Self-referenced on-die voltage droop detector

1. A system for detecting voltage droops, comprising:

a voltage reference generator component comprising a low-pass filter component and a unity-gain amplifier, wherein the voltage reference generator is configured to convert a supply voltage of a power distribution network of an integrated circuit to a reference voltage, wherein the low-pass filter component is configured to perform low-pass filtering on at least a portion of the supply voltage to yield a filtered voltage, and wherein the unity-gain amplifier is configured to output, as the reference voltage, a buffered version of the filtered voltage; and

a comparator component configured to generate a comparison result output signal in response to a determination that a transient voltage representing the supply voltage has deviated from the reference voltage in excess of a margin.

2. The system of claim 1 , further comprising a sampling component configured to synchronously sample the comparison result output signal and to generate a droop detection signal in response to detection of the comparison result output signal.

3. The system of claim 2 , further comprising a logic control component configured to modify a frequency of a system clock signal in response to detection of the droop detection signal.

4. The system of claim 1 , wherein the low-pass filter is configured to produce, as the filtered voltage, a transiently averaged sampled output of at least the portion of the supply voltage over time.

5. The system of claim 1 , wherein the voltage reference generator component further comprises a voltage divider component configured to divide the supply voltage into a bus of different voltages, and wherein at least the portion of the supply voltage is a voltage of the bus of different voltages.

6. The system of claim 5 , wherein the transient voltage comprises another voltage of the bus of different voltages.

7. The system of claim 1 , wherein the voltage reference generator component, the comparator component, the low-pass filter component, and the unity-gain amplifier component are on-die components of the integrated circuit.

8. The system of claim 1 , wherein the low-pass filter component is configured to perform time-averaging of at least the portion of the supply voltage to yield the filtered voltage.

9. A method of detecting droops in supply voltage, comprising:

converting, by one or more on-die components of an integrated circuit, a supply voltage of a power distribution network of an integrated circuit to a reference voltage, wherein the converting comprises performing a low-pass filtering on at least a portion of the supply voltage to yield a filtered voltage and generating, as the reference voltage, a buffered version of the filtered voltage; and

generating, by the one or more on-die components, a comparison result signal in response to determining that a transient voltage representing the supply voltage has deviated from the reference voltage in excess of a margin.

10. The method of claim 9 , further comprising:

synchronously sampling, by the one or more on-die components, the comparison result signal; and

outputting, by the one or more on-die components, a droop detection signal in response to detecting the comparison result signal.

11. The method of claim 10 , further comprising modifying, by the one or more on-die components, a frequency of a system clock signal used by the integrated circuit in response to detecting the droop detection signal.

12. The method of claim 9 , wherein the performing the low-pass filtering comprises performing a transient averaged sampling of at least the portion of the supply voltage over time.

13. The method of claim 9 , wherein the converting further comprises dividing the supply voltage to yield a bus of different voltages, and wherein at least the portion of the supply voltage is one of the different voltages.

14. The method of claim 13 , wherein the transient voltage comprises another of the different voltages.

15. The method of claim 9 , wherein the performing the low-pass filtering comprises performing time-averaging of at least the portion of the supply voltage to yield the filtered voltage.

16. An integrated circuit, comprising:

a power distribution network that provides a supply voltage to one or more integrated components of the integrated circuit;

a voltage divider component configured to divide the supply voltage into a bus of different voltages;

a low-pass filter component configured to generate a transiently averaged sampled version of a first voltage of the bus of different voltages, wherein the low-pass filter component filters the transiently averaged sampled version of the first bus voltage to approximately one-tenth of system resonant frequency to yield a filtered voltage;

a unity-gain amplifier component configured to buffer the filtered voltage to yield a reference voltage;

a comparator component configured to compare the reference voltage with a second voltage of the bus of different voltages and to generate a comparison result signal in response to determining that the second voltage has deviated from the reference voltage in excess of a tolerance; and

a sampling component configured to synchronously sample the comparison result signal and to output a droop detection signal in response to detecting the comparison result output signal.

17. The integrated circuit of claim 16 , further comprising a logic control component configured to adjust a frequency of a system clock signal in response to detecting of the droop detection signal.

18. The integrated circuit of claim 16 , wherein the low-pass filter component comprises a set of series-connected metal-oxide-semiconductor field-effect transistors (MOSFETs) in series to a capacitor, a first switched capacitor connected through a first switch to a first node that connects one of the series-connected MOSFETS to the capacitor, and a second switched capacitor connected through a second switch to a second node that connects the first switched capacitor to the first switch.