Rainbow Electronics ATA6664 - Manual (Page 9)

9
9146E–AUTO–03/11
Atmel ATA6663/ATA6664
3.15 Fail-safe Features
• During a short-circuit at LIN to V
BAT
, the output limits the output current to IBUS_LIM. Due
to the power dissipation, the chip temperature exceeds T
off
, and the LIN output is switched
off. The chip cools down, and after a hysteresis of T
hys
, it switches the output on again.
• During a short-circuit from LIN to GND the IC can be switched to sleep mode, and even in
this case the current consumption is lower than 45µA. When the short-circuit has elapsed,
the IC starts with a remote wake-up.
• If the Atmel ® ATA6663/ATA6664 is in sleep mode and a floating condition occurs on the
bus, the IC switches back to sleep mode automatically. The current consumption is lower
than 45µA in this case.
• The reverse current is < 2µA at pin LIN during loss of V
BAT
. This is the best behavior for bus
systems where some slave nodes are supplied from battery or ignition.
• Pin EN provides a pull-down resistor to force the transceiver into sleep mode if EN is
disconnected
• Pin RXD is set floating if V
BAT
is disconnected
• Pin TXD provides a pull-down resistor to provide a static low if TXD is disconnected
• After switching the IC into Normal Mode the TXD pin must be pulled to high longer than
10µs in order to activate the LIN driver. This feature prevents the bus from being driven into
dominant state when the IC is switched into Normal Mode and TXD is low.
• The INH output transistor is protected by temperature monitoring