TPIC1021
SLIS113E – OCTOBER 2004 – REVISED MAY 2022
TPIC1021 LIN Physical Interface
1 Features
3 Description
•
The TPIC1021 is the LIN (Local Interconnect
Network) physical interface, which integrates the
serial transceiver with wake up and protection
features. The LIN bus is a single wire, bi-directional
bus typically used for low-speed in-vehicle networks
using baud rates between 2.4 kbps and 20 kbps.
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
LIN physical layer specification revision 2.1
compliant conforms to SAEJ2602 recommended
practice for LIN
LIN bus speed up to 20 kbps
ESD protection to 12 kV (human body model) on
LIN pin
LIN pin handles voltage from –40 V to 40 V
Survives transient damage in automotive
environment (ISO 7637)
Operation with supply from 7-V to 27-V DC
Two operation modes: normal and low-power
(sleep) mode
Low current consumption in low power mode
Wake-up available from LIN bus, wake-up input
(external switch) or host MCU
Interfaces to MCU with 5-V or 3.3-V I/O pins
Dominant state timeout protection on TXD pin
Wake-up request on RXD pin
Control of external voltage regulator (INH Pin)
Integrated pull-up resistor and series diode for LIN
responder applications
Low EME (electromagnetic emissions), high EMI
(electromagnetic immunity)
Bus terminal short-circuit protected for short to
battery or short to ground
Thermally protected
Ground disconnection fail-safe at system level
Ground shift operation at system level
Unpowered node does not disturb the network
2 Applications
•
•
Industrial sensing
White goods distributed control
The LIN bus has two logical values: the dominant
state (voltage near ground) represents a logic 0
and the recessive state (voltage near battery) and
represents logic 1.
In the recessive state, the LIN bus is pulled high
by the TPIC1021 internal pull-up resistor (30 kΩ)
and series diode, so no external pullup components
are required for responder applications. Commander
applications require an external pullup resistor (1 kΩ)
plus a series diode.
Device Information
PART NUMBER
TPIC1021
(1)
PACKAGE(1)
BODY SIZE (NOM)
SOIC (8)
4.90 mm × 3.91 mm
For all available packages, see the orderable addendum at
the end of the data sheet.
8
7
1
RXD
Receiver
INH
VSUP
VSUP/2
2
EN
NWake
3
Wake−Up
and
Vreg Control
Filter
Dominant
State
Timeout
4
TXD
Filter
Fault
Detection and
Protection
6
LIN
5
Driver
GND
with Slope
Control
Functional Block Diagram
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
TPIC1021
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SLIS113E – OCTOBER 2004 – REVISED MAY 2022
Table of Contents
1 Features............................................................................1
2 Applications..................................................................... 1
3 Description.......................................................................1
4 Revision History.............................................................. 2
5 Description (continued).................................................. 3
6 Pin Configuration and Functions...................................3
7 Specifications.................................................................. 4
7.1 Absolute Maximum Ratings........................................ 4
7.2 ESD Ratings............................................................... 4
7.3 Recommended Operating Conditions.........................4
7.4 Thermal Information....................................................4
7.5 Electrical Characteristics.............................................5
7.6 Timing Requirements.................................................. 6
7.7 Typical Characteristics................................................ 7
8 Detailed Description........................................................8
8.1 Overview..................................................................... 8
8.2 Functional Block Diagram........................................... 8
8.3 Feature Description.....................................................8
8.4 Device Functional Modes..........................................10
9 Application and Implementation.................................. 13
9.1 Application Information............................................. 13
9.2 Typical Application.................................................... 13
9.3 Power Supply Recommendations.............................14
9.4 Layout....................................................................... 14
10 Device and Documentation Support..........................16
10.1 Receiving Notification of Documentation Updates..16
10.2 Support Resources................................................. 16
10.3 Trademarks............................................................. 16
