TLE9221SX Datasheet, PDF (9/91 Pages) Infineon Technologies AG – FlexRay Transceiver

TLE9221SX
Functional Overview
4
Functional Overview
4.1
Functional Description
FlexRay is a differential bus system. The data is exchanged via a dual wire bus medium on the wires BP (Bus Line
Plus) and BM (Bus Line Minus).
Three different bus symbols are defined in the FlexRay EPL, version 3.0.1: “Data_0”, “Data_1” and bus “Idle”. An
active Transmitter of the TLE9221SX drives “Data_0” or “Data_1” to the bus medium, depending on the TxD input
signal. To sustain an “Idle” signal on the FlexRay bus, the Transmitter is turned off, the voltage difference between
BP and BM is below 30 mV, and the absolute voltage level on both bus lines, BP and BM depends on the Bus
Biasing (see Figure 3):
• “Data_1”: uBus = uBP - uBM ≥ 300 mV → positive voltage between BP and BM
• “Data_0”: uBus = uBP - uBM ≤ - 300 mV → negative voltage between BP and BM
• “Idle”: |uBus| = |uBP - uBM| ≤ 30 mV
|
TxEN
t
TxD
BP
BM
“Data_1”
“Data_0”
V_BUS
“Data_1”
“Data_0”
“Data_1”
“Data_0”
“Idle”¹⁾
“Data_1”
“Data_0”
“Idle”¹⁾
t
“Idle”²⁾
t
“Idle”²⁾
t
RxD
t
1) Some nodes or all nodes inside the FlexRay Network are in BD_Normal mode.
2) All nodes of the FlexRay network are in low power mode.
Figure 3 FlexRay EPL bus signals without Bus Guardian Interface
Data Sheet
9
Rev. 1.10, 2013-07-15