Enhanced FlexRay Standard Transceiver
1 General Description
The AS8222 is a high-speed fault tolerant device operating as
interface between a generic FlexRay Communication Controller and
the copper wiring.
This device is the first FlexRay certified Transceiver for temperature
ranges up to 150°C ambient temperature. For bare-die deliveries
please contact ams for more information.
The AS8222 is designed to extend the application range for high
speed and safety critical time triggered bus systems in an
automotive environment. The bus driver is protected against short
circuits to the supply and GND. The AS8222 operates at baudrates
up to 10 Mbps and is fully conforming to the FlexRay Electrical
Physical Layer Specification V2.1 Rev B.
The AS8222 provides a host controller interface consisting of Enable
(EN) and Standby (STBN) input pins for mode handling by the
microcontroller and the Error (ERRN) output pin, signalling failures
and status information.
The device supports the NORMAL mode with activated FlexRay bus
transmitter and receiver, the RECEIVE_ONLY mode with activated
receiver only to avoid unwanted disturbances while listening to the
communication and the low-power modes STANDBY and SLEEP
with very low power consumption.
In case of undervoltage at one of the supply voltages (VBAT, VCC,
and VIO) the device will change its mode to a low-power mode
(either STANDBY or SLEEP mode) and the device will signal an
error accordingly. In case of low voltage is detected on both VBAT
and VCC the device will enter the POWER-OFF mode.
Ensuring application in safety critical environments a two wire bus-
guardian interface is implemented where additional redundant
circuitries on the electronic-control-unit can monitor the
communication on the receive enable output (RxEN) and can
activate and deactivate through the bus guardian enable input (BGE)
the transmitter. Additionally in low-power modes the wake conditions
at the RxEN pin can be monitored.
A thermal sensor circuit with an integral shutdown mechanism
prevents damage to the device in extreme temperature conditions.
2 Key Features
Data transfer up to 10 Mbps
Compliant with FlexRay Electrical Physical Layer Specification
V2.1 Rev. B
Wide operating ambient temperature range -40°C to +150°C
Excellent EMC performance
High common mode range insures excellent EMI immunity
Interface with optional bus guardian for bus supervision
Automatic thermal shutdown protection
Supports 12, 24V systems with low sleep current consumption
Integrated power management system
Two INH pins for the external voltage regulators control
Local wake-up input
Remote wake-up capability via FlexRay bus in sleep mode
Supports 2.5, 3, 3.3, 5 V microcontrollers and automatically
adapts to interface levels
Does not disturb the bus line if not powered
Protected against damage due to short circuit conditions on the
bus (positive and negative battery voltage)
Small Pb-free package: SSOP-20
Automotive qualified to AEC-Q100, grade 0
For bare-die deliveries please contact us.
The AS8222 FlexRay Standard Transceiver is best fitting for
automotive FlexRay nodes where bus wake-up and voltage regulator
control for voltage supplies is needed.
The device addresses all ECUs connected to the permanent battery
supply (terminal 30).
The device is best suited for high temperature applications with up to
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