ATA6621 ATMEL Corporation, ATA6621 Datasheet - Page 8

• Manufacturer Part Number: ATA6621
• Manufacturer: ATMEL Corporation

3.12.3
8
ATA6621
Sleep Mode
Figure 3-3.
A falling edge at EN while TXD is low switches the IC into Sleep Mode. The TXD Signal has to
be logic low during the Mode Select window
on page
In Sleep Mode the transmission path is disabled. Supply current from V
I
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.
A falling edge at pin LIN followed by a dominant bus level maintained for a certain time period
(T
Mode. 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 pin RXD to interrupt the microcon-
troller.
With EN high you can switch directly from Silent Mode to Normal Mode. In the application where
the ATA6621 supplies the microcontroller, wake-up from Sleep Mode is only possible via LIN or
pin WAKE.
VSsleep
bus
Regulator
LIN bus
Voltage
) results in a remote wake-up request. The device switches from Sleep Mode to Pre Normal
NRES
RXD
VCC
(Figure 3-5 on page
= 10 µA. The V
EN
6.
If undervoltage, switch to Prenormal Mode
LIN Wake-up Waveform Diagram (from Silent Mode)
Node In Silent Mode
Silent Mode 4.5V to 5.5V/50 mA
Bus wake-up filtering time
CC
regulator is switched off. NRES and RXD are low. The internal slave
High
10)
T
bus
Regulator Wake-up time
(Figure 3-4 on page
Pre normal Mode 5V/50 mA
Pre Normal Mode
Undervoltage detection active
Low
9), see section
Normal Mode
Bat
4887B–AUTO–01/06
5V/50 mA
“Silent Mode”
Normal Mode
EN High
High
is typically