The TPS4HC120-Q1 device is a smart high-side switch, with internal charge pump and quad-channel integrated NMOS power FETs. Full diagnostics and high-accuracy current-sense features enable intelligent control of the load. The adjustable current-limit function greatly improves the reliability of the whole system.

The device has logic pins to enable each of the four channels and a separate pin to enable the diagnostic output with two pins to select the channel to be output on the analog current SNS pin. It also implements a global FLT pin to be used as an interrupt to the MCU.

The external high-accuracy current limit allows setting the current-limit value by applications. When overcurrent occurs, the device improves system reliability by clamping the inrush current effectively. The device can also save system cost by reducing the size of PCB traces and connectors, and the capacity of the preceding power stage.

For inductive loads (relays, solenoids, valves), the device implements an active clamp between drain and source to protect itself. During the inductive switching-off cycle, both the energy of the power supply and the load are dissipated on the high-side switch. The device also optimizes the switching-off slew rate when the clamp is active, which helps the system design by keeping the effects of transient power and EMI to a minimum.

When the current consumptions on all channels are small, along with other requirements described in Entry into LPM, the device automatically enters the Low Power Mode. This state has ultra-low quiescent current consumption, and is suitable for the loads that are active when the vehicle is OFF to preserve the battery. There is a dedicated LPM pin that indicates the mode of the device, and can be used as an interrupt signal to wake up the MCU.

The TPS4HC120-Q1 device is able to drive a wide variety of resistive, inductive, and capacitive loads, including low-wattage bulbs, LEDs, relays, solenoids, heaters, and sub-modules.