Analog Integrated Circuit Device Data

Freescale Semiconductor

13

33399

FUNCTIONAL DEVICE OPERATION

PROTECTION AND DIAGNOSIS FEATURES

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

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.

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.

On the WAKE input pin, an internal filter is implemented to

reduce false wake-up during external disturbance.

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.

Figure 11. Radiated Emission in Normal Mode

Table 5. Explanation of Operational and Transitional Modes State Diagram

Operational/

Transitional

LIN

INH

EN

TXD

RXD

Sleep Mode

Recessive state, driver off.

20

µA pullup current source.

LOW

LOW

X

High impedance.

Awake

Recessive state, driver off.

HIGH

LOW

X

LOW.

Normal Mode

Driver active. 30 k

Ω pullup active.

HIGH

HIGH

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

X = Don’t care.