FUNCTIONAL DEVICE OPERATION
PROTECTION AND DIAGNOSIS FEATURES
Table 5. Explanation of Operational and Transitional Modes State Diagram
Operational/
LIN
INH
EN
TXD
RXD
Transitional
Recessive state, driver off.
High impedance.
Sleep Mode
LOW
LOW
X
20 µA pullup current source.
Recessive state, driver off.
LOW.
Awake
HIGH
HIGH
LOW
HIGH
X
Driver active. 30 kΩ pullupactive.
LOW to drive LIN bus in
dominant.
Report LIN bus level:
• LOW LIN bus dominant
• HIGH LIN bus recessive
Normal Mode
HIGH to drive LIN bus in
recessive.
X = Don’t care.
PROTECTION AND DIAGNOSIS FEATURES
ELECTROSTATIC DISCHARGE (ESD)
The 33399 has two Human Body Model ESD values. All
pins can handle ±4.0 kV. The LIN bus pin, with respect to
ground, can handle ±5.0 kV.
ELECTROMAGNETIC COMPATIBILITY
On the WAKE input pin, an internal filter is implemented to
reduce false wake-up during external disturbance.
RADIATED EMISSION ON LIN BUS OUTPUT LINE
Radiated emission level on the LIN bus output line is
internally limited and reduced by active slew rate control of
the output bus driver. Figure 11 shows the results in the
frequency range 100 kHz to 2.0 MHz.
NOISE FILTERING
Noise filtering is used to protect the electronic module
against illegal wake-up spikes on the bus. Integrated receiver
filters suppress any high-frequency (HF) noise induced into
the bus wires. The cut-off frequency of these filters is a
compromise between propagation delay and HF
suppression.
ELECTROMAGNETIC IMMUNITY (EMI)
On the LIN bus pin, the 33399 offers high EMI level from
external disturbance occurring at the LIN bus pin in order to
guarantee communication during external disturbance.
Figure 11. Radiated Emission in Normal Mode
33399
Analog Integrated Circuit Device Data
Freescale Semiconductor
13
FREESCALE [ Freescale ]
