VRM 9.0 DC-DC Converter Guidelines
Voltage and Current REQUIRED
The voltage regulator module (VRM) 9.0 is a DC-DC converter that supplies the required voltage and current to a single processor. The maximum voltage is determined by the five-bit voltage identification (VID) code provided to the VRM. The computer system board ...must supply additional decoupling capacitance and sufficient plane area to carry the high DC currents. It is desirable that a single model of the VRM be able to support all processor types, if this does not significantly affect VRM cost and availability, so that field upgrades of processors will not require a new VRM.
Output Voltage Tolerance REQUIRED
The voltage measured at the VRM connector pins on the system board must be within the range shown in Table 1, except during input voltage turn-on and turn-off. Voltage tolerance includes:
• Initial DC output voltage set-point error
• Component aging effects
• Output ripple and noise
• Full ambient temperature range and warm up.
• Both static operation and dynamic output load changes from minimum-to-maximum or maximum-to-minimum loads specified in the tables.
Output voltage tolerances increase with output current levels to compensate for the increasing voltage drops in the power distribution path. Table 1 shows the relationship of VCC_CORE (measured at the processor pins) and ICC for different processors.
Read the full VRM 9.0 DC-DC Converter Guidelines.