FlexRay Communications System Physical Layer Common mode Choke EMC Evaluation Specification Version 2.1
Disclaimer DISCLAIMER This specification as released by the FlexRay Consortium is intended for the purpose of information only. The use of material contained in this specification requires membership within the FlexRay Consortium or an agreement with the FlexRay Consortium. The FlexRay Consortium will not be liable for any unauthorized use of this Specification. Following the completion of the development of the FlexRay Communications System Specifications commercial exploitation licenses will be made available to End Users by way of an End User's License Agreement. Such licenses shall be contingent upon End Users granting reciprocal licenses to all Core Partners and non-assertions in favor of all Premium Associate Members, Associate Members and Development Members. All details and mechanisms concerning the bus guardian concept are defined in the FlexRay Bus Guardian Specifications. The FlexRay Communications System is currently specified for a baud rate of 10 Mbit/s. It may be extended to additional baud rates. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. The word FlexRay and the FlexRay logo are registered trademarks. Copyright 2004-2005 FlexRay Consortium. All rights reserved. The Core Partners of the FlexRay Consortium are BMW AG, DaimlerChrysler AG, Freescale GmbH, General Motors Corporation, Philips GmbH, Robert Bosch GmbH and Volkswagen AG. Version 2.1 December-2005 Page 2 of 19
Table of contents Table of contents CHAPTER 1 INTRODUCTION... 4 1.1 Scope... 4 1.2 References... 4 1.3 Terms and definitions... 5 1.4 List of abbreviations... 5 CHAPTER 2 REQUIRED TESTS... 6 2.1 Choke attenuation at DPI measurements... 6 2.1.1 Test conditions... 6 2.1.2 Test set-up... 8 2.1.3 Test procedure and parameters... 9 2.1.4 Test cases... 9 2.1.5 Limits-Results for reference type... 10 2.2 Choke attenuation at EMI measurements... 11 2.2.1 Test conditions... 11 2.2.2 Test set-up... 12 2.2.3 Test procedure and parameters... 13 2.2.4 Test cases... 13 2.2.5 Limits-Results for reference type... 13 2.3 Damage at ESD... 14 2.3.1 Test conditions... 14 2.3.2 Test set-up... 15 2.3.3 Test procedure and parameters... 16 2.3.4 Test cases... 16 2.3.5 Limits... 16 2.4 Influence of bus signals... 17 2.4.1 Test conditions... 17 2.4.2 Test set-up... 18 2.4.3 Test procedure and parameters... 19 2.4.4 Test cases... 19 2.4.5 Limits... 19 Version 2.1 December-2005 Page 3 of 19
Introduction Chapter 1 Introduction 1.1 Scope This test standard shall be used as a standardized common scale for evaluation of common mode chokes for FlexRay applications. All definitions of Physical Layer, EMC Measurement Specification, version 2.1 [9] are valid. This instruction includes limits, test procedures and test set-ups concerning: Choke attenuation at RF immunity measurements, Choke attenuation at RF emission measurements, Damage at ESD and Influence on bus signals. 1.2 References [1] FlexRay Communication System, Electrical Physical Layer Specification, Version 2.1 Revision A, December 2005 [2] IEC 61967-1, Integrated circuits, Measurement of electromagnetic emissions, 150 khz to 1 GHz Part 1: General and definitions. [3] IEC 61967-4, Integrated circuits, Measurement of electromagnetic emissions, 150 khz to 1 GHz Part 4: Measurement of conducted emissions 1 Ω/150 Ω direct coupling method [4] IEC 62132-1, Integrated circuits, Measurement of electromagnetic immunity, 150 khz to 1 GHz Part 1: General and definitions. [5] IEC 62132-4, Integrated circuits, Measurement of electromagnetic immunity, 150 khz to 1 GHz Part 4: