1 ltc7545a improved industry standard parallel 12-bit multiplying dac s f ea t u re d u escriptio the ltc ? 7545a is a 12-bit multiplying digital-to-analog converter (dac) with a microprocessor compatible paral- lel input. it is a superior pin compatible replacement for the industry standard ad7545a and ad7545. improvements include better accuracy, better stability over temperature and supply variations and lower sensitivity to output amplifier offset. this very versatile dac is useful for 2-quadrant and 4-quadrant multiplying, programmable gain and filtering and single supply noninverting voltage output operation. parts are available in 20-pin pdip and so packages and commercial and industrial temperature grades. n improved direct replacement for ad7545a and ad7545 n dnl and inl over temperature: 0.5lsb n gain error: 1lsb maximum n 4-quadrant multiplication n single 5v or 15v supply n low power consumption n low cost n process control and industrial automation n software controlled gain adjustment n digitally controlled filter and power supplies n automatic test equipment u s a o pp l ic at i , ltc and lt are registered trademarks of linear technology corporation. u a o pp l ic at i ty p i ca l 2-quadrant multiplying dac has less than 0.5lsb (typ) total unadjusted error v dd v ref ltc7545a r fb dgnd 3 4?5 17 16 2 18 5v v in wr cs 19 20 1 out1 33pf v out 7545a ta01 agnd + 0.1 f lt 1097 digital input code 0 integral nonlinearity (lsb) 4095 7545a ta02 1024 2048 3072 1.0 0.5 0 0.5 1.0 512 1536 2560 3584 t a = 85 c t a = 25 c t a = 40 c integral nonlinearity over temperature
2 ltc7545a wu u package / o rder i for atio a u g w a w u w a r b s o lu t exi t i s v dd to agnd ............................................ C0.5v to 17v v dd to dgnd ............................................. C 0.5v to 17v agnd to dgnd .............................. C 0.5v to v dd + 0.5v dgnd to agnd .............................. C 0.5v to v dd + 0.5v v ref to agnd,dgnd ............................................. 25v r fb to agnd,dgnd ............................................. . 25v digital inputs to dgnd ................. C 0.5v to v dd + 0.5v v out1 to agnd, dgnd ................. C0.5v to v dd + 0.5v maximum junction temperature .......................... 150 c operating temperature range commercial (k, l versions) .................... 0 c to 70 c industrial (b, c versions)................... C 40 c to 85 c storage temperature range ................ C65 c to 150 c lead temperature (soldering, 10 sec)................. 300 c ltc7545abg ltc7545abn ltc7545absw ltc7545acg ltc7545acn ltc7545acsw ltc7545akg ltc7545akn ltc7545aksw ltc7545alg ltc7545aln ltc7545alsw order part number t jmax = xxx c, q ja = xxx c/w (g) t jmax = 150 c, q ja = 100 c/w (n) t jmax = 150 c, q ja = 130 c/w (sw) consult factory for military grade parts. v dd = 5v or 15v, v ref = 10v, v out1 = agnd = 0v, t a = t min to t max, unless otherwise noted. electrical characteristics ltc7545ak/ab ltc7545al/ac symbol parameter conditions min typ max min typ max units accuracy resolution l 12 12 bits inl integral nonlinearity (note 1) t a = 25 c 0.5 0.5 lsb (relative accuracy) t min to t max l 0.5 0.5 lsb dnl differential nonlinearity guaranteed monotonic t a = 25 c 1 0.5 lsb t min to t max t min to t max l 1 0.5 lsb ge gain error (note 2) t a = 25 c 2 1lsb t min to t max l 3 2lsb gain temperature coefficient (note 3) d gain/ d temperature l 1 5 1 5 ppm/ c i lkg out1 leakage current (note 4) t a = 25 c 10 10 na t min to t max l 50 50 na psrr power supply rejection l 0.002 0.002 %/% reference input r ref v ref input resistance (note 5) l 8 