A multi-channel phase detector using programmable logic devices

Recent developments in programmable logic devices have led to in-system programming capabilities for FPGA (field programmable logic array) and CPLD (complex programmable logic device) devices using inexpensive programming heads and PC-type computers. This development has major advantages for electronic equipment used in a research setting. Many of the devices are electrically erasable and re-programmable hundreds or thousands of times, allowing fast in-system circuit changes or error-correction in the field. This paper describes the successful application of a programmable logic device to a multi-channel phase detector for the HHFW RF systems on NSTX.