A DSP-based Impedance Measurement Device

A preliminary version of the novel digital signal processor (DSP) based electrical impedance measurement device has been developed and evaluated. Used DSP is TMS320F28379D (of Texas Instruments), being a dual core 16/32 bit DSP/DSC (digital signal processor / digital signal controller) with 4 on-chip 16-bit ADC-s, PWM units, lot of flash and SRAM memory etc. For excitation signal the on-chip PWM is used and for acquiring of the response (and excitation) signal waveforms the internal 16-bit ADC-s. By first evaluation the device can work at least in the frequency range from 1 kHz to 100 kHz with resolution and measurement uncertainty (and so also the potential accuracy) of 0,01% or better. Further work include implementation of the simultaneous multifrequency measurement for impedance spectroscopy and evaluation of the applicability of the proposed device for several impedance applications.