This work presents main approaches to developing a programmable mixed-signal front-end for sensor electronics based on signal transimpedance amplification and integration. In accordance to Internet of Things concept requirements a Programmable System on Chip PSoC 5LP is used for mixed-signal front-end implementation. In comparison to the basic transimpedance amplification and integration circuits, the output voltage of new solution is modulated over the whole voltage range of the power supply. As a result, the enhanced resolution and accuracy of further analog-to-digital conversion are obtained. Simulation and experimental results of parameters investigations have been presented.