3 ms·
Hi, I've been trying to figure this out for a while, and it's a hell of a thing to get Google to understand. Can someone explain why the rail is referred to as
by jamesaguilar 12y ago
Hi, I've been trying to figure this out for a while, and it's a hell of a thing to get Google to understand. Can someone explain why the rail is referred to as "-5v" instead of its opposite simply being called "5v"?
- rrmm 12y agoThe power supply output 12, 5, -5, -12 volts. -5v rail was for the DRAM.
- pjc50 12y agoBecause it's 5V below the "ground"/0V rail which most things are referenced to. It's very inconvenient to keep referring to the 17V rail and the 10V rail above the 5V return rail, so you call those 12V, 5V and 0V. The majority return current is in the 0V rail. The -5V rail supplies (conventional) current which also returns to the 0V rail. (In fact there is usually very little current in the -5V rail, just leakage through transistors; it's used as a bias voltage for the DRAM substrate. http://books.google.co.uk/books?id=TgW3LTubREQC&pg=PA158&lpg=PA158&dq=use+of+negative+voltage+in+dram&source=bl&ots=l0IvmAMlsi&sig=0Elvj-h3RBqOJ0JAKP43d2xA8YY&hl=en&sa=X&ei=u_JZVO3JA8rY7Aa8joCIDg&ved=0CCsQ6AEwAg#v=onepage&q=use%20of%20negative%20voltage%20in%20dram&f=false http://books.google.co.uk/books?id=TgW3LTubREQC&pg=PA158&lpg... )