With reliability and monitoring of vehicle electric systems becoming increasingly important, especially for autonomous driving, Eberspächer said it is rising to these challenges with its powerful and compact PowerSentinel Advanced Switching Solution (PASS). The new semiconductor switch carries and safeguards high currents in various environments in low-voltage networks up to safety integrity level ASIL D.
Whether it’s in redundant vehicle electric systems for autonomous driving, for critical safety loads such as electric brakes and controls (“X‑by‑wire”) or as an electronic semiconductor-based fuse (e-fuse) — the PowerSentinel protects subnetworks and isolates them from the vehicle electric system in case of an emergency, Eberspächer said. This feature is essential, for example, in the case of short circuits, cable breaks and overvoltage events. The semiconductor switch can carry currents of up to 2000 amps for a short time and 200 amps continuously. The low quiescent current of less than 100 µA with an active disconnector prevents discharge of the battery. The semiconductor switch was initially designed for 12 volts, but the option of a 24-volt or 48-volt variant will be available in the future.
Optimized geometry and needs-based configuration
The growing number of electrical functions is increasing the demand for control units in modern vehicles — and therefore space is becoming ever tighter. Moreover, every gram of weight saved plays its part in extending the range of electric engines. With dimensions of 14.76 by 10.8 by 2.19 centimeters, the PowerSentinel makes installation in the vehicle very easy. In addition, the modular concept behind the configuration of the switch offers the customer flexibility in terms of both hardware and software. For example, there is a choice between various safety levels up to ASIL D in accordance with ISO 26262 and a variety of diagnostic requirements can be met. The PowerSentinel comes with a LIN bus connection to the vehicle electric system as standard. CAN is also available as an alternative. The PowerSentinel was designed in-house by Eberspächer and its specifications have been drawn up on the basis of intensive discussions with customers and market analyses. It will be available from the end of 2024.
Patents for lower power loss and smaller space requirements
In the PowerSentinel, Eberspächer brings together its expertise and experience from more than 20 years of development in automotive electronics. The patented current measurement with no shunt resistor reduces power loss and waste heat. This means there is no need for a heat sink even at continuously high currents, which in turn reduces the installation space required. The optimized busbar concept is also a patented approach that makes transport of the current through the printed circuit board as efficient as possible and generates less waste heat. Extensive knowledge of semiconductor-based switches in modern vehicle electric systems is also evident in the equally innovative diagnostic capabilities, the company said. It is possible to test the switch continuously in closed and conducting state without opening it — even while driving. The PowerSentinel is a flexible component that can be used in various circuit configurations to protect the low-voltage electric system of modern vehicles.