10.4 Electrostatic Discharge Caution..............................16
10.5 Glossary..................................................................16
11 Mechanical, Packaging, and Orderable
Information.................................................................... 16
4 Revision History
Changes from Revision D (June 2015) to Revision E (May 2022)
Page
• Changed Feature From: "...Revision 2.0 compliant" To: "... Revision 2.1 compliant"......................................... 1
• Changed all instances of legacy terminology to commander and responder where mentioned.........................1
• Changed From: "LIN Physical Layer Specification Revision 2.0" To: "LIN Physical Layer Specification
Revision 2.1" in the Description (continued) ...................................................................................................... 3
• Added: (LIN 2.1 compatible) to Note 2 of the Timing Requirements ................................................................. 6
• Changed paragraph three in the Transmitter Characteristics section.................................................................8
• Changed three instances of "IHN" to "INH" in Figure 8-1 ................................................................................ 10
Changes from Revision C (July 2005) to Revision D (June 2015)
Page
• Added Pin Configuration and Functions section, ESD Ratings table, Feature Description section, Device
Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout
section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information
section ............................................................................................................................................................... 1
2
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5 Description (continued)
The LIN Protocol output data stream on the TXD pin is converted by the TPIC1021 into the LIN bus signal
through a current limited, wave-shaping low-side driver with control as outlined by the LIN Physical Layer
Specification Revision 2.1. The receiver converts the data stream from the LIN bus and outputs the data stream
via the RXD pin.
In Low Power mode, the TPIC1021 requires very low quiescent current even though the wake-up circuits remain
active allowing for remote wake up via the LIN bus or local wake ups via NWake or EN pins.
The TPIC1021 has been designed for operation in the harsh automotive environment. The device can handle
LIN bus voltage swing from 40 V down to ground and survive –40 V. The device also prevents back feed current
through the LIN pin to the supply input in case of a ground shift or supply voltage disconnection. It also features
under-voltage, over temperature, 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.
6 Pin Configuration and Functions
RXD
1
8
INH
ED
2
7
VSUP
NWake
3
6
LIN
TXD
4
5
GND
Not to scale
Figure 6-1. D Package, 8-Pin SOIC
Table 6-1. Pin Functions
PIN
NO.
NAME
TYPE
DESCRIPTION
1
RXD
O
RXD output (open drain) pin interface reporting state of LIN bus voltage
2
ED
I
Enable input pin
3
NWake
I
High voltage input pin for device wake up
4
TXD
I
TXD input pin interface to control state of LIN output
5
GND
I
Ground connection
6
LIN
I/O
7
VSUP
Supply
8
INH
O
LIN bus pin single wire transmitter and receiver
Device supply pin (connected to battery in series with external reverse blocking diode)
Inhibit pin controls external voltage regulator with inhibit input
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7 Specifications
7.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)(1)
VSUP (2)
Continuous
Supply line supply voltage
Transient
MIN
MAX
UNIT
0
27
V
0
40
V
–1
40
V
Logic pin input voltage (RXD, TXD, EN)
–0.3
5.5
V
LIN DC input voltage
–40
40
V
TA
Operational free-air temperature
–40
125
°C
TJ
Junction temperature
–40
150
°C
Thermal shutdown
200
°C
Thermal shutdown hysteresis
25
°C
165
°C
NWake DC and transient input voltage (through 33-kΩ serial resistor)
Tstg
(1)
(2)
Storage temperature range
–40
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only and functional operation of the device at these or any other conditions beyond those indicated under Section 7.3 is not implied.
Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
All voltage values are with respect to GND.
7.2 ESD Ratings
VALUE
Human body model (HBM), per ANSI/ESDA/JEDEC
JS-001(1) (2)
V(ESD)
Electrostatic discharge
Machine model(3)
(1)
(2)
(3)
LIN pin
±12000
NWake pin
±9000
All other pins
±3000
LIN and NWake pins
±400
All other pins
±200
UNIT
V
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
The human body model is a 100-pF capacitor discharged through a 1.5-kΩ resistor into each pin.
The machine model is a 200-pF capacitor through a 10-Ω resistor and a 0.75-µH coil.
