Realization of a passive RTC (Ratio to Time Converter) using a new conversion technique for charge division readout
Farhad Javanmardi, Takeji Sakae, Akihiro Nohtomi, Yusuke Uozumi, M. Matoba · 1997 IEEE Nuclear Science Symposium Conference Record · 2002
A dynamic conversion method is introduced to realize a novel RTC (passive RTC) for the charge division readout position sensing. Almost all the methods used for ratio to time conversion are static methods and start the conversion process after the signal peak sensing. Then, the static RTCs are monopolar input converters. The dynamic conversion performs the conversion process during the position signal forming and is based on the ratio to time responses of delay transmission lines. Then, the dynamic RTCs based on this method are bipolar converters. For the dynamic conversion method the ratio can be converted to time at any adjustable moment on the leading edges of the signals decreases the conversion dead time for on-line readouts. A delay line, using this conversion method, is substituted for a conventional RTC which includes at least 20 active elements. Since the delay line is a passive element, it is possible to install it within the position sensitive chambers. Using the dynamic conversion method, the signals of a Backgammon pattern are converted to position and position resolution of about 2% to the full length were achieved.