UNAP DCM Theory of Operations
POTAS, Matthew Newell · 2012
The UNAP DCM board is capable of measuring currents with a dynamic range of 3 x 10{sup -14} A to 3 x 10{sup -4} A. The design of the DCM closely matches the proven N-1 minigrand family DCM design. The most significant difference is the replacement of the Actel FPGA with an SPI I/O expander. The original DCM design used an Actel FPGA to communicate with the processor over the expansion bus controling the DCM gain and filtering. The UNAP processor communicates with the UDA FPGA over the cPCI bus. The UNAP DCM control functions are accomplished in the UDA FPGA and communicated to the DCM board via an SPI bus.