7.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
MIN
TSUP
Supply voltage
TAMB
Ambient temperature
NOM
MAX
UNIT
7
27
V
–40
125
°C
7.4 Thermal Information
TPIC1021
THERMAL METRIC(1)
D (SOIC)
UNIT
8 PINS
RθJA
Junction-to-ambient thermal resistance
145
°C/W
RθJC(top)
Junction-to-case (top) thermal resistance
61.9
°C/W
RθJB
Junction-to-board thermal resistance
55.5
°C/W
ψJT
Junction-to-top characterization parameter
14.3
°C/W
ψJB
Junction-to-board characterization parameter
55
°C/W
(1)
4
For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application
report.
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7.5 Electrical Characteristics
VSUP = 7 V to 27 V, TA = –40°C to 125°C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP(1)
MAX
7
14
27
V
14
18
V
UNIT
SUPPLY
Operational supply voltage(2)
Nominal supply line
voltage(2)
7
VSUP undervoltage threshold(2)
4.5
Normal Mode, EN = 1, Bus dominant
(total bus load > 500 Ω)(3)
1.2
2.5
mA
1
2.1
mA
Normal Mode, EN = 1, Bus recessive
300
500
µA
Standby Mode, EN = 0, Bus recessive
Standby Mode, EN = 0, Bus dominant
(total bus load > 500 Ω)(3)
ICC
Supply Current
V
300
500
µA
Low Power Mode, EN = 0, VSUP < 14 V,
NWake = VSUP , LIN = VSUP
20
50
µA
Low Power Mode, EN = 0, 14 V < VSUP <
27 V, NWake = VSUP, LIN = VSUP
50
100
µA
RXD OUTPUT PIN
VO
Output voltage
IOL
Low-level output current, open drain LIN = 0 V, RXD = 0.4 V
-0.3
IIKG
Leakage current, high-level
LIN = VSUP, RXD = 5 V
5.5
3.5
-5
V
mA
0
5
µA
V
TXD INPUT PIN
VIL
Low-level input voltage(2)
-0.3
0.8
VIH
High-level input voltage(2)
2
5.5
V
VIT
Input threshold hysteresis voltage(2)
30
500
mV
Pull-down resistor
IIL
Low-level input current
TXD = 0
125
350
800
kΩ
-5
0
5
µA
LIN PIN (Referenced to VSUP)
VOH
High-level output voltage(2)
LIN recessive, TXD = High, IO = 0 mA
VOL
voltage(2)
LIN dominant, TXD = Low, IO = 40 mA
Low-level output
Pull-up resistor to VSUP
VSUP-1V
V
0.2×VSUP
V
20
0
30
60
kΩ
IL
Limiting current
TXD = Low
50
150
250
mA
IIKG
Leakage current
LIN = VSUP
-5
0
5
µA
VIL
Low-level input
voltage(2)
LIN dominant
0×VSUP
0.4×VSUP
V
VIH
High-level input voltage(2)
LIN recessive
0.6×VSUP
VSUP
V
VIT
Input threshold
voltage(2)
0.6×VSUP
V
Vhys
Hysteresis voltage(2)
0.175×VSUP
V
VIL
Low-level input voltage for wakeup(2)
0.4×VSUP
0.5×VSUP
0.05×VSUP
0
0.4×VSUP
V
EN PIN
VIL
Low-level input voltage(2)
VIH
High-level input
voltage(2)
Vhys
Hysteresis voltage(2)
-0.3
Pull-down resistor
IIL
Low-level input current
EN = 0 V
0.8
V
2
5.5
V
30
500
mV
125
350
800
kΩ
-5
0
5
µA
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7.5 Electrical Characteristics (continued)
VSUP = 7 V to 27 V, TA = –40°C to 125°C (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP(1)
MAX
UNIT
INH PIN
Vo
DC output voltage
IO
Output current
Transient voltage
-0.3
VSUP+0.3
-50
2
V
Ron
On state resistance
Between VSUP and INH, INH = 2 mA
drive, Normal or Standby Mode
25
40
100
Ω
IIKG
Leakage current
Low Power mode, 0 < INH < VSUP
-5
0
5
µA
mA
NWake PIN
VIL
Low-level input voltage(2)
-0.3
VSUP-3.3
V
VIH
High-level input voltage(2)
VSUP-1
VSUP+0.3
V
IIKG
Pull-up current
NWake = 0 V
Leakage current
VSUP = NWake
-40
-10
-4
µA
-5
0
5
µA
THERMAL SHUTDOWN
Shutdown junction thermal
temperature
(1)
(2)
(3)
185
°C
Typical values are given for VSUP = 14 V at 25°C.
