Datasheet

DESCRIPTION
TERMINAL FUNCTIONS
1
2
3
4
8
7
6
5
RXD
EN
NWake
TXD
INH
V
SUP
LIN
GND
D PACKAGE
(TOP VIEW)
TPIC1021A-Q1
SLIS117A – AUGUST 2007 – REVISED JUNE 2009 .......................................................................................................................................................... www.ti.com
The TPIC1021A is the Local Interconnect Network (LIN) physical interface, which integrates the serial transceiver
with wake-up and protection features. The LIN bus is a single-wire bidirectional bus typically used for low-speed
in-vehicle networks using data rates between 2.4 kbps and 20 kbps. The LIN protocol output data stream on TXD
is converted by the TPIC1021A into the LIN bus signal through a current-limited wave-shaping driver as outlined
by the LIN Physical Layer Specification Revision 2.0. The receiver converts the data stream from the LIN bus
and outputs the data stream via RXD. The LIN bus has two states: dominant state (voltage near ground) and the
recessive state (voltage near battery). In the recessive state, the LIN bus is pulled high by the TPIC1021A ’ s
internal pullup resistor (30 k Ω ) and series diode, so no external pullup components are required for slave
applications. Master applications require an external pullup resistor (1 k Ω ) plus a series diode per the LIN
specification.
In sleep mode, the TPIC1021A requires low quiescent current even though the wake-up circuits remain active,
allowing for remote wake up via the LIN bus or local wake up via the NWake or EN pins.
The TPIC1021A has been designed for operation in the harsh automotive environment. The device can handle
LIN bus voltage swings from 40 V down to ground and survive – 40 V. The device also prevents back-feed
current through LIN to the supply input, in case of a ground shift or supply voltage disconnection. It also features
undervoltage, overtemperature, and loss-of-ground protection. In the event of a fault condition, the output is
immediately switched off and remains off until the fault condition is removed.
TERMINAL ASSIGNMENTS
PIN
TYPE DESCRIPTION
NAME NO.
RXD 1 O RXD output (open drain) interface reporting state of LIN bus voltage
EN 2 I Enable input
NWake 3 I High voltage input for device wake up
TXD 4 I TXD input interface to control state of LIN output
GND 5 GND Ground
LIN 6 I/O LIN bus single-wire transmitter and receiver
V
SUP
7 Supply Device supply voltage (connected to battery in series with external reverse blocking diode)
INH 8 O Inhibit controls external voltage regulator with inhibit input
ORDERING INFORMATION
(1)
PART NUMBER PACKAGE
(2)
ORDERABLE PART NUMBER TOP-SIDE MARKING
TPIC1021A-Q1 SOIC-8 – D TPIC1021AQDRQ1 (reel) T1021A
(1) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI
web site at www.ti.com .
(2) Package drawings, thermal data, and symbolization are available at www.ti.com/packaging .
2 Submit Documentation Feedback Copyright © 2007 – 2009, Texas Instruments Incorporated
Product Folder Link(s): TPIC1021A-Q1