Philips Semiconductors
Product specification
LIN transceiver
TJA1020
FUNCTIONAL DESCRIPTION
The TJA1020 is the interface between the LIN master/slave protocol controller and the physical bus in a Local
Interconnect Network (LIN). The LIN transceiver is optimized for the maximum specified LIN transmission speed of
20 Kbaud providing optimum EMC performance due to wave shaping of the LIN output.
Operating modes
The TJA1020 provides two modes of normal operation, one intermediate mode and one very low power mode. Figure 3
shows the state diagram.
handbook, full pagewidth
NORMAL
SLOPE MODE
t
> t
(NSLP = 1; after 0−>1) gotonorm
STANDBY
and TXD = 1
INH = HIGH
TERM. = 30 kΩ
RXD = LOW
trx OFF
INH = HIGH
TERM. = 30 kΩ
RXD = LINDATA
trx ON
(t
> t
(NWAKE = 0; after 1−>0) NWAKE
or
t
> t
)
(LIN = 0; after 1−>0) BUS
and NSLP = 0
t
(NSLP = 0; after 1−>0)
> t
t
> t
gotosleep
t
> t
(NSLP = 1; after 0−>1) gotonorm
(NSLP = 1; after 0−>1) gotonorm
and no
wake-up event
and TXD = 0
and TXD = 1
SLEEP
LOW
SLOPE MODE
t
> t
(NSLP = 0; after 1−>0) gotosleep
INH = FLOATING
TERM. =
HIGH-OHMIC
and no wake-up event
INH = HIGH
TERM. = 30 kΩ
RXD = LINDATA
trx ON
RXD = FLOATING
trx OFF
t
> t
(NSLP = 1; after 0−>1) gotonorm
switching on BAT
and TXD = 0
MGU243
trx: transmitter.
TERM.: slave termination resistor, connected between pins LIN and BAT.
Fig.3 State diagram.
2002 Jul 17
4
NXP [ NXP ]
