FlexRay™ StaR CoupleR
Features
ÿ
Part of the FlexRay™ electrical, physical layer
ÿ
Active star coupler connects up to
4
branches
(FlexRay™ busses) to nodes or other active stars
ÿ
Support of data rates up to
10
Mbit/s
ÿ
Optional support of low power mode for an ECU
ÿ
Remote wake up via bus line
ÿ
Enhanced diagnosis capability provided via SPI
with interrupt generation
ÿ
Protection against overload damage by current
limitation and overtemperature detection
ÿ
Bus driver outputs withstand -
27
V / +
40
V DC
voltage
ÿ
Low EME due to balanced differential transmission
E910.56
Brief Functional Description
The star coupler is part of the electrical, physical layer
in a FlexRay™ communication network. The
E910.56
provides interfaces to connect up to four branches of
twisted pair physical bus lines to other bus drivers or
star couplers. It also interfaces with a communication
controller (CC) and a µC. Via SPI the bus driver (BD) pro-
vides status information concerning failure detection
on the bus lines (e.g. short circuit, ground loss) and
overtemperature condition to a host controller (HOST).
An interrupt signal is generated whenever the failure
status changes.
The device supports normal and standby modes and
provides remote wake up capability via bus line. The
output (INH) can be used to control an external vol-
tage regulator.
applications
ÿ
Star coupler and additionally usable as transceiver
in FlexRay™ nodes (ECUs)
ELMOS is member of the FlexRay consortium
typical application
Blockdiagram
SCSN
SCK
SDI
SDO
INTN
Single_Branch_1
Host Interface
(SPI + Interrupt)
Bus Failure
Detector_1
VBAT
BP_1
Transmitter_1
Microcontroller
(HOST)
Communication
Controller
TxEN
SPI
INTN
TxD
RxD
VIO
Power
Supply
ECU 1
BM_1
RxD
TxD
TxEN
Communication
Controller Interface
Receiver_1
Wake up
Detector_1
4
VCC
INH
TRXD1
TRXD2
VBUF
Single_Branch_2
BP_2
BM_2
Local
Wakeup
LWU
BP_1
BM_1
BP_2
Bus Driver
E910.56
BM_2
BP_3
BM_3
BP_4
to additional
stars
....
Central
Logic
Single_Branch_3
....
BP_3
BM_3
BM_4
Single_Branch_4
....
INH
LWU
BP_4
BM_4
Inhibit & Wake
Star Transmitter &
Receiver
TRXD1
TRXD2
GND
VBAT
VCC
VIO
Power
Supply
5V Regulator
Undervolt.
Monitor
Overtemp.
Monitor
POR
Vref
VBUF
E910.56
GND
ELMOS Semiconductor AG
October
2007
ELMOS [ ELMOS SEMICONDUCTOR AG ]
