Intel 315889-002 2.4Processor VCC Overshoot - REQUIRED, 2.5Impedance vs. Frequency - EXPECTED

Output Voltage Requirements

2.4Processor VCC Overshoot - REQUIRED

The VRM/EVRD 11.0 is permitted short transient overshoot events where Vcc exceeds the VID voltage when transitioning from a high-to-low current load condition (Figure 2-2). This overshoot cannot exceed VID + VOS_MAX. The overshoot duration, which is the time that the overshoot can remain above VID, cannot exceed TOS_MAX. These specifications apply to the processor die voltage as measured across the remote sense points and should be taken with the oscilloscope bandwidth setting limited to 20 MHz or 100 MHz, depending what is supported by your particular scope (with

20 MHz preference).

•VOS_MAX = Maximum overshoot voltage above VID = 50 mV

•TOS_MAX = Maximum overshoot time duration above VID = 25 µs

Figure 2-2. Processor Vcc Overshoot Example Waveform

VID + 0.050				VOS
Voltage [V]
VID - 0.000
		TOS
0	5	10	15	20	25

Time [us]

TOS: Overshoot time above VID

VOS: Overshoot voltage above VID

2.5Impedance vs. Frequency - EXPECTED

Vcc power delivery designs can be susceptible to resonance phenomena capable of creating droop amplitudes that violate the load line specification. This is due to the frequency varied PCB, output decoupling and socket impedances from the power plane layout structures. Furthermore, these resonances may not be detected through standard time domain validation and require engineering analysis to identify and resolve.

Impedance vs. Frequency, Z(f) performance simulations of the power delivery network is a strongly recommended method to identify and resolve these impedances, in addition to meeting the time domain load line in Section 2.2 and Section 2.3. The decoupling selection needs to be analyzed to ensure that the impedance of the decoupling is below the load line target up to the FBREAK (2 MHz) frequency as defined in Figure 2-3. Frequency domain load line and overshoot compliance is expected across the 0 Hz to FBREAK bandwidth. The power delivery frequency response is largely

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