MC33662LEF Datasheet, PDF (21/31 Pages) Freescale Semiconductor, Inc – LIN 2.1 / SAEJ2602-2, LIN Physical Layer

FUNCTIONAL DESCRIPTION
INTRODUCTION
FUNCTIONAL DESCRIPTION
INTRODUCTION
The 33662L, 33662J, and 33662S are a physical layer
component dedicated to automotive LIN sub-bus
applications.
The 33662L and 33662S features include a 20 kbps baud
rate and the 33662J a 10 kbps baud rate. They integrate fast
baud rate for test and programming modes, excellent ESD
robustness, immunity against disturbance, and radiated
emission performance. They have safe behavior in case of a
LIN bus short-to-ground, or a LIN bus leakage during low
power mode.
Digital inputs are 5.0 and 3.3 V compatible without any
external required components.
The INH output can be used to control an external voltage
regulator, or to drive a LIN bus pull-up resistor.
FUNCTIONAL PIN DESCRIPTION
POWER SUPPLY PIN (VSUP)
The VSUP supply pin is the power supply pin for the
33662L, or 33662J, or 33662S. In an application, the pin is
connected to a battery through a serial diode, for reverse
battery protection. The DC operating voltage is from 7.0 to
18 V. This pin can sustain a standard automotive load dump
condition up to 40 V. To avoid a false bus message, an
undervoltage on VSUP disables the transmission path (from
TXD to LIN) when V_SUP falls below 6.7 V. Supply current in
Sleep mode is typically 6.0 A.
GROUND PIN (GND)
In case of a ground disconnection at the module level, the
33662L, 33662J, and 33662S do not have significant current
consumption on the LIN bus pin when in the recessive state.
LIN BUS PIN (LIN)
The LIN pin represents the single-wire bus transmitter and
receiver. It is suited for automotive bus systems, and is
compliant to the LIN bus specification 1.3, 2.0, 2.1, and
SAEJ2602-2.
The LIN interface is only active during Normal mode (See
Figure 27).
LIN overtemperature
INH overtemperature
OR
INH switched off &
LIN transmitter and receiver disabled
VSUP
LIN Wake up
VSUP Undervoltage
TXD Dominant
EN
X1
TXD
LIN Driver
Slope Control
35µA
INH_ON
EN_sleep
INH
30 k
725 k
LIN
RXD
Receiver
Figure 27. LIN Interface
Transmitter Characteristics
The LIN driver is a low side MOSFET with internal
overcurrent thermal shutdown. An internal pull-up resistor
with a serial diode structure is integrated so no external pull-
up components are required for the application in a slave
node. An additional pull-up resistor of 1.0 k must be added
when the device is used in the master node.
The LIN pin exhibits no reverse current from the LIN bus
line to V_SUP, even in the event of a GND shift or V_SUP
disconnection. The 33662 is tested according to the
application conditions (i.e. in normal mode and recessive
state during communication).
The transmitter has a 20 kbps baud rate (Normal baud
rate) for the 33662L and 33662S devices, or 10 kbps baud
rate (Slow baud rate) for the 33662J device. As soon as the
device enters in Normal mode, the LIN transmitter will be able
to send the first dominant bit only after the t_{FIRST_DOM} delay.
t_{FIRST_DOM} delay has no impact on the receiver. The receiver
will be enabled as soon as the device enters in Normal mode.
Analog Integrated Circuit Device Data
Freescale Semiconductor
33662
21