Operating A Philips CD-i Off USB-C

The Philips CD-i is a console with many shortcomings, and people embrace the facility provide. For no matter purpose, the engineering staff determined it ought to use an 8P8C connector identical to Ethernet. Thus, identical to your Ethernet cables, it has that annoying drawback of the tab snapping off on a regular basis. [MattKC] questioned if the CD-i may gain advantage from a USB energy improve as a substitute, and set about making it a reality.

The plan was easy sufficient—get the CD-i operating off of USB-C as a substitute of the ungainly unique energy provide that shipped with the unit. Given the console runs virtually completely off of 5 V energy, it ought to have been fairly straightforward. Only, the unique spec provides one little element that makes issues a bit tougher. The console is designed to attract as much as 3 A from the 5 V line, whereas additionally having a -5 V line at 0.2 A. If not for that unfavorable provide, it will have been straightforward to run the unit off any outdated 15 W USB-C charger spitting out 5 V. That further unfavorable line complicates issues, as a result of whereas the unfavorable line may very well be created with some supporting electronics, it’s exhausting to search out that further watt from most chargers. While there are many higher-wattage USB-C chargers, the bulk have a tendency to make use of larger voltages to ship the extra energy, capping the 5 V output at 3 amps.

Thus, it was essential to work somewhat tougher. [MattKC] determined to construct a board that may negotiate with a USB-C charger for 9 V operation to get the facility funds essential. This would then be stepped down to five V, whereas there would even be an inversion step to produce the -5 V line, too. A CH221K chip does the job of negotiating a 9 V USB-C energy provide, whereas a TPSM84538 steps the voltage down to five V with the capability to produce as much as 5 A. An LT3580 chip then inverts this voltage for the 5 V line. There’s additionally an influence switching circuit on board as a result of the CD-i included a few of that performance within the unique energy brick.

If you’ve received a CD-i and also you’re sick of fussing with the unique energy provide, this may very well be a fantastic improve. We’ve also explored USB Power Delivery in detail before, if you need a primer.