Rainbow Electronics ATA6662 - Manual (Page 4)

4
4916E–AUTO–02/07
ATA6662 [Preliminary]
3.7 Enable Input Pin (EN)
This pin controls the operation mode of the interface. If EN = 1, the interface is in normal mode,
with the transmission path from TXD to LIN and from LIN to Rx both active. A falling edge on EN
while TXD is already set to high, the device is switched to sleep mode and no transmission is
possible. In sleep mode, the LIN bus pin is connected to V
S
with a weak pull-up current source.
The device can transmit only after being woken up (see Section 3.8 , “Inhibit Output Pin (INH)” ).
During sleep mode the device is still supplied from the battery voltage. The supply current is typ-
ically 10 µA. The pin EN provides a pull-down resistor in order to force the transceiver into sleep
mode in case the pin is disconnected.
3.8 Inhibit Output Pin (INH)
This pin is used to control an external switchable voltage regulator having a wake-up input. The
inhibit pin provides an internal switch towards pin V
S
. If the device is in normal mode, the inhibit
high-side switch is turned on and the external voltage regulator is activated. When the device is
in sleep mode, the inhibit switch is turned off and disables the voltage regulator.
A wake-up event on the LIN bus or at pin WAKE will switch the INH pin to the V
S
level. After a
system power-up (V
S
rises from zero), the pin INH switches automatically to the V
S
level. The
R
DSon
of the high-side output is < 1 k
Ω
.
3.9 Wake-up Input Pin (WAKE)
This pin is a high-voltage input used to wake the device up from sleep mode. It is usually con-
nected to an external switch in the application to generate a local wake-up. If you do not need a
local wake-up in your application, connect pin WAKE directly to pin VS. A pull-up current source
with typically –10 µA is implemented. The voltage threshold for a wake-up signal is 3V below the
VS voltage with an output current of typically –3 µA.
Wake-up events from sleep mode:
• LIN bus
• EN pin
• WAKE pin
Figure 3-1 on page 6 , Figure 3-2 on page 7 and Figure 3-3 on page 7 show details of wake-up
operations.