Direct RF power injection method. [6] I ISO 7637-2, Road vehicles, electrical disturbances by conduction and coupling Part 2: Vehicles with nominal 12 V or 24 V supply voltage Electrical transients along supply lines only [7] ISO 7637-3, Road vehicles, electrical disturbances by conduction and coupling Part 3: Vehicles with nominal 12 V or 24 V Electrical transmission by capacitive and inductive coupling via lines other than supply lines [8] IEC 61000-4-2, Electromagnetic compatibility, Part 4-2: Testing and measurement techniques Electrostatic discharge immunity test. [9] FlexRay Communications System, Physical Layer, EMC Measurement Specification, version 2.1, December 2005 Version 2.1 December-2005 Page 4 of 19
Introduction 1.3 Terms and definitions FlexRay specific terms and definitions are listed in [1]. 1.4 List of abbreviations RF: DPI: CW: AM: radio frequency Direct Power Injection Continuous Wave Amplitude Modulation Version 2.1 December-2005 Page 5 of 19
Chapter 2 All tests shall be done in combination with one or two FlexRay Transceivers in node configuration. 2.1 Choke attenuation at DPI measurements 2.1.1 Test conditions For measuring the choke attenuation at DPI measurements on a FlexRay network, a minimum network of two bus nodes has to be set up according Figure 2-1. Version 2.1 December-2005 Page 6 of 19
JP11 STBN1 BGE1 EN1 R13 33k R53 R54 R55 R11)a 56/1k3 R12)a 56/1k3 Test choke L11 CM Choke R14 3k3 11 12 13 14 15 16 17 18 19 20 A1 TRXD0 RXEN ERRN WAKE BM BP VBUF TRXD1 STBN BGE RX TXEN TXD VIO EN INH1 INH2 10 9 8 7 6 5 4 3 2 1 R34 1K R35 1K X16 RX1 X17 TXEN1 X18 TX1 FlexRay TC C16)a 4.7n C11 C12 C13 C14 33µ R15 100k R16 100k C15 R100)a 56 Node 1 JP21 STBN2 BGE2 EN2 X7 RF1 C1 4,7n C2 4,7n R1 120 R2 120 Coupling bus lines R21)a 56/1k3 R22/a 56/1k3 Test choke L21 CM Choke R23 33k R24 3k3 11 12 13 14 15 16 17 18 19 20 A2 TRXD0 RXEN ERRN WAKE BM BP VBUF TRXD1 STBN BGE RX TXEN TXD VIO EN INH1 INH2 10 9 8 7 6 5 4 3 2 1 R58 R59 R60 R41 1K R42 1K X23 RX2 X24 TXEN2 X25 TX2 FlexRay TC C26)a 4.7n C21 C22 C23 C24 33µ R25 100k R26 100k C25 Node 2 a) placement and value depend on test case D2 L1 L2 JP1 L3 L4 e.g. BYD17K 47 µh C41 C42 330 p 1 n e.g. WE 742 750 4 47 µh e.g. WE 742 750 4 C44 C45 C43 1 n 330 p 22uF C46 22uF X28 VBat X29 X30 Filter Figure 2-1: Test circuit diagram for DPI measurements FlexRay nodes and filter description: See FlexRay Transceiver test specification [9]. Coupling of disturbances: The coupling of disturbances shall be realized by passive components. The maximum components tolerance is 1 %. For components used for symmetrical coupling (in pairs), a maximum tolerance of 0,1 % is demanded, which can be confirmed by measurement. Version 2.1 December-2005 Page 7 of 19
2.1.2 Test set-up The effect of the common mode choke for increasing the RF immunity of a FlexRay speed node shall be carried out by Direct Power Injection (DPI Test method) according to IEC 62132-4 and FlexRay paper EMC evaluation of FlexRay Transceivers. A general test set-up is illustrated in Figure 2-2. For test level definition the forward RF power shall be used. RF-Generation Power meter RF Generator Control PC Monitoring and Stimulation RF Amplifier IEC Bus IEC Bus DSO Pattern Gen. Power transition head RF PCB connector 1 TxD, TXEN RF1 2 RxD V BAT, V CC, 3 RF PCB connector External Power supply Test board Figure 2-2: Test set-up for DPI measurements Test equipment requirements: RF- Generator RF- Amplifier Power meter with directional coupler Test board DSO Pattern generator External power supply PC f = 1-1000 MHz, AM P CW 10 W f = 1-1000 MHz bandwidth 500 MHz Version 2.1 December-2005 Page 8 of 19
