MUNICH, Germany Independently from each other, Austriamicrosystems (AMS) and NXP have expanded their FlexRay transceiver spectrum. In addition, there are hints that production start for more FlexRay-equipped vehicles is imminent.
AMS announces a new basis transceiver chip (AS8220) as well as the AS8224 active hub. In addition, the known AS8221 transceiver which was available as an engineering sample for more than a year is about to enter volume production in the company's own fab.
According to AMS product manager Harald Gall, the new designs are optimized for minimum asymmetric delays. "These asymmetric delays turned out to be one of the most limiting parameters for the network layout," Gall said. For this reason, the company's design team focused on minimizing these delays, he claimed.
The active hub connects up to four FlexRay branches while regenerating the signal on the network. In addition, up to two devices can be combined to an eight-port hub. Each branch can be configured individually and performs a failure detection procedure.
The AS8220 and AS8221 transceivers differ in that they are designed for different ECU connection types while the 8220 addresses ECUs supplied with switched battery voltage via battery clamp 15 and / or switched clamp 30, the 8221 is designed for ECU connected to permanent battery supply via clamp 30.
NXP highlights the low electro-magnetic emission (EME) of its products. Without specifying it in detail, the company claims their new FlexRay transceivers are 'best in class' with respect to EME. In addition, the current offerings sport improved power-on reset behavior and an enhanced receiver circuit with higher RF immunity.
NXPs TJA1081 claims to lead the industry by supporting 60 nanoseconds bit time which would allow for longer cables between ECUs. The TJA1082 is NXPs first FlexRay transceiver to comply with the current FlexRay physical layer specification 2.1 Rev. B. However, AMS claims its products also comply with this version of the specification. In addition, the FlexRay consortium currently is already about to finalize the next version it is supposed to bear the version number 3.0 and is scheduled for end of the year. Then the chip manufacturers will have to adapt their designs accordingly.
The start of AMS' AS8221 volume production hints to another fact: Probably, there soon will be another OEM on the market with FlexRay-equipped vehicles. Hitherto, to our knowledge, only or at least predominantly BMW had cars on sale with FlexRay buses in it. BMW, however, is said to use NXP transceivers.