ata6663 ATMEL Corporation, ata6663 Datasheet - Page 8

• Manufacturer Part Number: ata6663
• Description: Lin Transceiver
• Manufacturer: ATMEL Corporation

3.13
3.14
8
Wake-up Source Recognition
Local Wake-up via Pin WAKE
Atmel ATA6663/ATA6664
A falling edge at pin WAKE, followed by a low level maintained for a certain time period
(t
that no transient creates a wake-up. The device then switches to fail-safe mode. Pin INH is
activated (switches to V
wake-up request is indicated both by a low level at pin RXD to interrupt the microcontroller and
by a strong pull-down at pin TXD (see
is 3V below the VS voltage with an output current of typically –3µA. Even in case of a continu-
ous low at pin WAKE it is possible to switch the IC into sleep mode via a low level at pin EN.
The IC will remain in sleep mode for an unlimited time. To generate a new wake-up at pin
WAKE, a high signal > 6 µs is required. A negative edge then starts the wake-up filtering time
again.
Figure 3-5.
The device can distinguish between a local wake-up request (pin WAKE) and a remote
wake-up request (LIN bus). The wake-up source can be read at pin TXD in fail-safe mode. If
an external pull-up resistor (typically 5k ) has been added on pin TXD to the power supply of
the microcontroller, a high level indicates a remote wake-up request (weak pull-down at pin
TXD), a low level indicates a local wake-up request (strong pull-down at pin TXD).
The wake-up request flag (indicated at pin RXD) as well as the wake-up source flag (indicated
at pin TXD) are reset immediately if the microcontroller sets pin EN to high (see
page 6
Wake pin
WAKE
regulator
Voltage
RXD
TXD
INH
EN
), results in a local wake-up request. According to ISO7637, the wake-up time ensures
and
Figure 3-5 on page
Wake-up from Wake-up Switch
TXD weak pull-down resistor
Node in sleep state
High or floating
Low or floating
Off state
S
) and the internal termination resistor is switched on. The local
Wake filtering time
8).
State change
t
WAKE
Figure
3-5). The voltage threshold for a wake-up signal
Regulator wake-up time delay
Microcontroller start-up
TXD strong pull-down
delay time
On state
High
Low
9146D–AUTO–09/10
Figure 3-2 on
pull-down
operation
EN High
Node in
High
Weak