October 2016 DocID029647 Rev 2 1/17

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UM2103 User manual

Getting started with STEVAL-OET003V1 evaluation board for automotive-grade ESD protection

Introduction The STEVAL-OET003V1 evaluation board is designed to provide a demonstration tool to evaluate ESD protection robustness for automotive applications.

The demonstration tool includes:

1. two STM8AF528 MCUs (one configured as the master node and the other as the slave node) 2. two NXP LIN bus transceivers 3. two NXP CAN bus transceivers 4. a step-up converter to boost 5 to 12 V for transceiver supply voltage 5. a linear regulator to obtain a 3.3 V supply voltage 6. an automotive-grade ESD protection device for each transceiver 7. possibility to test several ESD protection part numbers

The protection robustness is evaluated by monitoring the communication flow between the master and the slave nodes.

Figure 1: STEVAL-OET003V1 evaluation board

Contents UM2103

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Contents

1 Getting started ................................................................................ 4

2 Board description ........................................................................... 5

2.1 Board supply .................................................................................... 5

2.2 LIN and CAN connectors ................................................................. 5

3 Firmware description ..................................................................... 6

4 Block diagram ................................................................................. 7

5 ESD test .......................................................................................... 8

5.1 Connections (supply and data lines) ................................................ 8

5.2 ESD application ................................................................................ 8

5.3 ESD part number changes ............................................................... 9

6 Schematic diagrams ..................................................................... 10

7 Layout ........................................................................................... 13

8 Revision history ........................................................................... 16

UM2103 List of figures

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List of figures

Figure 1: STEVAL-OET003V1 evaluation board ........................................................................................ 1 Figure 2: STEVAL-OET003V1 block diagram ............................................................................................ 7 Figure 3: Contact ESD discharge ............................................................................................................... 8 Figure 4: Air ESD discharge ....................................................................................................................... 9 Figure 5: Power section ............................................................................................................................ 10 Figure 6: LIN section ................................................................................................................................. 10 Figure 7: CAN section ............................................................................................................................... 11 Figure 8: Master node ............................................................................................................................... 11 Figure 9: Slave node ................................................................................................................................. 12 Figure 10: STEVAL-OET003V1 top layer ................................................................................................. 13 Figure 11: STEVAL-OET003V1 bottom layer ........................................................................................... 14 Figure 12: STEVAL-OET003V1 silk screen top layer ............................................................................... 15

Getting started UM2103

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1 Getting started

To start the application board, connect the 5 V supply voltage to the screw connector and push the reset button to align the nodes.

The three-color LED (orange, yellow and blue) starts blinking sequentially to indicate normal communication; if a communication fault occurs, the blinking LED switches off and the red LED turns on.

UM2103 Board description

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2 Board description

The evaluation board implements a master/slave structure, by using two on-board STM8AF528 MCU nodes which communicate via a LIN/CAN protocol implementation.

The board features:

5 V input voltage

12 V output, boost topology converter for transceiver supply voltage

3.3 V regulated voltage

LIN bus transceiver

CAN bus transceiver

automotive grade ESD protections

IEC61000-4-2 & ISO10605 compatibility

The board is specifically designed to reduce noise impact due to electrostatic discharge. Refer to Section 7: "Layout" to view the ground track and plane design.

Regarding the ground net, a star connection links all the tracks to the A7985A ground reference pin; whereas, the ground plane is split in two parts: one for the master and one for the slave node, both referring to the respective ground connection.

2.1 Board supply

The board supplies three different voltage references: the microcontroller section, the LIN/CAN transceiver modules and the CAN connector.

The main voltage reference (Vin = 5 V) is provided through the J5 screw connector and the A7985A DC - DC converter (in boost topology) raises it to 12 V to obtain the supply voltage for the LIN and CAN transceivers.

Moreover, a 3.3 V reference (not available by default) is generated by using the ST LF33CDT-TRY very low drop voltage regulator, starting from 5 V input voltage (this reference is shown on the CAN connector); to enable this reference voltage, the J6 jumper must be closed and the C19 and C20 capacitors must be assembled.

2.2 LIN and CAN connectors

The CAN connection uses two standard RS232 connectors; while LIN communication uses two screw connectors (where it is possible to connect an external supply voltage for the transceiver module and the LIN bus).

Firmware description UM2103

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3 Firmware description

The communication described is mainly based on a simple LIN/CAN communication, where the loop status (normal or fault) is shown respectively by:

a three-color LED (orange, blue or purple in case of normal operation)

a red LED if the communication fails

The communication flow starts when the master sends the LIN frame to the slave.

If the received frame is correctly recognized, the slave sends a new frame to the master through the CAN protocol; after frame reception, the status loop is incremented by switching a new LED on.

If the communication is corrupted, the status LED turns off and the red LED switches on.

UM2103 Block diagram

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4 Block diagram Figure 2: STEVAL-OET003V1 block diagram

ESD test UM2103

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5 ESD test

5.1 Connections (supply and data lines)

Supply: 5 V must be connected to the J5 screw connector.