All voltages are defined with respect to ground; positive currents flow into the TPIC1021 device.
In the dominant state the supply current increases as the supply voltage increases due to the integrated LIN responder termination
resistance. At higher voltages the majority of supply current is through the termination resistance. The minimum resistance of the
LIN responder termination is 20 kΩ so the maximum supply current attributed to the termination is: ISUP (dom) max termination ≈ (VSUP –
(VLIN_Dominant+0.7 V) / 20 kΩ.
7.6 Timing Requirements
MIN
MAX UNIT
D1
Duty cycle 1(1) (2)
D2
Duty cycle 2(1) (2)
THREC(max) = 0.284×VSUP, THDOM(max) = 0.422×VSUP, VSUP
= 7.6 V to 18 V, tBIT = 50 µs (20 kbps), See Figure 7-1
D3
Duty cycle 3(1) (2)
THREC(max) = 0.778×VSUP, THDOM(max) = 0.616×VSUP, VSUP
= 7.0 V to 18 V, tBIT = 96 µs (10.4 kbps), See Figure 7-1
D4
Duty cycle 4(1) (2)
THREC(max) = 0.251×VSUP, THDOM(max) = 0.389×VSUP, VSUP
= 7.6 V to 18 V, tBIT = 96 µs (10.4 kbps), See Figure 7-1
trx_pdr
Receiver rising propagation delay
time
RL = 2.4 kΩ, CL = 20 pF, See Figure 7-1
6
µs
trx_pdf
Receiver rising propagation delay
time
RL = 2.4 kΩ, CL = 20 pF, See Figure 7-1
6
µs
trx_sym
Symmetry of receiver propagation
delay time (rising edge)
with respect to falling edge, See Figure 7-1
2
µs
tNWake
NWake filter time for local wake-up See Figure 7-1
25
50
100
µs
tLINBUS
LIN wake-up filter time (dominant
time for wake-up via LIN bus)
See Figure 7-1
25
50
100
µs
tDST
Dominant state timeout(3)
See Figure 7-1
6
9
14
ms
(1)
(2)
(3)
6
NOM
THREC(max) = 0.744×VSUP, THDOM(max) = 0.581×VSUP, VSUP
= 7.0 V to 18 V, tBIT = 50 µs (20 kbps), See Figure 7-1
0.396
0.581
0.417
0.590
–2
Duty cycle = tBUS_rec(min)/ (2×tBIT)
Duty Cycles: LIN Driver bus load conditions (CLINBUS, RLINBUS): Load1 = 1 nF, 1 kΩ; Load2 = 6.8 nF, 660 Ω; Load3 = 10 nF, 500
Ω. Duty Cycles 3 and 4 are defined for 10.4 kbps operation. The TPIC1021 also meets these lower speed requirements, while it is
capable of the higher speed 20.0 kbps operation as specified by Duty Cycles 1 and 2. SAEJ2602 derives propagation delay equations
from the LIN 2.0 duty cycle definitions (LIN 2.1 compatible), for details please refer to the SAEJ2602 specification.
Dominant state timeout will limit the minimum data rate to 2.4 kbps.
