The E981.08 manages the connection and communication between a microcontroller unit (MCU) and up to twelve sensor satellites. It can be applied for example in a vehicle passenger restraint system. The device provides four independently operating channels. Every channel manages the communication with a maximum of three sensor satellites.
Each channel supplies the sensor devices connected with a regulated DC voltage, which is derived from an external source. Sensor data are extracted by measuring the current, modulated by the connected sensor devices and provided to the MCU via SPI interface. The current threshold is adapted to the quiescent current of the system. The data bits are coded using a Manchester format. The device operates with an external 4MHz/8MHz clock.