necessary to operate from either two or a single start convert pulse. the ADSD-1402S is optimized for wideband frequency- domain applications and is fully fft tested. the adsd- 1402s requires only 5v supplies and typically consumes 0.6 watts. models are available in either commercial 0 to +70c or military -55 to +125c (-ex suf?x model) operating temperature ranges. input/output connections 1 input a 40 input b 2 +5va 39 +5va 3 analog ground 38 analog ground 4 gain a 37 gain b 5 offset a 36 offset b 6 range 35 n/c 7 2.5v ref 34 n/c 8 analog ground 33 analog ground 9 C5v 32 C5v 10 enable a 31 enable b 11 start a 30 start b 12 +5vd 29 eoc 13 bit 14 (lsb) 28 bit 1 (msb) 14 bit 13 27 bit 2 15 bit 12 26 bit 3 16 bit 11 25 bit 4 17 bit 10 24 bit 5 18 bit 9 23 bit 6 19 bit 8 22 bit 7 20 dgnd 21 dgnd pin function pin function figure 1. ADSD-1402S functional block diagram datel, inc., 11 cabot boulevard, mans?eld, ma 02048-1151 (u.s.a.) v tel: (508) 339-3000 fax: (508) 339-6356 v for immediate assistance: (800) 233-2765
ADSD-1402S 2 functional specifications (t a = +25c, +v dd = +5v, vee = C5v, 2msps sampling rate,vin = 5v and a minimum 7 minute warmup unless otherwise speci?ed.) analog inputs min. typ. max. units input voltage range 5v volts input impedence 400 7 input capacitance 7 15 pf digital inputs logic levels logic "1" +2.0 volts logic "0" +0.8 volts logic loading "1" +20 a logic loading "0" C20 a performance integral non-linearity +25c(?n=10khz) 1 lsb 0 to +70c 1 lsb C55 to +125c 2 lsb differential non-linearity (f in = 10khz) +25c C0.99 0.5 +1.75 lsb 0 to +70c C0.99 0.5 +2.5 lsb C55 to +125c C0.99 0.75 +2.5 lsb bipolar offset error +25c (see figure 3) 0.25 0.5 %fsr 0 to +70c 0.25 0.5 %fsr C55 to +125c 0.5 0.8 %fsr gain error +25c (see figure 3) 0.3 0.6 %fsr 0 to +70c 0.3 0.6 %fsr C55 to +125c 0.6 0.8 %fsr no missing codes (f in = 975khz) 14 bits C55 to +125c resolution 14 bits outputs output coding offset bin. logic level logic "1" +2.4 volts logic "0" +0.4 volts logic loading "1" C160 a logic loading "0" +6.4 ma internal reference voltage, +25c +2.45 +2.5 +2.55 volts 0 to +70c +2.45 +2.5 +2.55 volts external current 5 ma absolute maximum ratings parameters limits units +5v supply (pins 2, 12, 39) 0 to +6 volts C5v supply (pins 9, 32) 0 to C6 volts digital inputs (pins 3, 10, 11, 31) C0.3 to +v dd +0.3 volts analog input (pins 1, 40) 5 volts lead temp. (10 seconds) +300 c footnote: ? same speci?cation as in-band harmonics and peak harmonics. dynamic performance min. typ. max. units total harm. distort. (C0.5db) dc to 500khz C75 C72 db 500khz to 1mhz C73 C70 db signal-to-noise ratio (w/o distortion, C0.5db dc to 500khz 75 79 db 500khz to 1mhz 76 80 db signal-to-noise ratio (and distortion, C0.5db) dc to 500khz 70 74 db 500khz to 1mhz 69 73 db spurious free dyn. range ? dc to 500khz C85 C74 db 500khz to 1mhz C74 C70 db two-tone imd distortion (f in = 975khz, fs = 2.0mhz, C0.5db) C76 db input bandwidth (C3db) small signal (C20db input) 16 mhz large signal (C0.5db input) 12 mhz slew rate 250 v/s aperture delay time 10 ns aperature uncertainty 5 ps s/h acq. time , (to 0.003%fsr) step input 100 150 ns conversion rate 2 mhz feedthrough rejection (f in = 1mhz) 85 db noise 250 vrms power requirements power supply ranges C5v supply C5.25 C5 C4.75 volts +5v supply +4.75 +5.0 +5.25 volts power supply currents C5v supply C80 C70 ma +5v supply +50 +70 ma power dissipation 0.6 0.75 watts power supply rejection 0.01 %fsr%v physical/environmental oper. temp. range, ambient ADSD-1402S 0 +70 c ADSD-1402S-ex C55 +125 c storage temperature range C65 +150 c weight 16.1/0.6 grams/oz package type 40-pin, smt tdip
