Voltage Regulator-Down (VRD) 10.1 Design Guide

Processor Vcc Requirements
R
Design Guide
33
Figure 2-11. Example Socket Vcc Overshoot Waveform
2.7.2 Example: Socket Vcc Overshoot Test
To pass the overshoot specification, the amplitude constraint of Equation 2-4 and time duration
requirement of TOS_MAX must be satisfied. This example references Figure 2-11.
Amplitude Test Constraint: Overshoot amplitude, VOS, must be less than Vzc + VOS_MAX
Input parameters
VOS= 1.325 V – Obtained from direct measurement
V
ZC
= 1.285 V – Obtained from direct measurement
VOS_Max = 0.050 V – An Intel specified value
Amplitude Analysis:
V
ZC
+ VOS_MAX = 1.285 V + 0.050 V = 1.335 V
VOS = 1.325 < 1.335 V
Amplitude Test Satisfied
Time Duration Test Constraint: Overshoot duration above Vzc must be less than 25
µs
Input Parameters
Initial crossing of overshoot: 15
µs – Obtained from direct measurement
Final crossing of overshoot: 35
µs – Obtained from direct measurement
TOS_MAX = 25
µs – An Intel specified value