THE NEXT GENERATION AIRBORNE DATA ACQUISITION SYSTEMS PART II – SPECIFICATION, TRADE-OFFS AND SOME LESSONS LEARNED

• Main Author: Sweeney, Paul
• Other Authors: ACRA CONTROL
• Language: en_US
• Published: International Foundation for Telemetering 2003
• Subjects: FTI; ADC; ENOB; THD; SNR; DNL
• Online Access: http://hdl.handle.net/10150/605360; http://arizona.openrepository.com/arizona/handle/10150/605360

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada === The advent of a new generation of analog to digital converters (ADC’s) provides the aerospace signal-conditioning engineer with many design advantages, trade-offs and challenges for their next generation of signal conditioning systems. These advantages include increased range, resolution, accuracy, channel-count and sampling rate. However, in order to capitalize on these advantages, it is important to understand the trade-offs involved and to specify these systems correctly. Trade-offs include: • Analog vs. Digital signal conditioning • Implementation issues such as 12-bits vs. 16-bits (or even 24-bits) • Topology issues such as multiplexers vs. multiple ADC’s • Filter-type selection • Sigma-Delta vs. Successive Approximation ADC’s. Specification challenges include: • Total DC error vs. gain and offset (and drift, excitation, DNL, crosstalk, etc.) • ENOB vs. SINAD (or THD, SNR or Noise) • Coherency issues such as filter phase distortion vs. delay This paper will discuss some of these aspects and attempts to produce a succinct specification for the next generation of airborne signal conditioning, while also outlining some of the lessons learned in developing the same.