Datasheet

TJA1028 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
Product data sheet Rev. 4 — 25 July 2012 5 of 24
NXP Semiconductors
TJA1028
LIN transceiver with integrated voltage regulator
The TJA1028T/xxx/20 and TJA1028TK/xxx/20 versions are optimized for a transmission
speed of 20 kBd, the maximum specified in the LIN standard. The TJA1028T/xxx/10 and
TJA1028TK/xxx/10 versions are optimized for a transmission speed of 10.4 kBd, as
specified in SAE J2602. All versions achieve optimum ElectroMagnetic Compatibility
(EMC) performance by wave shaping the LIN output.
7.1 LIN 2.x/SAE J2602 compliant
The TJA1028 is fully LIN 2.0, LIN 2.1, LIN 2.2 and SAE J2602 compliant. Since the LIN
physical layer is independent of higher OSI model layers (e.g. the LIN protocol), nodes
containing a LIN 2.2-compliant physical layer can be combined, without restriction, with
LIN physical layer nodes that comply with earlier revisions (i.e. LIN 1.0, LIN 1.1, LIN 1.2,
LIN 1.3, LIN 2.0 and LIN 2.1).
7.2 Operating modes
The TJA1028 supports four operating modes: Normal, Standby, Sleep and Off. The
operating modes, and the transitions between modes, are illustrated in Figure 3
.
(1) In Normal mode, the LIN transmitter is enabled - but if EN and/or RSTN go LOW, the LIN
transmitter will be disabled. Remote wake-up signalling will be activated.
(2) Until V
CC
drops below 2 V.
(3) If a wake-up event and a go-to-sleep event occur simultaneously, the device will switch directly to
Standby mode without initiating a reset.
Fig 3. State diagram
NORMAL
(1)
LIN = on
STANDBY
LIN = off
(RXD signals
wake source)
AII states
OFF
LIN = off
RXD = floating
RSTN = LOW
V
BAT
> V
th(det)pon AND
T
vj
< T
th(rel)otp
Voltage regulator - on
Voltage regulator
- off
wake-up
(3)
event
015aaa086
EN = 1 AND
RSTN = 1
EN = 1 0 AND
(3)
TXD = 0 AND
RSTN = 1
EN = 1
EN = 1 0 AND
TXD = 1 AND
RSTN = 1
V
BAT
< V
th(det)poff
OR
T
vj
> T
th(act)otp
SLEEP
LIN = off
RXD = V
CC
(2)
RSTN = LOW
remote
wake-up