Methodology For The Digital Calibration Of Analog Circuits And Systems: With Case Studies (the Springer International Series In Engineering And Computer Science)
by Marc Pastre /
2006 / English / PDF
3.4 MB Download
Methodology for the Digital Calibration of Analog Circuits and
Systems shows how to relax the extreme design constraints in
analog circuits, allowing the realization of high-precision systems
even with low-performance components. A complete methodology
is proposed, and three applications are detailed. To start
with, an in-depth analysis of existing compensation techniques for
analog circuit imperfections is carried out. The M/2+M sub-binary
digital-to-analog converter is thoroughly studied, and the use of
this very low-area circuit in conjunction with a successive
approximations algorithm for digital compensation is described. A
complete methodology based on this compensation circuit and
algorithm is then proposed. The detection and correction of analog
circuit imperfections is studied, and a simulation tool allowing
the transparent simulation of analog circuits with automatic
compensation blocks is introduced. The first application shows how
the sub-binary M/2+M structure can be employed as a conventional
digital-to-analog converter if two calibration and radix conversion
algorithms are implemented. The second application, a SOI 1T DRAM,
is then presented. A digital algorithm chooses a suitable reference
value that compensates several circuit imperfections together, from
the sense amplifier offset to the dispersion of the memory read
currents. The third application is the calibration of the
sensitivity of a current measurement microsystem based on a Hall
magnetic field sensor. Using a variant of the chopper modulation,
the spinning current technique, combined with a second modulation
of a reference signal, the sensitivity of the complete system is
continuously measured without interrupting normal operation. A
thermal drift lower than 50 ppm/°C is achieved, which is 6 to 10
times less than in state-of-the-art implementations. Furthermore,
the calibration technique also compensates drifts due to mechanical
stresses and ageing.
Methodology for the Digital Calibration of Analog Circuits and
Systems shows how to relax the extreme design constraints in
analog circuits, allowing the realization of high-precision systems
even with low-performance components. A complete methodology
is proposed, and three applications are detailed. To start
with, an in-depth analysis of existing compensation techniques for
analog circuit imperfections is carried out. The M/2+M sub-binary
digital-to-analog converter is thoroughly studied, and the use of
this very low-area circuit in conjunction with a successive
approximations algorithm for digital compensation is described. A
complete methodology based on this compensation circuit and
algorithm is then proposed. The detection and correction of analog
circuit imperfections is studied, and a simulation tool allowing
the transparent simulation of analog circuits with automatic
compensation blocks is introduced. The first application shows how
the sub-binary M/2+M structure can be employed as a conventional
digital-to-analog converter if two calibration and radix conversion
algorithms are implemented. The second application, a SOI 1T DRAM,
is then presented. A digital algorithm chooses a suitable reference
value that compensates several circuit imperfections together, from
the sense amplifier offset to the dispersion of the memory read
currents. The third application is the calibration of the
sensitivity of a current measurement microsystem based on a Hall
magnetic field sensor. Using a variant of the chopper modulation,
the spinning current technique, combined with a second modulation
of a reference signal, the sensitivity of the complete system is
continuously measured without interrupting normal operation. A
thermal drift lower than 50 ppm/°C is achieved, which is 6 to 10
times less than in state-of-the-art implementations. Furthermore,
the calibration technique also compensates drifts due to mechanical
stresses and ageing.
