Innovative frequency measurement technique used in the design of a single channel frequency to digital converter ASIC

The frequency to digital converter (FDC) is an application specific integrated circuit (ASIC). The chip has been designed to handle one input channel but can easily be expanded to handle multiple channels of frequencies. The channel is capable of measuring frequencies from 100 Hz to 100 kHz. The power consumption of the chip is very low. The frequency measurement accuracy is better than 0.1%. The conversion rate per channel is 100 samples which can be varied too. The chip has built in test equipment (BITE) to verify its operation. It is able to generate frequencies like 8, 4, 2 and 1 MHz which can be fed as optional clock frequencies depending on the accuracy desired. The FDC chip can be interfaced to a 16 bit bus. To meet these stringent specifications of the FDC chip an innovative frequency measurement technique has been devised called the hybrid technique of frequency measurement. The technique proves to be very accurate and it is found that by varying the sampling rate the range of input frequencies over which this accuracy can be achieved also changes.