ATA6620N ATMEL Corporation, ATA6620N Datasheet - Page 6

• Manufacturer Part Number: ATA6620N
• Manufacturer: ATMEL Corporation

4.2
4.2.1
6
Modes of Reduced Current Consumption
ATA6620N
Silent Mode
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 ATA6620N 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 and a high level at
pin
With EN high, ATA6620N switches directly from Silent- via Pre-normal to Normal mode.
Figure 4-2.
VSsi
VCCs
bus
TXD(Figure 4-3 on page
) results in a remote wake-up request. The device switches from Silent mode to Pre-normal
= 40 µA with no load at the V
.
NRES
VCC
TXD
EN
LIN
Normal Mode
Switch to Silent Mode
t
d
= 3.2 µs
7).
CC
Batt
Delay time silent mode
t
d_sleep
regulator.
is the result of 40 µA plus the V
LIN switches directly to recessive mode
= maximum 20 µs
Mode select window
(Figure 4-2 on page
CCthS
< 4.4V. If an undervoltage condition
6). For EN and TXD either two
Silent Mode
CC
regulator output current
Batt
4850H–AUTO–12/07
is typically