Alexis Huot-Marchand

Bandgap circuitry with high immunity to harsh EMC disturbances

This work evaluates the susceptibility of a bandgap voltage reference to high electromagnetic interference superimposed at direct power injection on power supply and the majority carriers injection on substrate phenomena (typically observed during Bulk Current Injection, BCI). The investigation shows the significant impact of input pair of OTA, and the isolation connection of components on voltage reference in a high disturbance automotive environment. When isolation layer of a device is connected to power supply to increase substrate injection immunity, DPI performance during supply pin injection (PSDPI) is highly degraded. On the other hand, to increase Power Supply Immunity (PSI), it would be better to remove the isolation layer connected to power supply; this results in the Substrate Injection immunity decrease. A good compromise between Power injection and substrate injection performance for this bandgap circuitry is introduced and illustrated with optimisations.