CAN connection: through DB9 female connectors, connect one wire between pins 2 (CANL) to standard RS232 connector (DB9 male P1 and P2) and one other wire between pins 7 (CANH) standard RS232 connector (DB9 male P1 and P2).

LIN: 1 wire between pin 1 of J12 and pin 3 of J9 screw connectors.

When the board is supplied and data lines connected, the green and red LEDs will turn on. Push the “SW1” button and then, 3 LEDs will blink (the red LED turns off).

The evaluation board is now ready for the ESD test.

5.2 ESD application

Figure 3: Contact ESD discharge

ESD contact: the ground ESD gun can be applied directly to the PCB ground with the GND plane close to the P1 connector. The ESD gun tip is applied on nail LIN (ESD_TIP6 & 7 markings) or nail CAN (ESD_TIP1 to 4 markings) and then ESD shoots can be performed.

UM2103 ESD test

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If the LEDs stop blinking, push the “SW2” button and then the “SW1” button. The demo board is still operational and the LEDs blink again.

Figure 4: Air ESD discharge

ESD air: the same connections must be done, but the ESD gun tip placed close to DB9 and the screw connectors where the data line wires are connected.

By default, ESDCAN02-2BWY and ESDLIN1524BJ are soldered on the PCB to protect the transceivers against ESD discharge.

For each ESD protection device (see the next section to test other ESD protection devices), the evaluation board is always operational even for ESD levels equal to ± 30 kV in contact or air ESD discharge, and this is for R = 330 Ω and C = 330 pF or other RC values and for more than 3 pulses (ISO10605 conditions).

5.3 ESD part number changes

It is possible to change ESD protection devices. The first step is to unsolder (with air heater, for example) ESDLINxx (D14(15)) or D17(18)), or ESDCANxx (D1(2) or D7(8)) close to the connectors. ESDLINxx and ESDCANxx samples are available in a bag (see list below). ESDCAN footprints are compatible with all ESDCANxx part numbers and for LIN part. ESD tests can be performed again after ESD device replacement.

ESD protection available in STEVAL-OET003:

ESDCAN02-2BWY in SOT323-3L (Marking: C02) (2 samples soldered on PCB)

ESDLIN1524BJ in SOD323 (Marking: 24) (2 samples soldered on PCB)

Part numbers available in bag:

ESDCAN03-2BWY in SOT323-3L (Marking: C03) (1 sample)

ESDCAN01-2BLY in SOT23-3L (Marking: EN24) (1 sample)

ESDCAN24-2BLY in SOT23-3L (Marking: EL24) (1 sample)

ESDLIN03-1BWY in SOT323-3L (Marking: C12) (1 sample)

Schematic diagrams UM2103

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6 Schematic diagrams Figure 5: Power section

Figure 6: LIN section

1

R21

1.5k

C22n2, 25V

U16

ESDA14V2SC5Y

C9470pF

6

1

Vcc

9

3

1

D6

STPS3L40-Y

3

R111K

2

7

2

Fsw

C6

100nF

2

4 1

EN

STEP UP CONVERTER 5V to 12V

2

2

R222.49k, 1%

R1947k, 1%

1

1

2

Q1STN4NF06L

D5STPS3L40-Y

L222uH

8

5

1

4COMP

+5V

TP

2

2

1

3FB

2

1

C10100nF

1

2

2

GND

Vout

1

2

R20220R

1

1

2

SY

C82n2, 25V

2

4

1

2

R18110k

2

+12V

1

U2

A7985A

2

1

5

1

C5

10uF

6

1

2

B1

CG2

C17N.M

C202.2u N.M.

J5

DC-10B

D11SM4T6V7AY

1VIN

3PSG

C15100nF

3V3

1

POWER INPUT AND PROTECTION

5Vin

5

GN

D

1

1

1

1

1

1

2

6CG3

2

U7LF33CDT-TRY N.M.

2

2

2

2

3VOUT

1

0

U6

Murata BNX002-01

2

2

CG1

1

2

2 1CB

J65Vto3V3

C18N.M.

2

2

R39PTC 0.12 1/8W

+5V

C1610uF

C19100nF N.M.

