ATA6662 ATMEL Corporation, ATA6662 Datasheet - Page 6

• Manufacturer Part Number: ATA6662
• Description: LIN Transceiver
• Manufacturer: ATMEL Corporation

3.13
3.14
6
Wake-up Source Recognition
Fail-safe Features
ATA6662 [Preliminary]
The device can distinguish between a local wake-up request (pin WAKE) and a remote wake-up
request (dominant LIN bus). The wake-up source can be read on pin TXD in pre-normal mode. If
an external pull-up resistor (typically 5 k ) has been added on pin TXD to the power supply of
the microcontroller, a high level indicates a remote wake-up request (weak pull-down at pin
TXD) and a low level indicates a local wake-up request (strong pull-down at pin TXD).
The wake-up request flag (signalled on pin RXD) as well as the wake-up source flag (signalled
on pin TXD) are reset immediately if the microcontroller sets pin EN to high (see
page 7
Figure 3-1.
• There are now reverse currents < 15 µA at pin LIN during loss of V
• Pin EN provides a pull-down resistor to force the transceiver into sleep mode if EN is
• Pin RXD is set floating if V
• Pin TXD provides a pull-down resistor to provide a static low if TXD is disconnected.
• The LIN output driver has a current limitation, and if the junction temperature T
• The implemented hysteresis, T
behavior for bus systems where some slave nodes are supplied from battery or ignition.
disconnected.
thermal shut-down temperature T
been decreased.
INH: high (INH HS switch ON)
and
Communication: ON
Figure 3-3 on page
Normal Mode
Mode of Operation
b
EN = 1
BAT
EN = 0; after 1
EN = 1
INH: high (INH internal high-side switch ON)
7).
is disconnected.
hys
off
, enables the LIN output again after the temperature has
Communication: OFF
, the output driver switches off.
Unpowered Mode
Go to sleep command
Pre-normal Mode
Local wake-up event
0 while TXD = 1
V
b
Batt
= 0V
a
d
c
INH: high impedance (INH HS switch OFF)
a: V
b: V
c: Bus wake-up event
d: Wake-up from wake switch
b
S
S
BAT
> 5V
< 5V
Communication: OFF
Sleep Mode
or GND; this is optimal
4916E–AUTO–02/07
j
Figure 3-2 on
exceeds the