Analog Integrated Circuit Device Data



26

Freescale Semiconductor

33663

FUNCTIONAL DESCRIPTION

FUNCTIONAL PIN DESCRIPTION

As soon as the device enters Normal mode, the LIN transmitter will be able to send the first dominant bit only after the

Normal mode.

Receiver Characteristics

The receiver thresholds are ratiometric with the device supply pin.

state even if communication is sent to TXD1 or TXD2.

For the LIN Module 1, in case of LIN1 Thermal Shutdown, the transceiver and receiver are in recessive and INH1 turned off.

Module 2.

For each LIN Module, the Fast Baud Rate selection is reported by the RXD pin. Fast Baud Rate is activated by the toggle

Baud Rate entry (See Figure 19).

To exit the Fast Baud Rate and return in Normal or Slow baud rate, a toggle function is needed. At the end the toggle function,

RXD pin stays high to signal Fast Baud Rate exit (See Figure 20). The device enters into Fast Baud Rate at room and hot

temperature.

DATA INPUT PINS (TXD1, TXD2)

The TXD1 and TXD2 inputs pins are the MCU interface to control the state of the LIN1 and LIN2 outputs. When TXD1 (TXD2)

is LOW (dominant), LIN1 (LIN2) output is LOW; when TXD1 (TXD2) is HIGH (recessive), the LIN1 (LIN2) output transistor is

turned OFF. TXD1/TXD2 pins thresholds are 3.3 V and 5.0 V compatible.

These pins have an internal pull-up current source to force the recessive state if the input pins are left floating.

If TXD1 (TXD2) stays low (dominant sate) more than 5.0 ms (typical value), the LIN1 (LIN2) transmitter of LIN Module goes

automatically into recessive state.

DATA OUTPUT PINS (RXD1, RXD2)

Each LIN Modules integrate the same RXD output structure and functionality. Both pins are independent. The following

description is the same for both.

RXD output pin is the MCU interface, which reports the state of the LIN bus voltage.

In Normal or Slow baud rate, LIN HIGH (recessive) is reported by a high voltage on RXD; LIN LOW (dominant) is reported by

a low voltage on RXD. The RXD output structure is a tristate output buffer.

Figure 24. RXD interface

The RXD output pins are the receiver output of the LIN interface. The low level is fixed. The high level is dependent on EN

defined independently.

In sleep mode, RXD are high-impedance. When a wake-up event is recognized from the WAKE pin or from the LIN bus pin,

RXD is pulled LOW to report the wake-up event. An external pull-up resistor may be needed.

RXD

EN

200k



X1

EN_RXD

LIN

VSUP

Slope

Control

Receiver



30k

LIN_RXD