4

LINCAN MCUPOWER

D15

22

1

+12V

1

BAT48ZFILMD16

TP14

UART3_TX

2

BAT48ZFILM

GND

1

1

1

2

UART1_RX INH

2

1

2

D18

1

6

1

LIN

2

J12LIN OUTPUT

1

FOR VOLTAGE PROBE

HIGH CURRENT 50A for 1nSec

TXD

2

R404K7

LIN_EN_MCU2

4

TP13

2

WUP3

LIN

2

1

1

R49N.M

1

C25100nF

INH8

2

TP20

ESD_Tip7

R52N.M.10k

U8

1

1

D13

LIN

C26100nF

RXD

1

2

1RXD

8

D17

ESDLIN1524

J11

JUMPER1

3

Vs

WUP

1

TP18

TP21

2

1

1

2

1R480

VBAT

1

NORMAL OPEN

7

6

3

VBAT

2

J10

JUMPER

1

C22100nF

2

2

U10

TP19

TP17

1

2

J8

JUMPER1

R410

MASTER

12V VCC

LIN

GND

UART3_RX

+12V

UART1_TX

1

R5010k

2

1

U9

TJA1021T/10

C27220pF

1

SLAVE

SLP_N

ESD PROTECTION LIN

1

J9LIN OUTPUT

7

12V VCC

LIN

GND

D14

ESDLIN1524

1

1

R4510k

1

2

R510R

2

2

TP16

Vs

1

TP15

2

2

FOR VOLTAGE PROBE

HIGH CURRENT 50A for 1nSec

2

R440R

5

SLP_N

2

R474K7

1

C231nF

U11

TJA1021T/10

2

C21

100nF

1

1

2

2

2

2

ESD PROTECTION LIN

SOD323 SOD523

D12BAT48ZFILM

C24

100nF

1

GND5

SOD323 SOD523

1

LIN_EN_MCU1

TXD

R46N.M.10k

R43

1K

1

1

NORMAL OPEN

J7

JUMPER

2

2

1

ESD_Tip6

4

3

UM2103 Schematic diagrams

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Figure 7: CAN section

Figure 8: Master node

11

2

R26N.M.

6

U5

R23N.M.

2

J2

JUMPER1

M1

GND

1

CAN TX_MCU2

+12V

3V3

J1JUMPER

Vbat

SPLIT

CANH

CANL

CANH

CANL

GND

1

1

R340R

C747pF

1

R4N.M.

EN

1 BAT48ZFILM

CAN RX_MCU1

1

ESD_Tip1

7

1

2

2

1

1

2

CA

N C

ON

NE

CT

OR

BAT48ZFILM10

2

J4JUMPER

2

2

4

TP9

8

RXD

3

2

C1100nF

9

1

3V3

ERR_N

12

8

1

C1347pF

ESD PROTECTION CAN

2

2

2

ESD_Tip4TP7

1

R38N.M.10k

WAKE

1

3

2

2

2

2

INH

1

1

1

1

R15N.M.

TXD

R27N.M.

TP8

1

R36N.M.

2

EN CAN_MCU2

VBATCANL 2

STB_N

ESD PROTECTION CAN

9

SPLIT

P2

M2

1

1

2

4RXD

R140R

R10

N.M.

C1447pF

2

1

1

C347pF

C12100nF

2

2

TP2

8

2

L3

CHOKE CM

Vbat

7

12

2

R90R

2

NORMAL CLOSED

1

2

VIO

VCC

2

1

6

4

TP1

1

CANL

D2

ESDCAN24

L1

CHOKE CM

NORMAL CLOSED

CA

N C

ON

NE

CT

OR

1

1

1

1 1

2

R25N.M.

6

2

4

ESD_Tip3

R300R

D10

1

2

5

VCC

R35N.M.

1

U1

TJA1043T

2

R13120R

1

STB_NR240R

GND

1

R320R

13CANH

CANH

CANL

4

14

+5V

EN CAN_MCU1

M1

D1ESDCAN24

1

11

VIO

SPLIT

10

1

R10R

3

VBAT

1

TP10

R1710k

R8N.M.

1

4

TP4 1

R33120R

J3

JUMPER1

1

9WAKE

TXD

2

2

D7

ESDCAN24

3

1

ERR_N

1

7

2

M2

2

1

C447pF

INH

R31

N.M.

3

CAN TX_MCU1

Common Mode ChokeACT45B-101-2PTDK

2

R29N.M.

SPLIT

CANH

CANL

D8

ESDCAN24

U3ERR_N CAN_MCU1

5

P1

R3710k

R2N.M.

CAN RX_MCU2S

TB

_N

CA

N_

MC

U2

6

D4

ESD_Tip2

2

3

2

EN

TP5

R5N.M.

5

1

R3N.M.10k

5

2

13CANH

R120R

ERR_N CAN_MCU2

9

CANH

CANL

CANH

CANL

GND

1

8

2

CAN

R6N.M.

MASTER

SLAVE

7

14

Common Mode ChokeACT45B-101-2PTDK

R16N.M.

2

R7N.M.

1

+12V

ST

B_

N C

AN

_M

CU

1

C1147pF

R28N.M.

1

1 U4

TJA1043T

2

1

1

Schematic diagrams UM2103

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Figure 9: Slave node

UM2103 Layout

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7 Layout Figure 10: STEVAL-OET003V1 top layer

Layout UM2103

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Figure 11: STEVAL-OET003V1 bottom layer

UM2103 Layout

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Figure 12: STEVAL-OET003V1 silk screen top layer

Revision history UM2103

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8 Revision history Table 1: Document revision history

Date Revision Changes

26-Aug-2016 1 Initial release.

24-Oct-2016 2 Added Section 5: "ESD test"

Minor text corrections throughout document

UM2103

DocID029647 Rev 2 17/17

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