The Use of low resistivity substrates for optimal noise reduction, ground referencing, and current conduction in mixed signal ASICs

Technical Report · Mon Dec 01 04:00:00 EST 1997

DOI:https://doi.org/10.2172/577002· OSTI ID:577002

Zimmerman, Tom ^[1]

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1. Fermilab

This paper is distilled from a talk given at the 3rd International Meeting on Front End Electronics in Taos, N.M. on Nov. 7,1997. It is based on experience gained by designing and testing the SVX3 128 channel silicon strip detector readout chip. The SVX3 chip organization is shown in Fig. 1. The Front End section consists of an integrator and analog pipeline designed at Fermilab, and the Back End section is an ADC plus sparsification and readout logic designed at LBL. SVX3 is a deadtimeless readout chip, which means that the front end is acquiring low level analog signals while the back end is digitizing and reading out digital signals. It is thus a true mixed signal chip, and demands close attention to avoid disastrous coupling from the digital to the analog sections. SVX3 is designed in a bulk CMOS process (i.e., the circuits sit in a silicon substrate). In such a process, the substrate becomes a potential coupling path. This paper discusses the effect of the substrate resistivity on coupling, and also goes into a more general discussion of grounding and referencing in mixed signal designs and how low resistivity substrates can be used to advantage. Finally, an alternative power supply current conduction method for ASICs is presented as an additional advantage which can be obtained with low resistivity substrates. 1 ref., 13 figs., 1 tab.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 577002
• Report Number(s): FERMILAB-TM-2035; oai:inspirehep.net:452005
• Country of Publication: United States
• Language: English

Related Subjects

ANALOG SYSTEMS
ANALOG-TO-DIGITAL CONVERTERS
COUPLING
DIGITAL SYSTEMS
ELECTRIC CONDUCTIVITY
ELECTRIC GROUNDS
EXPERIMENTAL DATA
NOISE
POWER SUPPLIES
SI SEMICONDUCTOR DETECTORS
SUBSTRATES