6 Redundancy in the Isolated Bias Power Supply Architecture

Functional safety is an important topic in the automotive industry. To make the whole system more reliable, redundancy in the isolated bias power supply can be provided. This means that isolated bias supplies are getting power from both high-voltage and low-voltage batteries. Figure 6-1 shows the bias power supply architecture including redundant power supply form high voltage battery.

Figure 6-1 Centralized Architecture Using Single Isolated Bias Power Devices

Redundancy can be provided either to all devices or only to the low-side or high-side devices depending on the safety requirements. In the redundant architecture, in case of a failure either from low-voltage or high-voltage batteries, all the gate drivers are still powered from the other battery. In general, the gate drivers are primarily powered using the low-voltage battery. Whereas, the high-voltage battery is used to provide redundancy. A redundant architecture has better reliability from the functional safety point of view but the design adds additional cost in the system. The devices mentioned in High-Voltage Isolated Bias Power Supply are an excellent choice to provide redundancy from a high-voltage battery.