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User's Guide

SLLU172 – August 2012

SN65HVD257 CAN EVM:

Functional Safety and Redundant CAN Network

This User Guide details the SN65HVD257 CAN EVM (Controller Area Network Evaluation Module)
transceiver operation. It comes with two SN65HVD257 CAN transceivers factory installed, set up in a
redundant (parallel) CAN bus configuration. The EVM may be reconfigured by a user for other CAN
topologies. This User’s Guide explains the EVM configurations for basic redundant CAN evaluation, and
includes various load and termination settings.

Contents

1

Introduction

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2

1.1

Overview

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2

1.2

Example Using the SN65HVD257 in a Redundant Physical Layer CAN Network Topology

............

2

2

SN65HVD257 CAN EVM

..................................................................................................

4

3

SN65HVD257 EVM Setup and Operation for Redundant (Parallel Networks)

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7

3.1

Overview and Basic Operation Settings

........................................................................

7

3.2

Using CAN Bus Load and Termination Configuration

.........................................................

9

3.3

Using CAN Bus Protection and Filtering Configuration

......................................................

10

3.4

Using Customer Installable IO Options for Current Limiting, Pull up or down, Noise Filtering

.........

11

3.5

Using customer installable IO options for 3.3V IO

...........................................................

11

4

SN65HVD257 EVM Configuration for Two Independent Networks

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12

4.1

Transceiver 1 Header (JMP3)

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12

4.2

Transceiver 2 Header (JMP7)

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12

5

Bill of Material (BOM)

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14

List of Figures

1

SN65HVD257 Basic Block Diagram and Pin Out

.......................................................................

2

2

Typical SN65HVD257 Node To Build A Redundant Physical Layer Topology

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3

3

Typical Redundant Physical Layer Topology Using SN65HVD257

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3

4

SN65HVD257 CAN EVM Top

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4

5

CAN EVM Schematic

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5

6

Loopback Node 1 (JMP5 to JMP12)

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13

7

Loopback Node 2 (JMP10 to JMP13)

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13

List of Tables

1

SN65HVD257 CAN EVM Connections

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6

2

Main Supply and IO Header (JMP1) Connections

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7

3

CAN Bus Termination Configuration

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9

4

CAN Bus Protection and Filtering Configuration

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10

5

EVM Digital IO Configuration

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11

6

EVM Digital IO Configuration

............................................................................................

11

1

SLLU172 – August 2012

SN65HVD257 CAN EVM: Functional Safety and Redundant CAN Network

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Copyright © 2012, Texas Instruments Incorporated

Содержание SN65HVD257

Страница 1: ...d Filtering Configuration 10 3 4 Using Customer Installable IO Options for Current Limiting Pull up or down Noise Filtering 11 3 5 Using customer installable IO options for 3 3V IO 11 4 SN65HVD257 EVM...

Страница 2: ...odes normal mode and silent mode selected on pin 8 The FAULT pin indicates TXD dominant time out RXD dominant time out thermal shut down and under voltage faults Figure 1 SN65HVD257 Basic Block Diagra...

Страница 3: ...combine the RXD outputs of both branches During dominant bits low were the branches do not match the XOR the circuit outputs a logic high A small RC filter on the output eliminates false outputs due t...

Страница 4: ...such as GND VCC TXD RXD CANH CANL S FAULT The EVM supports many options for CAN bus configuration It is pre configured with two 120 resistors that may be connected on the bus via jumpers a single resi...

Страница 5: ...5 GND 1 TP8 RXD 1 TP1 GND 1 C17 DNI U1 SN65HVD257 TXD 1 GND 2 Vcc 3 RXD 4 FLT 5 CANL 6 CANH 7 S 8 C13 1uF R10 DNI R17 0 U5 SN65HVD257 TXD 1 GND 2 Vcc 3 RXD 4 FLT 5 CANL 6 CANH 7 S 8 R19 330 C1 DNI TP7...

Страница 6: ...60 load for CAN transceiver parametric measurement JMP10 4 pin header Connection for access to transceiver 2 CAN bus output CANH2 CANL2 GND GND Connect 120 CAN termination to the bus Used in combinat...

Страница 7: ...XDprime RXD Receive Data 7 GND GND 8 VCC Pin 3 of Transceiver VCC 9 S2 Pin 5 of Transceiver 2 Used for Mode control 10 FLT2 Pin 8 of Transceiver 2 Indicates fault with transceiver 2 11 GND GND 12 FLT3...

Страница 8: ...MP1 and TP10 This output indicates a RXD DTO TXD DTO Thermal Shut Down or undervoltage fault with transceiver 1 3 1 7 FLT 2 FAULT pin 5 transceiver 2 JMP1 TP23 Pin 5 of transceiver 2 is the fault outp...

Страница 9: ...y the split capacitance is in the range of 4 7nF to 100nF Keep in mind that this is the common mode filter frequency not a differential filter that will impact the differential CAN signal directly Tab...

Страница 10: ...us filter environment Filter caps may be used in combination with L1 CM choke To add extra protection for system level transients and ESD protection use the D1 and D2 Transient Protection Transient ES...

Страница 11: ...ode pin input from JMP1 or PU or S U1 Input R1 JMP2 R2 NA C1 JMP2 PD to S U1 R27 S Mode pin input from JMP1 or PU or S U2 Input R25 JMP2 R26 NA C21 JMP2 PD to S U2 FAULT3 is the combined RXD output fr...

Страница 12: ...r 1 JMP3 may be used to route these signals to an external host processor or test system Make sure that the MODE JMP2 jumper settings are not conflicting with signals to JMP3 JMP2 transceiver 1 config...

Страница 13: ...nsceiver 2 Ensure JMP7 and JMP8 are not configured to conflict if TP19 is used as the input connection 4 2 4 FLT2 Output JMP7 TP23 Pin 5 of transceiver 2 is the fault output of the transceiver This ou...

Страница 14: ...2 JMP5 JMP10 Header 1x4 HDR_THVT_1X4_100 ANY ACT45B or B82789 series 17 2 L1 L2 DNI TDK EPCOS CM choke 18 4 R1 R16 R25 R40 4 7k 805 ANY R2 R3 R8 R15 R17 R20 R21 R26 19 11 0 805 ANY R27 R32 R39 20 4 R3...

Страница 15: ...o handling the product This notice contains important safety information about temperatures and voltages For additional information on TI s environmental and or safety programs please contact the TI a...

Страница 16: ...egulatory and safety related requirements concerning its products and any use of TI components in its applications notwithstanding any applications related information or support that may be provided...

Страница 17: ...Mouser Electronics Authorized Distributor Click to View Pricing Inventory Delivery Lifecycle Information Texas Instruments SN65HVD257EVM...

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