MC33662LEF Datasheet, PDF (23/31 Pages) Freescale Semiconductor, Inc – LIN 2.1 / SAEJ2602-2, LIN Physical Layer

WAKE INPUT PIN (WAKE)
The WAKE pin is a high voltage input used to wake-up the
device from the Sleep mode. WAKE is usually connected to
an external switch in the application.
The WAKE pin has a special design structure and allows
wake-up from both HIGH to LOW or LOW to HIGH
transitions. When entering into Sleep mode, the device
monitors the state of the WAKE pin and stores it as a
reference state. The opposite state of this reference state will
be the wake-up event used by the device to enter again into
Normal mode.
If the Wake pin state changes during the Sleep mode
Delay Time (t_SD) or before EN goes low with a deglitcher
FUNCTIONAL DESCRIPTION
FUNCTIONAL PIN DESCRIPTION
lower than t_WF, the device will not enter the Sleep mode, but
will go into Awake mode (See Figure 26).
An internal filter is implemented to avoid a false wake-up
event due to parasitic pulses (See Figure 15 and 18). WAKE
pin input structure exhibits a high-impedance, with extremely
low input current when voltage at this pin is below 27 V. Two
serial resistors should be inserted in order to limit the input
current mainly during transient pulses and ESD. The total
recommended resistor value is 33 k. An external 10 to
100 nF capacitor is advised for better EMC and ESD
performances.
Important The WAKE pin should not be left open. If the
wake-up function is not used, WAKE should be connected to
ground to avoid a false wake-up.
Analog Integrated Circuit Device Data
Freescale Semiconductor
33662
23