Manual

5
9146E–AUTO–03/11
Atmel ATA6663/ATA6664
The internal termination between pin LIN and pin V
S
is disabled. Only a weak pull-up
current (typical 10 µA) between pin LIN and pin V
S
is present. Sleep mode can be
activated independently from the actual level on pin LIN or WAKE.
3. Fail-safe Mode
At system power-up or after a wake-up event, the device automatically switches to
fail-safe mode. It switches the INH pin to a high state, to the V
S
level when VS
exceeds 5V. LIN communication is switched off. The microcontroller of the application
will then confirm normal mode by setting the EN pin to high.
Figure 3-1. Modes of Operation
Wake-up events from sleep mode:
•LIN bus
•EN pin
• WAKE pin
• VS undervoltage
Figure 3-1 on page 5, Figure 3-2 on page 6 and Figure 3-5 on page 8 show the details of
wake-up operations.
Fail-safe Mode
Communication: OFF
RXD: see table of Modes
INH: high (INH HS switch ON) if VS > 5V
a
Sleep Mode
INH: high impedance (INH HS switch OFF)
Communication: OFF
EN = 0
Go to sleep command
EN = 1
Local wake-up event
a: Power-up (V
S
> 3V)
b: V
S
< 5V
c: Bus wake-up event
d: Wake-up from wake switch
b
EN = 1
& NOT b
b
c or d
Normal Mode
INH: high (INH HS switch ON)
Communication: ON
Power-up
Table 3-1. Table of Operation Modes
Mode of Operation Transceiver INH RXD LIN
Fail-safe Off
On, except
VS < 5V
High, except after
wake-up
Recessive
Normal On On LIN depending TXD depending
Sleep Off Off High ohmic Recessive