11 15 8 11 15 k w ac performance output current settling time (notes 3, 6, 7) l 11 m s propagation delay (notes 3, 6, 8) l 150 150 ns digital-to-analog glitch impulse (notes 6, 9) l 5 5 nv-sec multiplying feedthrough error v ref = 10v, 10khz sine wave l 55mv p-p analog outputs c out output capacitance (note 3) db0 to db11 = 0v, c out1 l 30 70 30 70 pf wr, cs = 0v db0 to db11 = v dd, c out1 l 60 150 60 150 pf wr, cs = 0v out1 agnd dgnd db11 (msb) db10 db9 db8 db7 db6 db5 r fb v ref v dd wr cs db0 (lsb) db1 db2 db3 db4 1 2 3 4 5 6 7 8 9 10 top view 20 19 18 17 16 15 14 13 12 11 n package 20-lead pdip sw package 20-lead plastic so wide g package 20-lead plastic ssop
3 ltc7545a electrical characteristics v dd = 5v, v ref = 10v, v out1 = agnd = 0v, t a = t min to t max, unless otherwise noted. all grades symbol parameter conditions min typ max units digital inputs v ih digital input high voltage l 2.4 v v il digital input low voltage l 0.8 v i in digital input current l 0.001 1 m a c in digital input capacitance (note 3) v in = 0v l 8pf timing characteristics (note 3) t cs cs to wr setup time l 100 ns t ch cs to wr hold time l 0ns t wr write pulse width l 100 ns t ds data setup time l 100 ns t dh data hold time l 5ns power supply v dd supply voltage l 4.75 5 5.25 v i dd supply current all digital inputs = v ih or v il l 2ma all digital inputs = 0v or v dd l 10 100 m a v dd = 15v, v ref = 10v, v out1 = agnd = 0v, t a = t min to t max, unless otherwise noted. the l denotes specificatons which apply over the full operating temperature range. note 1: 0.5lsb = 0.012% of full scale. note 2: using internal feedback resistor. note 3: guaranteed by design, not subject to test. note 4: i out1 with dac register loaded to all 0s. note 5: typical temperature coefficient is 100ppm/ c. note 6: out1 load = 100 w in parallel with 13pf. note 7: to 0.01% for a full-scale change, measured from the falling edge of wr, cs = 0v. note 8: from digital input change to 90% of final analog output. note 9: v ref = 0v. dac register contents changed from all 0s to all 1s or all 1s to all 0s. all grades symbol parameter conditions min typ max units digital inputs v ih digital input high voltage l 13.5 v v il digital input low voltage l 1.5 v i in digital input current l 1 m a c in digital input capacitance (note 3) v in = 0v l 8pf timing characteristics (note 3) t cs cs to wr setup time l 75 ns t ch cs to wr hold time l 0ns t wr write pulse width l 75 ns t ds data setup time l 60 ns t dh data hold time l 5ns power supply v dd supply voltage l 14.25 15 15.75 v i dd supply current all digital inputs = v ih or v il l 2ma all digital inputs = 0v or v dd l 10 100 m a
4 ltc7545a 40k 10k 40k 20k 40k 20k 40k 20k 40k 40k 40k decoder load v dd v ref r fb out1 agnd dgnd 3 2 1 20 7545a bd input data latches 16 45 67 15 db11 (msb) db10 db9 db8 ??? db0 (lsb) 17 18 19 wr cs block diagra m w ti i g diagra u ww t ch t cs t ds t dh t wr data valid data in db0 to db11 wr cs 7545a td
5 ltc7545a typical applicatio n s n u unipolar operation (2-quadrant multiplication) analog output v out msb lsb 1111 1111 1111 C v ref (4095/4096) 1000 0000 0000 C v ref (2048/4096) = C v ref /2 0000 0000 0001 C v ref (1/4096) 0000 0000 0000 0v digital input binary number in dac latch table 1. unipolar binary code table v dd v ref ltc7545a r fb out1 dgnd agnd 3 2 17 16 4?5 18 5v or 15v v ref ?0v to 10v p wr cs db11 to db0 19 20 1 33pf 0.1 f v out 0v to ?v ref 7545a ta03 + lt1097