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tBit
tBit
tBit
RECESSIVE
TXD (Input)
DOMINANT
tBus_dom(max)
tBus_rec(min)
THRec(max)
THDom(max)
Thresholds of
receiving node 1
VSUP
LIN Bus Signal
(Transceiver supply
of transmitting node)
Thresholds of
receiving node 2
THRec(min)
THDom(min)
tBus_dom(min)
tBus_rec(max)
RXD
(Output of receiving node 1)
trx_pdf(1)
trx_pdr(1)
RXD
(Output of receiving node 2)
trx_pdf(2)
trx_pdr(2)
Figure 7-1. Definition of Bus Timing Parameters
7.7 Typical Characteristics
0.7
20
18
0.6
16
0.5
14
VSUPPLY
VLIN
12
10
8
6
0.4
0.3
0.2
4
0.1
VLIN 25°C
VLIN 125°C
2
VLIN 25°C
VLIN 125°C
0
0
0
2
4
6
8
10
12
14
16
18
VSUPPLY
20
0
2
D001
Figure 7-2. VOH vs VSUPPLY and Temperature
4
6
8
10
VOL
12
14
16
18
20
D002
Figure 7-3. VOL vs VSUPPLY and Temperature
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8 Detailed Description
8.1 Overview
The TPIC1021 is a LIN (Local Interconnect Network) physical layer transceiver which integrates a serial
transceiver with wake up and protection features. The LIN bus is a single wire, bi-directional bus that typically is
used in low speed in vehicle networks with data rates that range from 2.4 kbps to 20 kbps.
8.2 Functional Block Diagram
8
7
1
RXD
Receiver
INH
VSUP
VSUP/2
2
EN
NWake
3
Wake−Up
and
Vreg Control
Filter
Filter
Dominant
State
Timeout
4
TXD
Fault
Detection and
Protection
6
LIN
5
Driver
GND
with Slope
Control
8.3 Feature Description
8.3.1 LIN Bus Pin
This I/O pin is the single-wire LIN bus transmitter and receiver.
8.3.1.1 Transmitter Characteristics
The driver is a low side transistor with internal current limitation and thermal shutdown. There is an internal
30-kΩ pull-up resistor with a serial diode structure to Vsup so no external pull-up components are required for
LIN responder mode applications. An external pull-up resistor of 1 kΩ plus a series diode to Vsup must be added
when the device is used for commander node applications.
Voltage on the LIN pin can go from -40 V to +40 V DC without any currents other than through the pull-up
resistance. There are no reverse currents from the LIN bus to supply (Vsup), even in the event of a ground shift
or loss of supply (Vsup).
The LIN thresholds and AC parameters are up-to-date with LIN Protocol Specification Revision 2.0, and
compatible with Revision 2.1.
During a thermal shut down condition the driver is disabled.
8.3.1.2 Receiver Characteristics
The characteristic thresholds of the receiver are ratio-metric with the device supply pin. Typical thresholds are
50%, with a hysteresis between 5% and 17.5% of supply.
8
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8.3.2 Transmit Input Pin (TXD)
This pin is the interface to the MCU’s LIN Protocol Controller or SCI/UART used to control the state of the LIN
output. When TXD is low, LIN output is dominant (near ground). When TXD is high, LIN output is recessive (near
battery). TXD input structure is compatible with microcontrollers with 3.3 V and 5.0 V I/O. This pin has an internal
pull-down resistor.
8.3.2.1 TXD Dominant State Timeout
If the TXD pin is inadvertently driven permanently low by a hardware or software application failure, the LIN bus
is protected by TPIC1021’s Dominant State Timeout Timer. This timer is triggered by a falling edge on the TXD
pin. If the low signal remains on the TXD pin for longer than tDST, the transmitter is disabled thus allowing the LIN
bus to return to the recessive state and communication to resume on the bus. The timer is reset by a rising edge
on TXD pin.
8.3.3 Receive Output Pin (RXD)
This pin is the interface to the LIN protocol controller or SCI/UART of the MCU, which reports the state of the LIN
bus voltage. LIN recessive (near battery) is represented by a high level on RXD and LIN dominant (near ground)
is represented by a low level on RXD. The RXD output structure is an open-drain output stage. This allows the
TPIC1021 to be used with 3.3 V and 5 V I/O microcontrollers. If the microcontroller’s RXD pin does not have an
integrated pull-up, an external pull-up resistor to the microcontroller I/O supply voltage is required.
