ATA6625 ATMEL Corporation, ATA6625 Datasheet - Page 9

• Manufacturer Part Number: ATA6625
• Description: (ATA6623 / ATA6625) LIN Bus Transceiver
• Manufacturer: ATMEL Corporation

4.4
4.5
4957F–AUTO–02/08
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Fail-safe Mode
Unpowered Mode
Figure 4-5.
At system power-up the device automatically switches to Fail-safe Mode. The voltage regulator
is switched on (V
to low for t
The IC stays in this mode until EN is switched to high, and changes then to the Normal Mode. A
power down of V
Mode after power up. A logic low at NRES switches the IC into Fail-safe Mode directly.
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.
NRES is low for the reset time delay t
regulator
LIN bus
voltage
NRES
RXD
VCC
EN
res
= 4 ms and gives a reset to the microcontroller. LIN communication is switched off.
LIN Wake-up Diagram from Sleep Mode
CC
Batt
Bus wake-up filtering time
= 3.3V/5V/50 mA), (see
(V
Low or floating
Low or floating
S
< 4V) during Silent- or Sleep Mode switches the IC into the Fail-safe
t
th
bus
Off state
, the IC mode changes from Unpowered Mode to Fail-safe Mode.
Reset
Figure 6-1 on page
; no mode change is possible during this time.
Figure 6-1 on page
Reset
time
Regulator wake-up time
Fail-safe Mode
VCC
11). After VS is higher than the VS
ATA6623/ATA6625
start-up time delay
Low
On state
. This time, t
Microcontroller
11). The NRES output switches
VCC
, depends on the
EN High
Normal Mode
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