6 ltc7545a typical applicatio n s n u bipolar operation (4-quadrant multiplication) v dd v ref ltc7545a r fb out1 dgnd agnd 3 2 17 16 4?5 18 5v or 15v v ref ?0v to 10v p wr cs db11?b0 19 20 1 33pf r1 10k 0.1 f v out 7545a ta04 + 1/2lt1112 + 1/2lt1112 r2 20k r3 20k analog output v out table 2. bipolar offset binary code table msb lsb 1111 1111 1111 v ref (2047/2048) 1000 0000 0001 v ref (1/2048) 1000 0000 0000 0v 0111 1111 1111 Cv ref (1/2048) 0000 0000 0000 Cv ref (2048/2048) = Cv ref digital input binary number in dac latch
7 ltc7545a package descriptio n u dimensions in inches (millimeters) unless otherwise noted. information furnished by linear technology corporation is believed to be accurate and reliable. however, no responsibility is assumed for its use. linear technology corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. n package 20-lead pdip (narrow 0.300) (ltc dwg # 05-08-1510) g package 20-lead plastic ssop (0.209) (ltc dwg # 05-08-1640) g20 ssop 1098 0.13 ?0.22 (0.005 ?0.009) 0 ?8 0.55 ?0.95 (0.022 ?0.037) 5.20 ?5.38** (0.205 ?0.212) 7.65 ?7.90 (0.301 ?0.311) 1234 5 6 7 8910 7.07 ?7.33* (0.278 ?0.289) 17 18 14 13 12 11 15 16 19 20 1.73 ?1.99 (0.068 ?0.078) 0.05 ?0.21 (0.002 ?0.008) 0.65 (0.0256) bsc 0.25 ?0.38 (0.010 ?0.015) note: dimensions are in millimeters dimensions do not include mold flash. mold flash shall not exceed 0.152mm (0.006") per side dimensions do not include interlead flash. interlead flash shall not exceed 0.254mm (0.010") per side * ** n20 1098 0.020 (0.508) min 0.125 (3.175) min 0.130 0.005 (3.302 0.127) 0.065 (1.651) typ 0.045 ?0.065 (1.143 ?1.651) 0.018 0.003 (0.457 0.076) 0.005 (0.127) min 0.100 (2.54) bsc 0.255 0.015* (6.477 0.381) 1.040* (26.416) max 12 3 4 5 6 7 8 910 19 11 12 13 14 16 15 17 18 20 0.009 ?0.015 (0.229 ?0.381) 0.300 ?0.325 (7.620 ?8.255) 0.325 +0.035 0.015 +0.889 0.381 8.255 () *these dimensions do not include mold flash or protrusions. mold flash or protrusions shall not exceed 0.010 inch (0.254mm)
8 ltc7545a sn7545a 7545afs lt/gp 0596 10k ? printed in usa ? linear technology corporation 1996 linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7417 (408) 432-1900 l fax : (408) 434-0507 l telex : 499-3977 package descriptio n u dimensions in inches (millimeters) unless otherwise noted. related parts part number descripton comments ltc1257 complete serial i/o v out 12-bit dac 5v to 15v single supply in 8-pin so and pdip ltc1450/ltc1450l complete parallel input v out 12-bit dacs rail-to-rail v out , 3v/5v single supply, 12-bit or (8 + 4) bit loading ltc1451/ltc1452/ltc1453 complete serial i/o v out 12-bit dacs rail-to-rail v out , 3v/5v single supply in 8-pin so and pdip ltc7541a parallel i/o multiplying i out 12-bit dac 12-bit wide parallel input ltc7543/ltc8143 serial i/o multiplying i out 12-bit dacs clear pin and serial data output (ltc8143) ltc8043 serial i/o multiplying i out 12-bit dac 8-pin so and pdip sw package 20-lead plastic small outline (wide 0.300) (ltc dwg # 05-08-1620) s20 (wide) 1098 note 1 0.496 ?0.512* (12.598 ?13.005) 20 19 18 17 16 15 14 13 1 23 4 5 6 78 0.394 ?0.419 (10.007 ?10.643) 910 11 12 0.037 ?0.045 (0.940 ?1.143) 0.004 ?0.012 (0.102 ?0.305) 0.093 ?0.104 (2.362 ?2.642) 0.050 (1.270) bsc 0.014 ?0.019 (0.356 ?0.482) typ 0 ?8 typ note 1 0.009 ?0.013 (0.229 ?0.330) 0.016 ?0.050 (0.406 ?1.270) 0.291 ?0.299** (7.391 ?7.595) 45 0.010 ?0.029 (0.254 ?0.737) note: 1. pin 1 ident, notch on top and cavities on the bottom of packages are the manufacturing options. the part may be supplied with or without any of the options dimension does not include mold flash. mold flash shall not exceed 0.006" (0.152mm) per side dimension does not include interlead flash. interlead flash shall not exceed 0.010" (0.254mm) per side * **
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