Ideal-diode controller, uninterrupted power supply in autonomous driving and ADAS
Hot Swap Controller, External N-Channel MOSFET… Load Protection During Hot Swap Events

STMicroelectronics (ST) has launched an integrated hot-swap, ideal-diode controller that supports automotive functional safety applications up to ASIL-D and has advantages in power loss.

STMicroelectronics today announced the launch of the STPM801, the industry’s first automotive-qualified integrated hot-swap and ideal-diode controller to support functional safety applications.

Ideal-diode controllers drive external MOSFETs instead of Schottky diodes, which are commonly used for reverse input protection and output voltage holdup.

It reduces power loss during normal operation compared to the forward voltage of a Schottky diode by reducing the voltage drop across the MOSFET.

When a reverse voltage event occurs, such as a power failure, brownout, or input short-circuit, the MOSFET is turned off to block reverse current transients.

Additionally, the ideal-diode controller circuit provides power ORing to support switching between the main and backup batteries to ensure uninterrupted power supply to safety-critical equipment such as autonomous driving and ADAS.<br />
An integrated hot-swap controller drives a secondary-side external N-channel MOSFET to protect the load during a hot-swap event.

The soft-start feature charges a capacitor of the corresponding value connected to the gate at a constant current to prevent high inrush current, which controls the turn-on transient of the secondary MOSFET, and the overvoltage and undervoltage pins shut down the output voltage whenever the input voltage exceeds a specified threshold.

Additionally, the STPM801 features protection and monitoring features suitable for system applications that must meet functional safety requirements up to Automotive Safety Integrity Level (ASIL) D according to ISO 26262.

These features are packaged in a 5 mm x 5 mm VFQFN-32 footprint, reducing PCB space and minimizing the number of external components required.

The STPM801 operates with 25µA of standby current at supply voltages from 4V to 65V, minimizing battery drain when the vehicle is turned off and providing immunity to electrical hazards in the automotive environment.

Additionally, this product can be used in zone and body ECUs, ADAS ECUs, high-performance computing ECUs, infotainment ECUs, redundant power distribution systems, and dual battery systems.