Title :
A 20 b dynamic-range floating-point data acquisition system
Author :
Chen, Francis ; Chen, C.S.
Author_Institution :
Dept. of Electr. Eng., Akron Univ., OH, USA
fDate :
2/1/1991 12:00:00 AM
Abstract :
The design and engineering of a floating-point data-acquisition system are described. The system has both automatic gain and software-programmable gain adjustment features. In automatic gain adjustment mode, the gain is set automatically dependent on the input amplitude so that the full conversion resolution is maintained irrespective of the signal dynamic range. A high-speed flash ADC with an approximately 35 ns conversion time is used to convert the signal quickly into 8 b data. A programmable array logic (PAL) then transfers this 8 b digital data into 12 b information for setting the gain of the variable-gain amplifier. The amplifier gain settings are all powers of two; thus, the normalization of the digitized data requires only a bit shifting operation and no complex software division. The gain information and the 12 b sampling ADC output increase the dynamic range to 20 b. The software package includes commands needed for the system initiation, automatic gain or software programmable gain selection, sampling and conversion, and data normalization
Keywords :
analogue-digital conversion; computerised instrumentation; data acquisition; 20 bit dynamic range; 35 ns; amplifier gain settings; automatic gain adjustment; bit shifting operation; data normalization; floating-point data acquisition system; high-speed flash ADC; programmable array logic; software-programmable gain adjustment; system initiation; variable-gain amplifier; Data acquisition; Data engineering; Design engineering; Dynamic range; Maintenance engineering; Operational amplifiers; Power amplifiers; Programmable logic arrays; Sampling methods; Signal resolution;
Journal_Title :
Industrial Electronics, IEEE Transactions on
