1 ltc8043 serial 12-bit multiplying dac in so-8 improved direct replacement for dac-8043 andmax543 so-8 package dnl and inl over temperature: 0.5lsb easy, fast and flexible serial interface 1lsb maximum gain error 4-quadrant multiplication low power consumption low cost the ltc 8043 is a serial-input 12-bit multiplying digital- to-analog converter (dac). it is a superior pin compatiblereplacement for the dac-8043. improvements include better accuracy, better stability over temperature and supply variations, lower sensitivity to output amplifier offset, tighter timing specifications and lower output ca- pacitance. an easy-to-use 3-wire serial interface is well-suited to remote or isolated applications the ltc8043 is extremely versatile. it can be used for 2-quadrant and 4-quadrant multiplying, programmable gain and single supply applications, such as noninverting voltage output mode. parts are available in 8-pin so and pdip packages and are specified over the extended industrial temperature range, ?0 c to 85 c. features descriptio n u process control and industrial automation remote microprocessor-controlled systems digitally controlled filters and power supplies programmable gain amplifiers automatic test equipment applicatio n s u , ltc and lt are registered trademarks of linear technology corporation. typical applicatio n u so-8 multiplying dac has easy 3-wire serial interface v dd v ref ltc8043 r fb gnd 4 76 5 8 5v v in clock data load clksri ld 1 2 3 i out 33pf v out ltc8043 ?ta01 + lt 1097 integral nonlinearity over temperature digital input code 0 ?.0 integral nonlinerarity (lsb) 0.5 0 1.0 1024 2048 2560 ltc8043 ?tpc02 0.5 512 1536 3072 3584 4095 t a = 25 c t a = 85 c t a = 40 c downloaded from: http:///
2 ltc8043 ltc8043e ltc8043f symbol parameter conditions min typ max min typ max units resolution 12 12 bits inl integral nonlinearity (note 1) 0.5 1 lsb dnl differential nonlinearity guaranteed monotonic, t min to t max 0.5 1 lsb ge gain error (note 2) t a = 25 c 1 2 lsb t min to t max 2 2 lsb gain temperature coefficient (note 3) 15 15p p m / c ( ? gain/ ? temp) i lkg output leakage current (note 4) t a = 25 c 5 5n a t min to t max 25 25 na zero-scale error t a = 25 c 0.03 0.03 lsb t min to t max 0.15 0.15 lsb psrr power supply rejection ratio v dd = 5v 5% 0.0001 0.002 0.0001 0.002 %/% absolute m axi m u m ratings w ww u package/order i n for m atio n w u u v dd to gnd................................................. 0.5v to 7v digital inputs to gnd .................. 0.5v to (v dd + 0.5v) v iout to gnd ............................... 0.5v to (v dd + 0.5v) v ref to gnd.......................................................... 25v v rfb to gnd .......................................................... 25v maximum junction temperature .......................... 150 c operating temperature range ............... 40 c to 85 c storage temperature range ................ 65 c to 150 c lead temperature (soldering, 10 sec).................. 300 c ltc8043en8ltc8043fn8 ltc8043es8 ltc8043fs8 order part number consult factory for military grade parts. accuracy characteristics v dd = 5v, v ref = 10v, v iout = gnd = 0v, t a = t min to t max , unless otherwise specified. electrical characteristics v dd = 5v, v ref = 10v, v iout = gnd = 0v, t a = t min to t max , unless otherwise specified. t jmax = 150 c, ja = 130 c/ w (n8) t jmax = 150 c, ja = 190 c/ w (s8) 1
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top view s8 package
8-lead plastic so n8 package
8-lead pdip 8
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5
v ref
r fb
i out
gnd v dd
clk
sri
