HARDWARE-SOFTWARE EMBEDDED SYSTEM OF SIGNAL FREQUENCY SELECTION ON GYRATOR

Abstract

The work is devoted to the problem of frequency-selective signal conversion in microelectronic sensor devices. It has been shown that the signal path of such devices, in particular, sensor nodes in the concept of the Internet of Things, must meet the requirements of embedded systems using a mixed analog-digital front end. The analysis of the signal transformation of photovoltaic sensors, in particular the problem of a significant parasitic influence of extraneous non-informative optical radiation and electromagnetic interference, has been carried out. SPICE models of photovoltaic sensor signal circuits providing frequency selection on bandwidth filters have been synthesized. The main approaches of hardware-software implementation of the built-in system of frequency selection with the mixed-signal transformation are considered. The signal path of the embedded system includes a gyrator, a software-controlled amplifier, a synchronous demodulator, an analog-to-digital converter, and a digital filter. The implementation is carried out on the platform of the programmable system on a PSoC chip. The integrated circuits of the PSoC 5 LP Family Cypress Semiconductor Corporation are used with a wide range of programmable analog front-end nodes, in particular operating amplifiers, comparators, units on switching capacitors, reference voltage sources on the principle of the forbidden zone, analog multiplexers, signal synthesizers, etc. The efficiency of the mixed analog and digital signal conversion is shown.