1. CAN Specifications Issues: –Width required for FPC CAN tracks –Number of twists per unit length in automotive CAN wires

2. ISO 11898 CAN standard Table 13: Physical Media Parameters

3. CAN Track Width ISO 11898 length related resistance: 70 m /m Easy to achieve with wire (0.26mm 2 ) Do we need to meet this standard on FPC? Implied track width 7.6 mm (for 1oz copper)

4. CAN Track Width Consultation: –CAN group Warwick University –STA Reutlingen, Germany We do not need to meet 70 m /m 2mm or even 1 mm width tracks OK EMC test patterns mostly use 2mm

5. Twists Per Unit Length NOT specified in ISO11898 standard STA Reutlingen counted 20 twists per metre (=1 twist per 2 ins) in a standard CAN cable product EMC test patterns max 277 wiggles per m min 20 wiggles per m (also zero wiggles per m)

6. Twists Per Unit Length EMC performance strategy: compare EMC susceptibility of EMC test patterns with an automotive standard CAN cable product Need to obtain an automotive standard CAN cable product

7. Track Width Justifications ISO11898 max CAN bus length 40m –Automotive length 5-10m –Therefore can increase resistance by factor 4-8 50 kBaud max bus length 1000m