FYO - Re: "Fact: The K7 will use an external 2.5V supply.
Fact: The K7 will regulate this down to 1.6V internally"
Thanks.
I read the same thing 4 months ago in the AMD ISSCC paper.
1999 International Solid-State Circuits Conference
MP 5.4 A 7th-Generation x86 Microprocessor
Steven Hesley, Victor Andrade, Bob Burd, Greg Constant, Jeffrey Correll, Matthew Crowley, Michael Golden, Nancy Hopkins, Saiful Islam, Scott Johnson, Rabbani Khondker, Dirk Meyer, Jerry Moench, Hamid Partovi, Randy Posey, Fred Weber, John Yong Advanced Micro Devices, Austin, TX
"The phase-locked loop (PLL) operates with a 2.5V supply, inter-nally regulated down to 1.6V to satisfy oxide voltage stress limits. A high precision bandgap circuit minimizes variation of this internal supply voltage. Given the limited voltage headroom and the high frequency target, the PLL is designed to maximize the voltage controlled oscillator (VCO) control range. To ensure minimum static phase error over the maximum VCO control voltage range, the charge pump is designed to regulate the UP current level based on the DOWN level. This avoids large current mismatches when the UP current source devices begins to exit saturation. The cycle compression (less than 25ps) is optimized at the expense of accumulated phase error (less than 1ns) by setting the loop natural frequency low."
Paul |