8.3.3.1 RXD Wake-up Request
When the TPIC1021 has been in low power mode and encounters a wake-up event from the LIN bus or NWake
pin the RXD pin will go LOW while the device enters and remains in Standby Mode (until EN is re-asserted high
and the device enters Normal Mode).
8.3.4 Ground (GND)
This is the TPIC1021 device ground connection. The TPIC1021 operates with a ground shift as long as the
ground shift does not reduce VSUP below the minimum operating voltage. If there is a loss of ground at the ECU
level, the TPIC1021 does not have a significant current consumption on the LIN pin while in the recessive state
( VSUP_unde, EN = 0
C:VSUP > VSUP_unde, EN = 1
VSUP < VSUP_under
A
A
A
Standby
Mode
C
EN = 1
Normal Mode
TXD: on
RXD: LIN bus data
INH: HIGH (high
side switched on)
Term: 30 k
B
TXD: off
RXD: LOW
INH: HIGH (high
side switched on)
Term: 30 k
LIN Bus Wake−UP
or
NWake Pin Wake−Up
Low Power
Mode
TXD: off
RXD: floating
INH: high
impedance (high
side switched off)
Term: high
EN = 0
EN = 1
Figure 8-1. Operating States Diagram
Table 8-1. Operating Modes
MODE
EN
RXD
LIN BUS
TERMINATION
INH
TRANSMITTER
Low Power
0
Floating
High impedance
High impedance
Off
Standby
0
Low
30 kΩ (typical)
High
Off
Normal
1
LIN bus data
30 kΩ (typical)
High
On
COMMENTS
Wake-up event detected,
waiting on MCU to set EN
8.4.1.1 Normal Mode
This is the normal operational mode where the receiver and driver are active. The receiver detects the data
stream on the LIN bus and outputs it on the RXD pin for the LIN controller where recessive on the LIN bus is a
digital high and dominate on the LIN bus is digital low. The driver transmits input data on the TXD pin to the LIN
bus.
10
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8.4.1.2 Low Power Mode
The power saving mode for the TPIC1021 and the default state after power-up (assuming EN=0). Even with the
extremely low current consumption in this mode, the TPIC1021 can still wake-up from LIN bus activity, a falling
edge on the NWake pin or if EN is set high. The LIN bus and NWake pins are filtered to prevent false wake-up
events. The wake-up events must be active for their respective time periods: tLINBUS, tNWake.
The low power mode is entered by setting the EN pin low.
While the device is in low power mode the following conditions exist:
•
•
•
•
The LIN bus driver is disabled and the internal LIN bus termination is switched off (to minimize power loss if
LIN is short-circuited to ground).
The normal receiver is disabled.
The INH pin is high impedance.
EN input, NWake input and the LIN wake-up receiver are active.
8.4.1.3 Wake-Up Events
There are three ways to wake-up the TPIC1021 from Low Power Mode.
•
•
•
Remote wake-up via recessive (high) to dominant (low) state transition on LIN Bus where dominant bus state
of 50% threshold is detected. The dominant state must be held for tLINBUS filter time (to eliminate false wake
ups from disturbances on the LIN Bus).
Local wake-up via falling edge on NWake pin which is held low for filter time tNWake (to eliminate false wake
ups from disturbances on NWake).
Local wake-up via EN being set high
8.4.1.4 Standby Mode
This mode is entered whenever a wake-up event occurs via the LIN bus or NWake pin while the TPIC1021 is in
low power mode. The LIN bus responder termination circuit and the INH pin are turned on when standby mode
is entered. The application system powers up once the INH pin is driven high assuming it is using a voltage
regulator connected via INH pin. Standby Mode is signaled via a low level on RXD pin.
When EN pin is set high while the TPIC1021 is in Standby Mode the device returns to Normal Mode and the
normal transmission paths from TXD to LIN bus and LIN bus to RXD are turned on.
