High and low side high voltage switch with over voltage and over current protection

Abstract

The introduction of monolithic electronics in automotive as well as industrial applications makes switches an ubiquitous building block. In this environment switches need to handle high voltage, high currents densities as well as low power consumption. Cost reduction brought by technology scaling allowed adding safety functions to switches and consequently to improve switches reliability. Current limitation, thermal shutdown, overvoltage and under voltage protections are some of these functionalities. This article review circuit topologies commonly used as switches. A new topology with current limitation and no consumption in stand by operation mode is proposed. Based on this topology, high side and low side switches were integrated in smartMOS™ Freescale proprietary technology. Evaluation results are presented and discussed.