ATA6620 ATMEL Corporation, ATA6620 Datasheet - Page 5

• Manufacturer Part Number: ATA6620
• Manufacturer: ATMEL Corporation

4.1
4.2
4850A–AUTO–02/05
Normal Mode
Silent Mode
Table 4-1.
This is the normal transmitting and receiving mode of the LIN Interface, in accordance with LIN
specification 2.0. The V
ance of ±2% and a maximum output current of 50 mA.
If an undervoltage condition occurs, NRES is switched to low and the ATA6620 changes state to
Pre-normal mode. All features are available.
A falling edge at EN while TXD is high switches the IC into Silent mode. The TXD Signal has to
be logic high during the Mode Select window
independent outputs can be used, or two outputs from the same microcontroller port; in the sec-
ond case, the mode change is only one command.
In Silent mode the transmission path is disabled. Supply current from V
I
The overall supply current from V
I
The 5V regulator is in low tolerance mode (4.65V to 5.35V) and can source up to 50 mA. In
Silent mode the internal slave termination between pin LIN and pin VS is disabled to minimize
the power dissipation in case pin LIN is short-circuited to GND. Only a weak pull-up current (typ-
ically 10 µA) between pin LIN and pin VS is present.
The Silent mode voltage is sufficient to run an external microcontroller on the ECU, for example
in Power Down mode. The undervoltage reset is V
occurs, NRES is switched to low and the ATA6620 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
mode, then 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.
page
With EN high, ATA6620 switches directly from Silent to Normal mode.
VSsi
VCCs
bus
= 40 µA with no load at the V
) results in a remote wake-up request. The device switches from Silent mode to Pre-normal
Pre-normal
.
Operation
8)
Mode of
Normal
Sleep
Silent
Mode of Operation
CC
Communication
voltage regulator operates with a 5V output voltage, with a low toler-
OFF
OFF
OFF
ON
CC
Batt
regulator.
is the result of 40 µA plus the V
(Figure 4-2 on page
V
5V
5V
5V
0V
ATA6620 [Preliminary]
CC
CCthS
< 4.4V. If an undervoltage condition
RXD
6). For EN and TXD either two
5V
5V
0V
5V
CC
regulator output current
Batt
Recessive
Recessive
Recessive
Recessive
(Figure 4-5 on
LIN
is typically
5