7.1 Overview

The TPS27S100x is a single-channel, fully-protected, high-side switch with an integrated NMOS and charge pump. Full diagnostics and high-accuracy current-monitor features enable intelligent control of the load. An adjustable current-limit function greatly improves the reliability of the whole system. The device diagnostic reporting has two versions to support both digital fault status and analog current monitor output.

For TPS27S100A, the digital fault status report is implemented with an open-drain structure. For TPS27S100B, high-accuracy current-monitor allows a better real-time monitoring effect and more-accurate diagnostics without further calibration. A current mirror is used to source a fraction ( 1 / K_(IMON)) of the load current. K_(IMON) is a nearly constant value across the temperature and supply voltage.

The external high-accuracy current limit allows setting the current limit value by application. Under start-up or short-circuit conditions, it improves the reliability of the system significantly by clamping the inrush current effectively. It can also save system costs by reducing PCB trace, connector size, and the preceding power-stage capacity. An internal current limit is also implemented in this device. The lower value of the external or internal current-limit value is applied.

An active drain to source voltage clamp is built in to address switching off the energy of inductive loads, such as relays, solenoids, motors, and so forth. During switching-off cycle, both the energy of the power supply and the inductive load are dissipated on the device itself. See Inductive-Load Switching-Off Clamp for more details.

The TPS27S100x device can be used as a high-side switch to drive a wide variety of resistive, inductive, and capacitive loads.