Embedded Voltage Regulator-Down (EmVRD) 11.0 Design Guidelines for Embedded Implementations Supporting PGA478

Embedded Voltage Regulator-Down (EmVRD) 11.0

January 2007 Design Guidelines for Embedded Implementations

2.0—EmVRD 11.0

2.6.2 Example: Processor V

Overshoot Test

To pass the overshoot specification, the amplitude constraint of Equation 4 and time

duration requirement of TOS_MAX must be satisfied. This example references Figure 9.

Amplitude Test Constraint: Overshoot amplitude, VOS, must be less than Vzc +

VOS_MAX

Input parameters:

• VOS= 1.325V: Obtained from direct measurement

• VZC = 1.285V: Obtained from direct measurement

• VOS_MAX = 0.050V: An Intel specified value

Amplitude Analysis:

• VZC + VOS_MAX = 1.285 V + 50 mV = 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

Overshoot Duration Analysis:

• TOS = Final Crossing of Vzc: Initial Crossing of Vzc

•TOS = 35

µs – 15 µs = 20 µs < 25 µs = TOS_MAX

Time duration test passed:

• Amplitude and Time Duration Tests Passed => Overshoot specification is satisfied

Figure 9. Example Processor V

Overshoot Waveform