I have a board here which accepts only 3.3v PCI cards and I've found several on ebay which will fit. But the spec according to Wikipedia says that USB requires 5v. How is this possible? 😐
Well the 3.3/5v thing for PCI is the I/O voltage, the voltage that the card uses to talk to the motherboard/chipset. Generally all PCI cards have a +5v available, just not always used for the I/O voltage.
Otherwise, they can use a boost converter, which is like your main power supply except instead of lowering voltage (a buck converter), they raise it (a boost converter).
My initial response was incomplete, please make sure you've read my edited post.
Yes, I always ramble this much.
wrote:I have a board here which accepts only 3.3v PCI cards and I've found several on ebay which will fit. But the spec according to Wikipedia says that USB requires 5v. How is this possible? 😐
PCI slot has access to all sorts of voltages including +12V, +5V, -12V, etc.
In contrast, PCI-E slot lacks +5V connection and that's why you almost always see a molex connector on a PCI-E to USB adapter.
