Fermilab Physics Department TVC chip

The Electronics Group in the Physics Department at Fermilab has designed and has had produced 20 prototypes of a full custom four channel time to voltage converter using the ES2 direct write 2 {mu}m CMOS process. The actual implementation of the design was performed under contract by ASIC designs Inc. of Naperville, Illinois. Each channel has two hit capability and one level of input buffering: that is, up to four voltages representing time internals can be stored from each input for later ADC conversion. The chip produces an edited list of hits and presents the appropriate analog value on its output for each digital value on its hit address lines. The next hit address and analog voltage in the event is presented in response to an external strobe. One current sum proportional to the number of inputs hit for each input buffer is also provided. The chip has been designed to be used on a fastbus TDC card developed here, but it is our belief that it could be adapted to many TDC applications. 2 refs., 8 figs.