33661 Datasheet, PDF (15/21 Pages) Freescale Semiconductor, Inc – Local Area Network (LIN) Enhanced Physical Interface with Selectable Slew Rate

FUNCTIONAL DEVICE OPERATION
OPERATIONAL MODES
Power-Up
TXD HIGH and EN LOW to
HIGH
TXD HIGH and EN LOW > t_{1 (}35 µs)
Fast
(10 x)
Toggle Function _{EN LOW for t2 < 5.0 µs,}
then HIGH
LIN Bus or WAKE Pin
Wake-Up
Sleep
Awake
TXD HIGH and EN LOW to HIGH
Normal
1.0 to 20
kbps
EN LOW for t₂ < 5.0 µs,
then HIGH
TXD LOW and EN
LOW to HIGH
TXD LOW and EN LOW to HIGH
Wait Slow
TXD HIGH
Slow
1.0 to 10
kbps
EN LOW for t₂ < 5.0 µs,
then HIGH
TXD HIGH and EN LOW > t₁ (35 µs)
Toggle Function
Note Refer to Table 5 for explanation.
EN LOW for t₂ < 5.0 µs, then HIGH
Fast
(10 x)
Figure 15. Operational and Transitional Modes State Diagram
Table 5. Explanation of Operational and Transitional Modes State Diagram
Operational/
Transitional
Sleep Mode
Awake
Normal Mode
LIN
Recessive state, driver off.
20 µA pullup current source.
Recessive state, driver off.
30 kΩ pullup active.
Driver active. 30 kΩ pullup active.
Slew rate normal (20 kbps).
INH
LOW
HIGH
HIGH
Wait Slow
Slow
Recessive state. Driver off.
30 kΩ pullup active.
Driver active. 30 kΩ pullup active.
Slew rate slow (10 kbps).
HIGH
HIGH
Fast
Driver active. 30 kΩ pullup active. HIGH
Slew rate fast (> 100 kbps).
EN
TXD
RXD
LOW
LOW
HIGH
HIGH
X
High impedance. HIGH if external
pullup to V_DD.
X
LOW. If external pullup, HIGH-to-
LOW transition reports wake-up.
HIGH to enter Normal mode.
Once in Normal mode: LOW to
drive LIN bus in dominant, HIGH
to drive LIN bus in recessive.
Report LIN bus level:
• Low LIN bus dominant
• High LIN bus recessive
LOW
HIGH
HIGH
HIGH
LOW to enter Slow mode. Once
in Slow mode: LOW to drive LIN
bus in dominant, HIGH to drive
LIN bus in recessive.
Report LIN bus level:
• Low LIN bus dominant
• High LIN bus recessive
LOW to drive LIN bus in
Report LIN bus level:
dominant, HIGH to drive LIN bus • Low LIN bus dominant
in recessive.
• High LIN bus recessive
X = Don’t care.
ELECTROMAGNETIC COMPATIBILITY
RADIATED EMISSION IN NORMAL AND SLOW
MODES
The 33661 has been tested for radiated emission
performances. Figures 16 and 17 show the results in the
frequency range 100 kHz to 2.0 MHz. Test conditions are in
accordance with CISPR25 recommendations, bus length of
Analog Integrated Circuit Device Data
Freescale Semiconductor
33661
15