{"id":3329,"date":"2025-09-18T22:28:30","date_gmt":"2025-09-18T22:28:30","guid":{"rendered":"https:\/\/www.inneos.com\/?p=3329"},"modified":"2026-02-06T20:48:33","modified_gmt":"2026-02-06T20:48:33","slug":"optical-vs-copper-automotive-networks","status":"publish","type":"post","link":"https:\/\/www.inneos.com\/optical-vs-copper-automotive-networks\/","title":{"rendered":"Optical vs. Copper: Power Efficiency at 25G in Automotive Networks"},"content":{"rendered":"\n

As vehicles shift toward <\/span>software-defined architectures<\/span> and <\/span>autonomous driving<\/span>, the amount of data moving around inside the car is exploding. Cameras, radar, LIDAR, infotainment, and advanced driver assistance systems all need massive bandwidth with little tolerance for latency. That\u2019s why the industry is now looking to <\/span>25G Ethernet links<\/span> as the backbone of in-vehicle networks.<\/span> <\/span><\/p>\n\n\n\n

But there\u2019s a catch: power consumption. In a car, every watt matters. Higher PHY<\/a> power doesn\u2019t just mean higher operating costs\u2014it means more heat inside compact electronic control units (ECUs), more complex cooling requirements, and greater load on already limited vehicle power budgets (especially in EVs). So how do we connect vehicles at 25G without blowing the power and thermal budget? The answer lies in the choice between copper vs. optical. <\/span><\/p>\n\n\n\n

Why Power is Such a Big Deal in Cars<\/span><\/b> <\/span><\/h3>\n\n\n\n
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Unlike a data center, where you can scale cooling and power delivery at the rack level, vehicles have tight design envelopes. Power for high-speed links must compete with the needs of drive motors, sensors, and all of the modern infotainment and displays of modern vehicles. <\/span><\/p>\n\n\n\n

Copper PHYs at 25G work hard to overcome insertion loss in automotive-qualified cables. They rely on <\/span>high-swing transmitters<\/span> and <\/span>complex equalization circuits<\/span> at the receiver. Both of those burn power\u2014and the longer the link, the worse it gets.<\/span> <\/span><\/p>\n\n\n\n

Optical links, on the other hand, barely notice the extra distance. A VCSEL transmitter and TIA receiver can deliver clean 25G signals over lightweight fibers with <\/span>much lower PHY power<\/span>. Plus, optics are immune to <\/span>electromagnetic interference (EMI)<\/span>\u2014a huge benefit in the electrically noisy environment of a car.<\/span> <\/span><\/p>\n<\/div><\/div>\n\n\n\n

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Breaking Down the PHY Power at 25G<\/span><\/b> <\/span><\/h3>\n\n\n\n

Here\u2019s where the power goes in a 25G Ethernet PHY:<\/span> <\/span><\/p>\n\n\n\n