ATA6622 ATMEL Corporation, ATA6622 Datasheet - Page 10

• Manufacturer Part Number: ATA6622
• Description: LIN Bus Transceiver with 3.3V (5V) Regulator and Watchdog
• Manufacturer: ATMEL Corporation

4.4
4.5
10
Fail-safe Mode
Unpowered Mode
ATA6622/ATA6624/ATA6626 [Preliminary]
The VCC regulator is activated, and the internal LIN slave termination resistor is switched on.
The remote wake-up request is indicated by a low level at the RXD pin to interrupt the microcon-
troller (see
EN high can be used to switch directly from Sleep/Silent to Fail-safe Mode. If EN is still high after
VCC ramp up and undervoltage reset time, the IC switches to the Normal Mode.
Figure 4-4.
The device automatically switches to Fail-safe Mode at system power-up. The voltage regulator
is switched on (VCC = 3.3V/5V/2%/50 mA) (see
switches to low for t
switched off. The IC stays in this mode until EN is switched to high. The IC then changes to Nor-
mal Mode. A power down of V
Fail-safe Mode after power up. A low at NRES switches into Fail-safe Mode directly. During
Fail-safe Mode the TXD pin is an output and signals the last wake-up source.
If you connect battery voltage to the application circuit, the voltage at the VS pin increases
according to the block capacitor (see
undervoltage threshold VS
The VCC output voltage reaches its nominal value after t
VCC capacitor and the load.
The NRES is low for the reset time delay t
possible.
NRES
VCC
TXD
Figure 4-5 on page
LIN
EN
Switch to Sleep Mode
Normal Mode
res
= 4 ms and gives a reset to the microcontroller. LIN communication is
th
, the IC mode changes from Unpowered Mode to Fail-safe Mode.
11).
Batt
t
LIN switches directly to recessive mode
d_sleep
(V
Delay time sleep mode
t
d
S
= 3.2 µs
Figure 5-1 on page
< 4V) during Silent or Sleep Mode switches the IC into
Mode select window
= maximum 20 µs
reset
DRAFT
. During this time, t
Figure 5-1 on page
VCC
14). After VS is higher than the VS
. This time, t
Sleep Mode
reset
14). The NRES output
, no mode change is
VCC
, depends on the
4986B–AUTO–07/07