2.1.3 Test procedure and parameters The tests are based on the definitions of [9] for the DPI measurement with the following changes and extensions: Parameters Modulation AM 80 %, 1 khz ) 1 ) 1 control the power as CW value and apply the modulation afterwards Transceiver type Transceiver mode TJA1080N1D Normal, Stand By Failure validation Pin RxD 4 ns, according to FlexRay TC paper [9] Table 2-1: Test parameters for DPI measurements 2.1.4 Test cases The tests shall be performed and documented according the following scheme: Test Transceiver mode Type of coupling Coupling resistors Central bus termination Termination network R 1 R 2 R 100 R x1,2 C ground [nf] 1 Symmetric RF on Bus 120 120 56 1k3 not used Normal 2 not used 56 4,7 3 (with communication 10 % unsymmetrical RF 132 108 56 1k3 not used signal) on Bus 4 not used 56 4,7 5 Symmetric RF on Bus 120 120 56 1k3 not used Stand By 6 not used 56 4,7 7 (without communication 10 % unsymmetrical RF 132 108 56 1k3 not used signal) on Bus 8 not used 56 4,7 Table 2-2: Required DPI measurements For each measurement an immunity threshold curve with the forward power as the parameter has to be carried out and presented in the test report in a diagram. Version 2.1 December-2005 Page 9 of 19
2.1.5 Limits-Results for reference type Common Mode Chokes for FlexRay applications DPI- Measurement - Reference choke - [dbm] 40 [dbm] 35 RF- Coupling: Bus, symmetric Modulation: AM 80% 1kHz, CW contr. Failure validation: normal mode with TX, RX Common Mode Chokes for FlexRay applications DPI- Measurement - Reference choke - [dbm] 40 [dbm] 35 RF- Coupling: Bus, unsymmetric Modulation: AM 80% 1kHz, CW contr. Failure validation: normal mode with TX, RX 30 30 Limit 25 Limit Test case 1 25 Test case 3 Test case 4 20 Test case 2 20 15 15 10 1 10 100 1000 10 1 10 100 1000 Common Mode Chokes for FlexRay applications DPI- Measurement - Reference choke - [dbm] 40 [dbm] 35 RF- Coupling: Bus, symmetric Modulation: AM 80% 1kHz, CW contr. Failure validation: Stand by mode Common Mode Chokes for FlexRay applications DPI- Measurement - Reference choke - [dbm] 40 [dbm] 35 RF- Coupling: Bus, unsymmetric Modulation: AM 80% 1kHz, CW contr. Failure validation: Stand by mode 30 30 25 20 Limit Test case 5 Test case 6 25 20 Limit Test case 7 Test case 8 15 15 10 1 10 100 1000 10 1 10 100 1000 Figure 2-3: Test results for reference type, DPI measurement Version 2.1 December-2005 Page 10 of 19
2.2 Choke attenuation at EMI measurements 2.2.1 Test conditions For measuring the choke attenuation at EMI measurements on FlexRay transceivers a network with a transceiver, the common mode choke under test and a bus load circuit is used. RF decoupling a) placement and value depend on test case JP11 R13 33k STBN1BGE1 EN1 R53 R54 R55 X1 EMI1 C1 4,7n C2 4,7n R13 50 R1 120 R2 120 R100)a 110/56 R11)a 56/1k3 R12)a 56/1k3 Test choke L11 CM Choke C16)a 4.7n C11 R14 3k3 C12 11 12 13 14 15 16 17 18 19 20 C13 A1 TRXD0 RXEN ERRN WAKE BM BP VBUF TRXD1 STBN BGE RX TXEN TXD VIO EN INH1 INH2 FlexRay TC C14 33µ 10 9 8 7 6 5 4 3 2 1 R15 100k R16 100k C15 R34 1K R35 1K X16 RX1 X17 TXEN1 X18 TX1 Node 1 D2 L1 L2 JP1 L3 L4 e.g. BYD17K 47 µh C41 C42 330 p 1 n e.g. WE 742 750 4 47 µh e.g. WE 742 750 4 C44 C45 C43 1 n 330 p 22uF C46 22uF X28 VBat X29 X30 Filter Figure 2-4: Test circuit diagram for EMI measurements Version 2.1 December-2005 Page 11 of 19
