ATA6621 ATMEL Corporation, ATA6621 Datasheet - Page 7

• Manufacturer Part Number: ATA6621
• Manufacturer: ATMEL Corporation

ATA6621
In Silent Mode, the 5V regulator is in low tolerance mode (4.65V to 5.35V) and can source up to
50 mA. The internal slave termination between pin LIN and pin VS is disabled to minimize the
power dissipation in case pin LIN is shorted to GND. Only a weak pull-up current (typically
10 µA) between pin LIN and pin VS is present.
The Silent Mode voltage tolerance is sufficient to run the internal timers of the microcontroller.
The undervoltage reset is now V
< 4.4V. If an undervoltage condition occurs, the NRES is
ccthS
switched to low and the ATA6621 changes state to Pre Normal Mode.
A falling edge at pin LIN followed by a dominant bus level maintained for a certain time period
(T
) results in a remote wake-up request. The device switches from Silent Mode to Pre Normal
bus
Mode. The internal LIN slave termination resistor is switched on. The remote wake-up request is
indicated by a low level at pin RXD to interrupt the microcontroller.
(Figure 3-5 on page
10)
With EN high, you can switch directly from Silent Mode to Normal Mode.
Figure 3-2.
Switch to Silent Mode
Sleep Mode
EN
Mode Select window
TXD
T
= 3.2 µs
d
NRES
VCC
Delay time Sleep Mode
T
_sleep = maximum 20 µs
d
LIN
LIN switches directly to recessive mode
7
4887B–AUTO–01/06