On-Chip Power Monitoring via Distributed Delta-Sigma Modulators

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Solution Overview

Problem

Current IC designs face challenges in accurately monitoring power supply conditions, such as voltage level variations and noise, due to dependence on parasitic elements and process variations, leading to issues like power supply noise and increased chip area requirements for decoupling capacitance, which complicates high-speed interfaces and increases power consumption.

Innovation Solution

A distributed power supply monitoring network using small, localized delta-sigma modulators across the IC, employing decimation techniques to reduce noise and relax resolution requirements, allowing for accurate monitoring without significant power consumption or chip area increase, and utilizing digital-sized transistors and feedback control to manage power supply parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If decoupling capacitance is increased to mitigate power supply noise, then power supply noise is reduced, but chip area significantly increases

Engineering Contradiction:

Improvepower supply noiseVSAvoidchip area

Core Design Contradiction:

Object-affected harmful factorsVSArea of stationary object

Solution Approach 1:

The patent replaces the traditional decoupling capacitance approach (analog/electrical component) with a digital monitoring and control system. Delta-sigma modulators sample the power supply voltage and generate digital signals that are processed by logic circuits to control power management, substituting passive electrical components with active digital processing to reduce noise without increasing chip area

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an intermediary digital monitoring network between the power supply and the load circuits. This network of delta-sigma modulators and control logic acts as a mediator that detects power supply conditions and actively manages noise, allowing the system to maintain low noise levels without requiring large decoupling capacitance

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If decoupling capacitance is increased to mitigate power supply noise, then power supply noise is reduced, but power consumption increases due to gate leakage

Engineering Contradiction:

Improvepower supply noiseVSAvoidpower consumption

Core Design Contradiction:

Object-affected harmful factorsVSLoss of energy

Solution Approach 1:

The patent substitutes large decoupling capacitance implementations using MOS transistors with a digital monitoring and control architecture. This replacement eliminates the severe gate leakage associated with large capacitance values in advanced CMOS technologies while maintaining noise mitigation through active digital control

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Object-affected harmful factors

If excessive power supply wiring is used to reduce noise, then power supply noise is reduced, but signal routing becomes difficult and device complexity increases

Engineering Contradiction:

Improvepower supply noiseVSAvoidsignal routing complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent introduces a distributed network of delta-sigma modulators as intermediary elements throughout the IC that locally monitor and manage power supply noise. This distributed approach eliminates the need for excessive power supply wiring and complex routing, as each local monitor independently manages its region's noise conditions

Inventive Principle:

Principle #24Intermediary (Mediator)

4Reliability

If traditional power monitoring is used, then monitoring is provided, but measurement precision is insufficient due to parasitic elements and process variations

Engineering Contradiction:

Improvepower supply monitoring accuracyVSAvoidvoltage monitoring precision

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent divides the power supply monitoring function into multiple distributed delta-sigma modulators placed throughout the IC. Each modulator independently samples the local power supply voltage, and their results are combined through digital processing. This segmentation approach compensates for local parasitic effects and process variations that would affect a single centralized monitor

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements feedback control where the delta-sigma modulators continuously sample the power supply voltage and feed this information back to control logic. The control logic adjusts power management based on the sampled values, creating a closed-loop system that maintains high measurement precision despite parasitic elements and process variations

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS8471720B2On-chip power supply monitoring using a network of modulators

Publication Date: 2013.06.25 AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE LTD

AI summary

An apparatus for monitoring at least supply voltage in an IC includes a plurality of monitor circuits distributed throughout the integrated circuit. Each of the monitor circuits is operative to receive the supply voltage, or a signal representative thereof, and to generate an output signal indicative of a comparison between the supply voltage and a reference voltage. The apparatus further includes a control circuit coupled to the plurality of monitor circuits. The control circuit is operative to receive the respective output signals from the plurality of monitor circuits and to generate an output of the apparatus which is a function of information conveyed in the respective output signals from the plurality of monitor circuits.