E910.54B37AB ELMOS Semiconductor, E910.54B37AB Datasheet - Page 21

• Manufacturer Part Number: E910.54B37AB
• Description: Interface - Specialized FlexRay Transceiver
• Manufacturer: ELMOS Semiconductor

Specifications of E910.54B37AB

• Rohs: yes
• Product Type: FlexRay Transceiver
• Operating Supply Voltage: 5 V
• Supply Current: 50 mA
• Maximum Power Dissipation: 150 mW
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Package / Case: TSSOP-14
• Minimum Operating Temperature: - 40 C

4.2.6.4 bus failure detection methods
Figure 14: Possible bus failures
Fig. 14 shows the simplified diagrams of several failures of the bus lines (short circuits BP, BM to ground BP2GND,
BM2GND, or to Vsupply BP2VSUP, BM2VSUP as well as bus loads which are too low or too high).The error flags are
stored in the error register. Its value is read by the host microcontroller via SPI (see chapter 4.3.4).
The bus failure detection needs transmitted frames. It starts with the beginning of the transmission and it is real-
ized within a certain number of frames sent by the transmitter. The failure detection procedure depends on the
length of the Data_0 and Data_1 sequences, the resistances of the short circuits and the values of the stray induct-
ances of common mode chokes. Large stray inductances (a few 100nH until 1µH) may prevent to recognize the
bus voltages uBP and uBM during the bit times. Thus several FlexRay frames are necessary to get a valid result of
the measurement. High supply voltages and very low short circuit resistances may prevent to distinguish between
BP2VSUP and BM2VSUP exactly.
Furthermore, a ground shift between the nodes may be recognized as short circuit, especially if the transmitter
needs a longer time to set the common mode bus voltage to its steady state value. This may occur if a split termi-
nation with capacitors in the range of nF is used.
ELMOS Semiconductor AG
VCC/2
VCC
Short cut BM
BM
BP
Failure Detection
RxD=1
to GND
BM
BP
BM
BP
Short cut BP
to GND
RxD=0
BP
BM
Short cut BP
to VSupply
RxD=1
Data sheet
21/28
BM
BP
Short cut BM
to Vsupply
RxD=0
BM
BP
low or shortcut
perfomance or
R
DCLOAD
Reduced
BP-BM
QM-No.: 25DS0004.00 2010-02-03
idle
too
BM
BP
R
high or open
DCLOAD
load
too
E910.54