POSFET Touch Sensing Devices: Bias Circuit Design Based on the ACM MOS Transistor Compact Model

摘要

In this article we present a common-drain floating gate bias circuit design for POSFET (Piezoelectric Oxide Semiconductor Field Effect Transistor) touch sensing devices. A graphical-aided methodology, intended to furnish a criterion that assures the selection of the most appropriate bias resistance value, is presented. The methodology utilizes the Advanced Compact MOSFET (ACM) model and the g_m characteristic as function of I_D. A design space map is generated showing the trade-offs between gain, current consumption and components value (i.e. resistance). As a proof of concept of the proposed method, a design example and measurements are presented.