LIN
tLINBUS
VSUP
INH
High Impedance
EN
System Wake−Up Time (Vreg + MCU)
RXD
MODE
Floating
Low Power
Standby
Normal
Figure 8-2. Wake-Up Via LIN Bus Timing Diagram
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Falling Edge on NWake
NWake
tNWake
VSUP
INH
High Impedance
EN
System Wake−Up Time (Vreg + MCU)
RXD
MODE
Floating
Low Power
Standby
Normal
Figure 8-3. Wake-Up Via NWake Timing Diagram
8.4.2 Supply Voltage (VSUP)
This is the TPIC1021 device power supply pin. This pin is connected to the battery through an external reverse
battery blocking diode. The continuous DC operating voltage range for the TPIC1021 is from 7 V to +27 V. The
VSUP is protected for harsh automotive conditions of up to + 40 V.
The device contains a reset circuit to avoid false bus messages during undervoltage conditions when VSUP is
less than VSUP_UNDER.
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9 Application and Implementation
Note
Information in the following applications sections is not part of the TI component specification, and
TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining
suitability of components for their purposes. Customers should validate and test their design
implementation to confirm system functionality.
9.1 Application Information
The TPIC1021 can be used as both a responder device and a commander device in a LIN network. It comes
with the ability to support both remote wake-up requests and local wake-up requests.
9.2 Typical Application
The device comes with an integrated 30-kΩ pullup resistor and series diode for responder applications, and for
commander applications an external 1-kΩ pullup with series blocking diode can be used. Figure 9-1 shows the
device being used in both types of applications.
VBAT
VSUP
TPIC7xxxx
COMMANDER
NODE
VSUP
VDD
NWake
Commander
Node
Pull−Up 3
INH
VSUP
VDD
EN
MCU
TMS430
TMS470
GND
VSUP
2
8
MCU w/o
pull−up2
VDD I/O
LIN
Controller
or
SCI/UART1
bat
RXD
TXD
3
7
1 kW
TPIC1021
LIN
1
6
4
220 pF
5
TPIC7xxxx
LIN Bus
VDD
RESPONDER
NODE
VSUP
VDD
NWake
INH
VSUP
VDD
EN
2
8
3
7
MCU w/o
pull−up 2
VDD I/O
MCU
TMS430
TMS470
LIN
Controller
or
SCI/UART1
GND
A.
B.
C.
RXD
TXD
TPIC1021
LIN
1
4
6
5
220 pF
See 1 in the Section 9.2.1 section
See 2 in the Section 9.2.1 section
See 3 in the Section 9.2.1 section
Figure 9-1. Typical Application Schematic
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9.2.1 Design Requirements
For this design, use these requirements:
1. RXD on MCU or LIN Responder has internal pullup, no external pullup resistor is needed.
2. RXD on MCU or LIN Responder without internal pull-up, requires external pullup resistor.
3. Commander Node applications require an external 1-kΩ pullup resistor and serial diode.
9.2.2 Detailed Design Procedure
The RXD output structure is an open-drain output stage. This allows the TPIC1021 to be used with 3.3-V and
5-V I/O microcontrollers. If the RXD pin of the microcontroller does not have an integrated pull-up, an external
pullup resistor to the microcontroller I/O supply voltage is required.
The VSUP pin of the device should be decoupled with a 100-nF capacitor as close to the supply pin of the device
as possible.
The NWAKE pin is a high voltage wake-up input to the device. If this pin is not being used it should be tied to
VSUP.
9.2.3 Application Curves
Figure 9-2 and Figure 9-3 show the propagation delay from the TXD pin to the LIN pin for both the recessive to
dominant and dominant to recessive states under lightly loaded conditions.
Figure 9-2. Dominant to Recessive Propagation
Delay
Figure 9-3. Recessive to Dominant Propagation
Delay
9.3 Power Supply Recommendations
The TPIC1021 was designed to operate directly off car battery, or any other DC supply ranging from 7 V to 27 V.
A 100-nF decoupling capacitor should be placed as close to the VSUP pin of the device as possible.
