This document introduces a solution for providing power to the Pentium® processor family, including new switching regulator control circuits and linear regulators.
The document details how to design power supplies for Pentium microprocessors, specifically addressing the strict voltage requirements of the Pentium VRE processor (3.500V +100mV). It highlights the use of the LTC1266 synchronous buck regulator control chip and the LT1584 linear regulator to meet these specifications over line, load, transient, and temperature variations.
Key design considerations include handling rapid load transients where current can jump from 200mA to nearly 4A in 20ns. The text provides specific recommendations for decoupling networks, such as using four 100uF or 220uF tantalum capacitors and at least 24 pieces of 1uF ceramic capacitors. It also covers circuit board layout strategies to minimize ESR and ESL in the power network.
| Pentium processor supply requirement | 3.3V +5% |
|---|---|
| Pentium VRE processor voltage requirement | 3.500V +100mV |
| Pentium VRE total voltage tolerance | +2.9% |
| Static specifications margin for VRE | approximately +1% |
| Maximum peak transient response | 60mV |
| Minimum total network ESR for VRE | less than 0.0065Q |
The LTC1266 synchronous buck regulator control chip and the LT1584 linear regulator are recommended.
There should be a minimum of 24 pieces of a 1uF ceramic capacitor.
No, do not enable Burst Mode operation on Pentium VRE processor supplies as the circuits will not operate correctly at no load.