September, 1996 
 

 

Confused about which D-A converter to use for what application?

 
The following table, put together with inputs from major digital-to-analog-converter manufacturers, should help. 

Application engineers at these companies are continuously bemused by engineers who want to use (say) a 16- or 18-bit audio converter for machine-tool applications.
Novice users don't realize that the 16 bits promoted with regard to audio D-A converters is an ac specification describing the dynamic range of the device, and not its dc accuracy. (It will never repeatedly resolve one part in 65,535 - nor does it have to for consumer audio.) 
The mechanical play in a robotic arm or machine tool, moreover, typically makes it impossible to maintain 16-bit accuracy. A dc-accurate 12-bit converter is preferred for these applications.

The table here maps out the key specifications and sources of components for different applications.
 
Process control
(transmitters)		 12 bits, DNL=1 LSB, INL=±1/2 LSB, 4-20-mA current-loop output, -40¡C to +85¡C temperature range  $4-7 Maxim  MAX535, MAX538; 
Analog Devices  AD421;
Linear Technology LTC1451, LTC1446 (dual); 
Micro Linear  ML 2375 
Process control
(high accuracy) 		 14-16-bit resolution, 
10-ms settling time, 
DNL=1 LSB, monotonicity		 $8-16 Maxim  MAX542, MAX545; 
Burr-Brown  DAC712, DAC714, DAC715;
Crystal Semiconductor
ATE pin electronics,
arbitrary waveform generators 		 12-14-bit resolution, 
100-125-MHz conversion rate, 
DNL=1 LSB, multiple channels
(or multiple DACs in one package) 		 $8.75-30  Maxim  MAX547;
Analog Devices AD8600; 
Harris  HI5741;
Linear Technology LTC1446 (dual), LTC1458 (quad);
Signal Processing Technology  SPT9712 
Cell phones, VCO control 8 bits, DNL=1 LSB,
2.7-3.6-V supply voltage,
< 1-mA current		 $2.25-4.75 Maxim  MAX512, MAX522;
Linear Technology LTC1451;
Micro Linear  ML2330 
Portable instruments 2.7-V supply, small size, 
current £ 1 mA 		 $2.80-4.75
(for singles) 		 Maxim  MAX 533;
Linear Technology LTC1451, LTC1446 (dual); 
Micro Linear ML 2330 
Digital audio 16-20-bit resolution, THD and noise = -88 to -92 dB, dynamic range = 96 dB to -98 dB  $3.15-8 Burr-Brown  PCM1710, PCM1717/1718;
Analog Devices AD1857;
Crystal Semiconductor CS4327, CS4329, CS 4330 
RF frequency synthesizers Direct Digital Synthesis 10-12 bits, 100-125-MHz conversion rate, INL = 1.5 LSB, DNL = 1.0 LSB  $8.75-$30 Analog Devices AD9850;
Harris  HI5721, HI5731;
Signal Processing Technology  SPT9712 
Radar processing Direct Digital Synthesis 6-12 bits, 100-1,000-MHz conversion rate, INL = 1.5 LSB, DNL = 1.0 LSB $125-$295 Signal Processing Technology  SPT7610;
Datel DAC-HF12 
Video (professional) 10-12-bit resolution, 80-MHz conversion rate, INL = 1.25 LSB, DNL = 0,25 LSB  $7-19.95 for 10 bits, 
$145 for 12 bits		 Harris  HI5780, 
Signal Processing Technology  SPT7861; SPT7930 (12-bit); 
Datel  DAC-330, DAC-338 
Video (consumer) 8 bits, 40-MHz conversion rate, INL = 1.3 LSB, DNL = 0,25 LSB  $3.20-3.85 
(for singles) 		 Harris  HI1171, HI1177 (dual); 
Signal Processing Technology  SPT5100 (dual and triple) 
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