ld all grades symbol parameter conditions min typ max units reference input r ref v ref input resistance (note 5) 71 11 5 k ac performance (note 3) output current settling time (notes 6, 7) 0.25 1 s multiplying feedthrough error v ref = 10v, 10khz sinewave 0.7 1 mv p-p digital-to-analog glitch energy (notes 6, 8) 2 20 nvsec thd total harmonic distortion (note 9) 108 92 db output noise voltage density (note 10) 17 nv/ hz analog outputs (note 3) c out output capacitance dac register loaded to all 1s 60 90 pf dac register loaded to all 0s 30 60 pf downloaded from: http:///
3 ltc8043 electrical characteristics v dd = 5v, v ref = 10v, v iout = gnd = 0v, t a = t min to t max , unless otherwise specified. note 7: to 0.01% for a full-scale change, measured from falling edge of ld.note 8: v ref = 0v. dac register contents changed from all 0s to all 1s or from all 1s to all 0s.note 9: v ref = 6v rms at 1khz. dac register loaded with all 1s. note 10: 10hz to 100khz between r fb and i out . calculation from e n = 4ktrb where: k = boltzmann constant (j/k ); r = resistance ( ); t = resistor temperature ( k); b = bandwidth (hz). block diagra m w the denotes specifications 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 out with dac register loaded with all 0s. note 5: typical temperature coefficient is 100ppm/ c. note 6: i out load = 100 in parallel with 13pf. 40k 10k 40k 20k 40k 20k 40k 20k 40k 40k 40k decoder bit 1
(msb) bit 2 bit 3 bit 4 bit 12
(lsb) clk in load v dd v ref r fb i out sri 6 gnd 4 3 2 8043 bd dac register input 12-bit shift register 5 7 8 1 ld clk all grades symbol parameter conditions min typ max units digital inputs v ih digital input high voltage 2.4 v v il digital input low voltage 0.8 v i in digital input current v in = 0v to v dd 0.001 1 a c in digital input capacitance v in = 0v,(note 3) 8p f timing characteristics (note 3) t ds serial input to clock setup time 30 5 ns t dh serial input to clock hold time 60 25 ns t sri serial input data pulse width 80 ns t ch clock pulse width high 80 ns t cl clock pulse width low 80 ns t ld load pulse width 140 ns t asb lsb clocked into input register 0n s to load dac register time power supply v dd supply voltage 4.75 5 5.25 v i dd supply current digital inputs = 0v or v dd 100 a digital inputs = v ih or v in 500 a 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. downloaded from: http:///
4 ltc8043 ti i g diagra u w
w sri ld previous
word bit 1
msb bit 2 bit 11 8043td01 bit 12
lsb t ds t dh t ch t sri t asb t cl t ld clk input typical applicatio n s n u unipolar operation (2-quadrant multiplication) v dd v ref ltc8043 r fb gnd 4 76 5 8 5v v ref
?0v to 10v clksri ld 1 2 3 i out 33pf v out ltc8043 ?ta03 + lt1097 p table 1. unipolar binary code table digital input
binary number
in dac register ? ref (4095/4096)
? ref (2048/4096) = v ref /2
? ref (1/4096)
0v
0.1 f msb lsb
1111 1111 1111
1000 0000 0000
0000 0000 0001
0000 0000 0000 analog output
v out related parts part number description comments ltc1257 complete serial i/o v out 12-bit dac 5v to 15v single supply in 8-pin so and pdip ltc1451/ltc1452/ltc1453 complete serial i/o v out 12-bit dacs 3v/5v single supply in 8-pin so and pdip ltc7541a parallel i/o multiplying 12-bit dac 12-bit wide input ltc7543/ltc8143 serial i/o mulitplying 12-bit dacs clear pin and serial data output (ltc8143) 76 5 5v p 0.1 f v dd v ref ltc8043 r fb gnd 4 8 v ref
?0v to 10v clksri ld 1 2 3 i out v out ltc8043 ?ta04 + 1/2 lt1112 table 2. bipolar offset binary code table +v ref (2047/2048)
+v ref (1/2048)
0v
? ref (1/2048)
? ref (2048/2048) = ? ref r3
20k r1
10k r2
20k + 1/2 lt1112 digital input
binary number
in dac register msb lsb
1111 1111 1111
1000 0000 0001
1000 0000 0000
0111 1111 1111
0000 0000 0000 analog output
v out
33pf bipolar operation (4-quadrant multiplication) linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7487 (408) 432-1900 fax : (408) 434-0507 telex : 499-3977 lt/gp 1195 ? printed in usa ? linear technology corporation 1995 downloaded from: http:///
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