For new sensor generation, Hella relies on SENT protocol

MUNICH, Germany — Automotive tier one Hella KGaA (Lippstadt, Germany) has announced to develop a new generation of digital automotive sensors, based on the SENT (Single Edge Nibble Transmission) protocol. The first application, to be expected in fall 2009, will be a throttle position indicator.

Not in all cases, digital sensors need to be connected to "grown-up" data bus systems such as FlexRay, CAN or even the cost-effective and simple LIN bus. For cost reasons, in some case it is more desirable to connect sensors directly to a close-by electronic control unit (ECU). Throttle sensors, typically analog devices, in most cases feed their signals directly into an ECU across short distances.

The SENT protocol offers a possibility to digitize these data transmissions maintaining low costs. The protocol provides the transmission of four bits (a "nibble") at a time, using the trailing edge of the pulses to carry the information.

Hella has announced to make use of this protocol in its CIPOS (Contactless Inductive Position Sensor) product family which aims at path and angle measurements in the engine compartment. High temperatures and vibrations make measurements in this environment rather difficult.

SENT is the latest standard in automotive electronics. Its major advantage is the compact and simple assembly. SENT devices use a single wire for data transmission, and up to two signals can share a wire. Since the protocol sports low susceptibility against electromagnetic interference, shielded or twisted cables are not required.

The protocol provides a simple and cost-effective way to exchange sensor data. Hella announced to start volume production for its CIPOS sensor products in fall 2009.