2.2.2 Test set-up The effect of the common mode choke for decreasing the RF emission of a FlexRay node in the frequency domain shall be carried out according to IEC 61967-4 and FlexRay paper EMC evaluation of FlexRay Transceivers [9]. A general test set-up is illustrated in Figure 2-5. RF Analyzer Control PC Monitoring and Stimulation SA IEC Bus IEC Bus DSO Pattern Gen. RF PCB connector Decoupling bus line TxD, TXEN Bus load EMI1 TC RxD External Power supply V BAT, V CC, Test board RF PCB connector Figure 2-5: Test set-up for measurement of RF disturbances on the bus line Test equipment requirements: Spectrum analyzer / Measuring receiver according to CISPR 16 DSO with probes ( 1MΩ) bandwidth 500 MHz Test board Pattern generator External power supply PC Version 2.1 December-2005 Page 12 of 19
2.2.3 Test procedure and parameters The tests are based on the definitions of [9] for the 150 Ω- measurement method with the following extensions: Parameters Transceiver type TJA1080N1D Table 2-3: Parameters for emission test 2.2.4 Test cases The tests shall be performed and documented according the following scheme: Test Transceiver mode Type of decoupling Decoupling resistors Central bus termination Termination network R 1 R 2 R 100 R x1,2 C ground [nf] 1 56 1k3 not used Normal Symmetric of Bus 120 120 2 110 56 4,7 Table 2-4: Required EMI measurements 2.2.5 Limits-Results for reference type Common Mode Chokes for FlexRay applications EMI - Measurement - Reference choke - [dbµv] 70 Test case 1 Test case 2 60 50 40 30 20 10 0-10 0,1 1 10 100 [MHz] 1000 Figure 2-6: Test results for reference type, EMI measurement Version 2.1 December-2005 Page 13 of 19
2.3 Damage at ESD 2.3.1 Test conditions DP1 DP2 L1 CM Choke Test choke R1 30 R2 15 Figure 2-7: Test circuit diagram for ESD measurements All resistors shall be of the SMD design 1206 or 0805 with a maximum tolerance of 1%. The exact type ID and manufacturer of the used capacitors and resistors are to be documented in the test report. Coupling of the disturbances: The ESD coupling shall be implemented in a direct galvanic way by using a Contact Discharge Module according IEC 61000-4-2 (C = 150 pf, R = 330 Ω). For this purpose, the discharge points DP 1 and 2, carried out as rounded vias in the layout of the ESD test board, are directly connected by a trace (15 (-0 +5) mm) with the respective pin of the Transceiver. Version 2.1 December-2005 Page 14 of 19
2.3.2 Test set-up For testing the immunity of the common mode choke against damage caused by ESD measurements according to IEC 61000-4-2 shall be done. The test set-up is shown in Figure 2-8. ESD Simulator Common mode choke Load resistors Ground plane ESD Test board Test generator with contact discharge module connection loads to Ground plane ESD Test board R1 ESD Test board fixture Ground reverse line Test generator Discharge pads R2 Surface connection ESD Test board to Test board support ESD Test board Surface connection Test board fixture to ground plane Connection point Ground plane Ground plane (minimal 0,5 x 0,5 m) Figure 2-8: Test set-up for ESD- measurements The ground plane with a minimum size of 0,5 x 0,5 m builds the reference ground plane for the ESD Test set-up and must be connected with the electrical grounding system of test laboratory. The ESD Test generator ground cable shall be connected to this reference plane. The test board fixture realizes the positioning of the ESD Test board and the electrical connection of the ESD Test board ground plane with the reference ground plane. This connection must have low impedance (R < 25 mω) and should be built by a surface contact. On testing the tip of the ESD Test generator discharge module shall be directly contacted with one of the discharge pads EP1 to 2 of the ESD Test board. Test Equipment Requirements: ESD Test generator according IEC 61000-4-2; Contact discharge module (IEC- Relays) with Discharge capacitor 150 pf and Discharge Resistor 330 Ω ESD Test board Version 2.1 December-2005 Page 15 of 19
