Automotive smart high-side power switch with adjustable overcurrent limitation

Infineon Technologies AG now offers the new automotive smart high-side power switch portfolio PROFET Load Guard 12V. The combination of an adjustable overcurrent limitation and the capacitive load switching mode offers a flexible response to the diverse necessities of modern secondary power distribution and supplies protection mechanisms for safety-critical ADAS integration.

The new dual- and single-channel devices provide a wide current limitation range between 0.3A and 8.7A, depending on the RDS(ON). This feature provides the protection level to be set according to the system needs without microcontroller involvement. It evades peak currents that threaten loads and delivers fast fault isolation to the power distribution side in the possibility of overload conditions due to load failures, e.g. in the sensor fusion box. Loads with high capacitive share, such as ADAS or display modules, can be quickly switched on, utilising the devices’ capacitive load switching (CLS) mode.

The CLS mode enables it to charge several millifarads whilst remaining inside the safe operating area of the smart high-side power switches, raising the overall system robustness. Also, by providing a Safety-Application-Note, the PRO SIL ISO26262-ready devices streamline the use in functional-safety-related applications. Furthermore, the best-in-class low current sense accuracy facilitates accurate module diagnostics and monitoring.

The family’s wide operating voltage range from 3V (cranking: 2.7V) to 28V, with the adjustable overcurrent limitation and the CLS mode, offers maximum load flexibility. If load or system demands change, such as variant handling, the analog overcurrent limit threshold can easily adapt to the new conditions. This is achieved by simply changing the resistor connected to the OCT pin. As well as flexibility, this feature also permits hardware-based wire protection for time-independent loads. The CLS mode also expands the load potential and reacts to increasing capacitive loads, such as modules.

Rated at 2-3A, the family consists of two 90mOhm and two 50mOhm devices, available as single- and dual-channel automotive smart high-side power switches. The proven PG-TS-DSO-14 package offers high compatibility with other SMART7 devices, such as the PROFET +2 12V. Loads with a high capacitive share can be readily addressed through the integrated CLS mode, letting large capacitors rapidly charge within the safe operating area of the PROFET Load Guard 12V. The best-in-class high current sense accuracy tolerance (kILIS) in low current ranges allows highly accurate current sensing.

To support the design-in process of the devices, the family is combined into the PROFET Guard Tool, offered in the Infineon Developer Center. This tool helps evaluating the system protection capability of PROFET Load Guard 12V devices with a given wire and load profile. It also calculates the correct resistor value for the adjustable overcurrent limitation.