ADSD-1402S 3 3. full-scale (gain) adjustments set the output of the voltage reference used in step 2 to the value shown in table 2. table 2. offset and gain adjustments input offset adjust gain adjust range +1/2 lsb fs C 1? lsb 5v +0.000305v +4.999085v adjust the gain trimpot r1 until the output code ?ickers equally between 11 1111 1111 1110 and 11 1111 1111 1111 4. repeat above steps for analog input b (pin 40). use trim- pot r3 for the zero (offset) adjustment and trimpot r4 for the full-scale (gain) adjustment. 5. to con?rm proper operation of the device, vary the preci- sion reference voltage source to obtain the output coding technical notes 1. rated performance requires using good high-frequency circuit board layout techniques. connect the digital and analog grounds to one point, the analog ground plane be- neath the converter. due to the inductance and resistance of the power supply return paths, return the analog and digital ground separately to the power supplies. figure 2. ADSD-1402S timing diagram calibration procedure 1. connect the converter per figure 3. apply a pulse of 100 nanoseconds minimum to start convert (pin 11) at a rate of 200khz. this rate is chosen to reduce ?icker if led's are used on the outputs for calibration purposes. 2. zero (offset) adjustments apply a precision voltage reference source between ana- log input a (pin 1) and signal ground (pin 3), then adjust the reference source output per table 2. adjust trim- pot r2 until the code ?ickers equally between 10 0000 0000 0000 and 10 0000 0000 0001. table 3. output coding 11 1111 1111 1111 +4.999390 +fs C 1lsb 11 1000 0000 0000 +4.250000 +3/4fs 11 0000 0000 0000 +2.500000 +1/2fs 10 0000 0000 0000 0.000000 0 01 0000 0000 0000 C2.500000 C1/2fs 00 1000 0000 0000 C4.250000 C3/4fs 00 0000 0000 0001 C4.999390 Cfs+1lsb 00 0000 0000 0000 C5.000000 Cfs output coding input range bipolar msb lsb 5v scale
ADSD-1402S 4 thermal requirements the ADSD-1402S sampling a/d converter is fully characterized and speci?ed over the commercial operating temperature (ambient) range of 0 to +70c and military temperature range of C55 to +125c (ex suf?x). all room-temperature (t a = +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?cation tables. these devices do not normally require heat sinks, however, standard precautionary design and layout procedures should be used to ensure 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. 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. figure 3. ADSD-1402S connection diagram notes: ? recommended to use same supply source for +5 analog and +5 digital. try using as clean of a supply as possible (bypass caps., 10uf and .1uf). ? outputs are enabled by either turning enable a (pin 10) or enable b (pin 31) low for prespective analog inputs a or b. a high on enable a or enable b results in disabling the output bus (high z).
ADSD-1402S datel 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 herein 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. the datel logo is a registered datel, inc. trademark. model number operating temp. range ADSD-1402S 0 to +70c ADSD-1402S-ex C55 to +125c ordering information mechanical dimensions inches (mm) a hybrid through-hole adsd-1402 version is available for high-reliability applications 1.109 (28.17) 0.015 thick copper leads bottom of leads are coplanar to 0.005 2.10 (53.34) 0.025 (0.635) typ 0.100 (2.54) typ 1.900 (48.26) 0.10 (2.54) 0.262 (6.65) 0.06 (15.24) 1.109 (28.17)
|
