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EVM Setup and Operation

7

SLLU296 – August 2018

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Copyright © 2018, Texas Instruments Incorporated

TCAN1046V Evaluation Module

2.2

Using CAN Bus Load, Termination, and Protection Configurations

The TCAN1046V EVM has several bus termination options for both available buses. The termination on
the CAN bus (CANH and CANL) can be configured with the J2 and J3 (CAN1) or J6 and J8 (CAN2)
jumpers. Each jumper adds 120-

Ω

termination to the respective bus. When using one resistor, the EVM is

used as a terminated end of a bus. For electrical measurements to represent the total loading of the bus,
use both 120-

Ω

resistors in parallel to give the standard 60-

Ω

load for parametric measurement. Split

termination is also available and populated on both buses, and can be removed with some simple solder
work.

Table 3

summarizes how to use these termination options. If using split termination, match the

resistors. Calculate the common mode filter frequency using: f

C

= 1 / (2

π

RC). Normally, the split

capacitance is in the range of 4.7 nF to 100 nF. Keep in mind this is the common-mode filter frequency,
not a differential filter that impacts the differential CAN signal directly.

Table 3. Bus Termination Configuration

Termination

Configuration

120-

Ω

Resistors

(CAN1)

120-

Ω

Resistors

(CAN2)

Split Termination

Footprints

(CAN1)

Split Termination

Footprints

(CAN2)

Split

Terminati

on

Footprints

(CAN1)

Split

Terminati

on

Footprints

(CAN2)

J2

J3

J6

J8

R3

R7

R15

R21

C3

C12

Standard

termination (120

Ω

)

shorted

open

N/A

N/A

N/A

60-

Ω

load -

electrical

parameterics

shorted

shorted

Split termination

(common mode

stabilization)

open

open

60

Ω

60

Ω

populated

The EVM also has footprints for various protection schemes to enhance robustness for extreme system-
level EMC requirements.

Table 4

summarizes these options.

Table 4. Protection and Filtering Configuration

Configuration

Footprint Reference

Use Case

Population and Description

Series resistors or common

mode choke

R1/R9 or L1 (common

footprint)

Direct CAN1 transceiver to bus
connection

R1 and R9 populated with 0

Ω

Series resistance protection,
CAN1 transceiver to bus
connection

R1and R9 populated with MELF
resistor as necessary for harsh
EMC environment

CM choke (CAN1 bus filter)

L1 populated with CM choke to
filter noise as necessary for harsh
EMC environment (default
population)

R11/R25 or L2 (common

footprint)

Direct CAN2 transceiver to bus
connection

R11 and R25 populated with 0

Ω

Series resistance protection,
CAN2 transceiver to bus
connection

R11 and R25 populated with MELF
resistor as necessary for harsh
EMC environment

CM choke (CAN2 bus filter)

L1 populated with CM choke to
filter noise as necessary for harsh
EMC environment (default
population)

Bus filtering caps transient

protection

C1/C6

Bus filter

Filter noise as necessary for harsh
EMC environment. Use filter caps
in combination with L1 CM choke.

C9/C15

Filter noise as necessary for harsh
EMC environment. Use filter caps
in combination with L2 CM choke.

Summary of Contents for TCAN1046V

Page 1: ...TCAN1046V This user guide explains the EVM configurations for basic CAN evaluation and various load and termination settings Contents 1 Introduction 2 2 EVM Setup and Operation 5 3 CAN EVM Configurat...

Page 2: ...components as well as both CAN interfaces on the device separately 1 2 CAN EVM The TCAN1046V EVM has simple connections to all necessary pins of the CAN transceiver device and jumpers where necessary...

Page 3: ...P GND 0 1 F C8 DNP 0 1 F C10 DNP TP11 TP8 TXD1 1 GND 2 VCC 3 RXD1 4 GND 5 TXD2 6 RXD2 7 STB2 8 CANL2 9 CANH2 10 VIO 11 CANL1 12 CANH1 13 STB1 14 U1 TCAN1046VDRQ1 J4_STB1 CH1_L1 CL1_L1 CH2_B CL2_B CH1_...

Page 4: ...he CAN2 bus Use in combination with J3 to represent the combined 60 CAN termination J7 6 pin header Used to monitor CANH and CANL on CAN2 GND connections available as well J8 2 pin jumper Used to plac...

Page 5: ...2 J5 Pin Definitions Pin Connection Description 1 GND Pin 2 and 5 of the transceiver GND 2 VCC Pin 3 of the transceiver VCC 3 GND Pin 2 and 5 of the transceiver GND 4 VIO Pin 11 of the transceiver VIO...

Page 6: ...routed to JMP6 JMP2 and TP8 2 1 11 Pin 5 JMP6 Configurations 4 Way Jumper If using separate I O inputs JMP6 is used to configure pin 5 to pullup to VCC pulldown to GND VRXD or VIO supply input or VRE...

Page 7: ...Footprints CAN1 Split Terminati on Footprints CAN2 J2 J3 J6 J8 R3 R7 R15 R21 C3 C12 Standard termination 120 shorted open N A N A N A 60 load electrical parameterics shorted shorted Split termination...

Page 8: ...e EVM is being used as a CAN node Each digital input or output pin has footprints allowing for series current limiting resistors default populated with 0 pull up or down resistors depending on pin use...

Page 9: ...L2 GND2 VIO BIAS UNIT VCC 10 9 Low Power Standby Bus Receiver Monitor 6 8 DOMINANT TIME OUT VIO OVER TEMP DRIVER WAKE UP LOGIC MONITOR MUX LOGIC OUTPUT MODE AND CONTROL LOGIC 4 5 UNDER VOLTAGE VIO BIA...

Page 10: ...set forth above or credit User s account for such EVM TI s liability under this warranty shall be limited to EVMs that are returned during the warranty period to the address designated by TI and that...

Page 11: ...the antenna types listed in the user guide with the maximum permissible gain and required antenna impedance for each antenna type indicated Antenna types not included in this list having a gain great...

Page 12: ...t the EVM user guide prior to connecting any load to the EVM output If there is uncertainty as to the load specification please contact a TI field representative During normal operation even with the...

Page 13: ...OST OF REMOVAL OR REINSTALLATION ANCILLARY COSTS TO THE PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES RETESTING OUTSIDE COMPUTER TIME LABOR COSTS LOSS OF GOODWILL LOSS OF PROFITS LOSS OF SAVINGS LOSS OF...

Page 14: ...TI Resource NO OTHER LICENSE EXPRESS OR IMPLIED BY ESTOPPEL OR OTHERWISE TO ANY OTHER TI INTELLECTUAL PROPERTY RIGHT AND NO LICENSE TO ANY TECHNOLOGY OR INTELLECTUAL PROPERTY RIGHT OF TI OR ANY THIRD...

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