Multichannel ADC IP Core on Xilinx SoC FPGA

Sensing of analogue signals such as voltage, temperature, pressure, current etc. is required to acquire the real time analog signals in the form digital streams. Most of the static analog signals are converted into voltage using sensors, transducers etc. and then measured using ADCs. The digitized samples from ADC are collected either through serial or parallel interface and processed by the programmable chips such as processors, controllers, FPGAs, SOCs etc. In some cases, Multichannel supported ADCs are used to save the layout area when the functionalities are to be realized in a small form factor. In such scenarios, parallel interface for each channel is not a preferred interface considering the more number of interfaces / traces between the components. Hence, Custom, Sink synchronized, Configurable multichannel ADC soft IP core has been developed using VHDL coding to interwork with multichannel supported, time division multiplexed ADCs with serial interface. The developed IP core can be used either as it is with the SPI interface as specified in this paper or with necessary modifications / configurations. The configurations can be the number of channels, sample size, sampling frequency, data transfer clock, type of synchronization – source / sink, control signals and the sequence of the operations performed to configure ADC. The efficiency of implementation is validated using the measurements of throughput, and accuracy for the required range of input with acceptable tolerances. ZYNQ FPGA and LTC2358 ADC are used to evaluate the developed IP core. Integrated Logic Analyser (ILA) which is an integrated verification tool of Vivado is used for Verification.