1 Introduction

The TPS272C45C is a high-side switch designed for 24-V industrial applications including industrial PLC systems, motor drives, and building automation systems. There is a rising trend for industrial applications, such as safety ultra-low voltage (SELV) systems, to require the high-side switch to withstand up to 60 V. While designing the industrial safety modules, the designers need to account for the failure situations including the fault in the power supply. Because of the use of SELV power supply in such systems, the max voltage during both normal operation and fault events is limited to 60 V. By adding a few components to a system using the TPS272C45C, the device is capable of surviving the 60 V bus voltage in case of a fault event to protect itself and any downstream loads. On the other hand, the higher clamping voltage enabled by the proposed circuit allows for the faster discharge of larger inductive loads while ensuring the safety of the switch. The device also needs to satisfy the industrial safety requirements, including the ability to pass surge standards and inductive load tests. This application note shows the required hardware modifications to the TPS272C45C EVM for 60 V tolerance as well as the test results for the 60 V tolerance, surge, and inductive load driving.