Voltage Regulator-Down (VRD) 10.1 Design Guide

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Design Guide 3
Contents
1
Introduction .........................................................................................................................9
1.1 Applications ............................................................................................................9
1.2 Terminology............................................................................................................9
2 Processor Vcc Requirements ...........................................................................................13
2.1 Voltage and Current (REQUIRED)................................................................13
2.2 Socket Loadline Definitions (REQUIRED) ....................................................... 13
2.3 TOB: Voltage Tolerance Band (REQUIRED)....................................................22
2.3.1 Sources of Voltage Deviation and Input Parameters ...........................22
2.3.2 TOB: Tolerance Band Calculation ........................................................ 24
2.3.3 Inductor RDC Current Sense TOB Calculations ..................................24
2.3.4 Resistor Current Sense TOB Calculations ...........................................24
2.3.5 FET RDS-ON Current Sense TOB Calculations ..................................25
2.4 Voltage Regulator Thermal Compensation (REQUIRED) ...................................25
2.5 Stability (EXPECTED) ..............................................................................26
2.6 Dynamic Voltage Identification (REQUIRED) ...................................................26
2.6.1 Dynamic-Voltage Identification Functionality........................................26
2.6.2 D-VID Validation ...................................................................................27
2.6.3 Validation Summary.............................................................................. 28
2.7 Processor Vcc Overshoot (REQUIRED).........................................................30
2.7.1 Specification Overview .........................................................................30
2.7.2 Example: Socket Vcc Overshoot Test..................................................33
2.8 VRD Output Filter (REQUIRED)..................................................................34
2.8.1 Bulk Decoupling....................................................................................34
2.8.2 High Frequency Decoupling .................................................................35
3 Vtt Requirements (REQUIRED)........................................................................................37
3.1 Electrical Specifications........................................................................................ 37
3.2 Processor-MCH Vtt Mismatch..............................................................................39
4 Power Sequencing (REQUIRED) .....................................................................................41
5 VRD Current Support (EXPECTED).................................................................................43
6 Control Inputs....................................................................................................................45
6.1 Vcc Output Enable (REQUIRED).................................................................45
6.2 Differential Remote Sense Input (REQUIRED)...................................................48
7 Input Voltage and Current.................................................................................................49
7.1 Input Voltages (EXPECTED).......................................................................49
7.1.1 Desktop Input Voltages.........................................................................49
8 Output Protection ..............................................................................................................51