2.3.3 Test procedure and parameters The tests are based on the definitions of [9] with the following extensions: Parameters ESD test voltage Number of discharges Time between discharges Damage criteria ± 8 kv, ± 15 kv 10 per polarity 5 s maximum deviation of 5 % of parameters after the test to the starting values before: - Series resistance of line 1 and 2: R S1, R S2 ) 1 - Isolation resistance line 1 to line 2: R ISO ) 1 - Inductivity line 1 and 2: L S1, L S2 ) 2 ) 1 Measurement at +100 V DC test voltage for 2 s ) 2 Measurement at f = 1 MHz Table 2-5: Specifications for ESD measurements 2.3.4 Test cases The tests shall be performed and documented according the following scheme: Test Discharge points Comment 1 DP 1 Line 1 2 DP 2 Line 2 Table 2-6: Required ESD measurements 2.3.5 Limits The common mode choke must withstand the ESD discharge without damage on use oft the damage criteria. Version 2.1 December-2005 Page 16 of 19
2.4 Influence of bus signals 2.4.1 Test conditions For measuring the influence of the common mode choke to the bus signals at the defined test point TP2 (see [2]) a network with a transceiver, the test common mode choke and a bus load circuit is used. a) placement and value depend on test case STBN1BGE1 EN1 R53 R54 R55 C1 100p R100)a 110/56 BM TP2 R11)a 56/1k3 R12)a 56/1k3 Test choke L11 CM Choke BM TP1 BP TP1 11 12 13 14 15 16 17 18 19 20 A1 TRXD0 RXEN ERRN WAKE BM BP VBUF TRXD1 STBN BGE RX TXEN TXD VIO EN INH1 INH2 10 9 8 7 6 5 4 3 2 1 R34 1K R35 1K X16 RX1 X17 TXEN1 X18 TX1 FlexRay TC BP TP2 C16)a 4.7n C11 C12 C13 C14 33µ R15 100k R16 100k C15 Bus load Node 1 D2 L1 L2 JP1 L3 L4 e.g. BYD17K 47 µh C41 C42 330 p 1 n e.g. WE 742 750 4 47 µh e.g. WE 742 750 4 C44 C45 C43 1 n 330 p 22uF C46 22uF X28 VBat X29 X30 Filter Figure 2-9: Test circuit diagram for measuring of influence of bus signals at a FlexRay transceiver Version 2.1 December-2005 Page 17 of 19
2.4.2 Test set-up The influence of the common mode choke to the bus signals of a FlexRay node shall be carried out in the time domain according to the test set-up illustrated in Figure 2-10. Measurement and Stimulation DSO Pattern Gen. High impedant Voltage probes BP BM RxD TxD, TXEN RF PCB connector Bus load Choke TC TP1 + TP2 External power supply V BAT, V CC, Test board Figure 2-10: Test set-up for measurements of influence of bus signals Both voltage probes must be adapted at the same time to avoid unsymmetrical load conditions. Test equipment requirements: DSO High impedant voltage probe Test board Pattern generator External power supply bandwidth 500 MHz bandwidth 500 MHz Version 2.1 December-2005 Page 18 of 19
2.4.3 Test procedure and parameters The oscilloscope measurement shall be done with the following test values: Parameters Presentation of results differential bus signal: - Transmit eye-diagram at TP1 ([1], figure 7-2) and - Transmit eye-diagram at TP2 ([1], figure 7-4) Transceiver type Transceiver mode TJA1080N1D Normal TXD- Signal, TXEN- Signal see [9] Table 2-7: Parameters for oscilloscope measurement 2.4.4 Test cases The tests shall be performed and documented according the following scheme: Test Transceiver mode Central bus termination Termination network R 100 R x1,2 C ground [nf] 1 56 1k3 not used Normal 2 110 56 4,7 Table 2-8: Required EMI measurements 2.4.5 Limits The differential bus signal with common mode choke must be fulfill: Transmit eye-diagram at TP1 ([1], figure 7-2) and Transmit eye-diagram at TP2 ([1], figure 7-4) === END OF DOCUMENT === Version 2.1 December-2005 Page 19 of 19