9.4 Layout
9.4.1 Layout Guidelines
•
•
•
14
Pin 1 is the RXD output of the TPIC1021. It is an open drain output and requires an external pull-up resistor
in the range of 1 to 10 kΩ to function properly. If the micro-processor paired with the transceiver does not
have an integrated pullup and external resistor should be placed between RXD and the regulated voltage
supply for the micro-processor.
Pin 2 is the EN input pin for the device that is used to place the device in low power sleep mode. If this
feature is not used on the device, the pin should be pulled high to the regulated voltage supply of the
micro-processor through a series 1-kΩ to 10-kΩ series resistor. Additionally, a series resistor may be placed
on the pin to limit the current on the digital lines in the case of an overvoltage fault.
Pin 3 is a high-voltage local wake up input pin. The device is typically externally controlled by a normally open
switch tied between NWAKE and ground. When the momentary switch is pressed the NWAKE pin is pulled to
ground signaling a local wake-up event. A series resistor between VBATT and the switch, and NWAKE and
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•
•
•
•
•
SLIS113E – OCTOBER 2004 – REVISED MAY 2022
the switch should be placed to limit current. If the NWAKE local wake-up feature is not used, the pin can be
tied to VSUP through a 1-kΩ to 10-kΩ pullup resistor.
Pin 4 is the transmit input signal to the device. A series resistor can be placed to limit the input current to the
device in the case of an overvoltage on this pin. Also a capacitor to ground can be placed close to the input
pin of the device to filter noise.
Pin 5 is the ground connection of the device. This pin should be tied to a ground plane through a short trace
with the use of two vias to limit total return inductance.
Pin 6 is the LIN bus connection of the device. For responder applications a 220pF bus capacitor is
implemented. For commander applications an additional series resistor and blocking diode should be placed
between the LIN pin and the VSUP pin.
Pin 7 is the supply pin for the device. A 100-nF decoupling capacitor should be placed as close to the device
as possible.
Pin 8 is a high-voltage output pin that may be used to control the local power supplies. If this feature is not
used the pin may be left floating.
Note
All ground and power connections should be made as short as possible and use at least two vias
to minimize the total loop inductance.
9.4.2 Layout Example
VµC
R1
VSUP
R2
RXD
C
VµC
GND
U1
U1
R5
R4
R3
VSUP
D2
R4
EN
INH
J1
C9
R3
D1
Only needed for
Commander
Nodes
GND
D3
R2
C1
TXD
GND
GND
GND
GND
Figure 9-4. Layout Example
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10 Device and Documentation Support
10.1 Receiving Notification of Documentation Updates
To receive notification of documentation updates, navigate to the device product folder on ti.com. Click on
Subscribe to updates to register and receive a weekly digest of any product information that has changed. For
change details, review the revision history included in any revised document.
10.2 Support Resources
TI E2E™ support forums are an engineer's go-to source for fast, verified answers and design help — straight
from the experts. Search existing answers or ask your own question to get the quick design help you need.
Linked content is provided "AS IS" by the respective contributors. They do not constitute TI specifications and do
not necessarily reflect TI's views; see TI's Terms of Use.
10.3 Trademarks
TI E2E™ is a trademark of Texas Instruments.
All trademarks are the property of their respective owners.
10.4 Electrostatic Discharge Caution
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled
with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may
be more susceptible to damage because very small parametric changes could cause the device not to meet its published
specifications.
10.5 Glossary
TI Glossary
This glossary lists and explains terms, acronyms, and definitions.
11 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
16
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PACKAGE OPTION ADDENDUM
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10-Dec-2020
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
(4/5)
(6)
TPIC1021D
NRND
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
TPIC1021DG4
NRND
SOIC
D
8
75
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
TPIC1021DR
NRND
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
TPIC1021DRG4
NRND
SOIC
D
8
2500
RoHS & Green
NIPDAU
Level-1-260C-UNLIM
-40 to 125
T1021
T1021
-40 to 125
T1021
T1021
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of