Self-Sensing Reverse Current Protection Circuit for Deep Sleep Power Management

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Solution Overview

Problem

Existing reverse current protection methods for integrated circuits are either costly, require additional terminals and control signals, or necessitate reprogramming of remote integrated circuits, leading to inefficiencies and erroneous operations due to power wastage and faults during deep sleep modes.

Innovation Solution

A self-sensing reverse current protection circuit with an RCP switch that automatically opens during deep sleep mode to prevent reverse current flow, using a reference voltage circuit and control circuit to manage the switch state without additional terminals or control signals, ensuring the power supply rail remains discharged.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the integrated circuit is powered down in deep sleep mode to save power, then power consumption is reduced, but reverse current flows through the ESD diode causing power wastage and potential faults

Engineering Contradiction:
Improvepower consumptionVSAvoidreverse current power wastage
Core Design Contradiction:
Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The RCP circuit automatically detects the power supply voltage state and controls the RCP switch without external intervention. The control circuit monitors the power supply rail voltage and autonomously opens the RCP switch when voltage drops below the reference level, preventing reverse current without requiring programming or external control signals

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The control circuit continuously monitors the power supply voltage and compares it against a reference voltage to determine when to open or close the RCP switch. This feedback mechanism ensures the switch state dynamically responds to power supply conditions, automatically preventing reverse current during deep sleep mode while maintaining normal operation when powered

Inventive Principle:
Principle #23Feedback

2Reliability

If external components or head switches are added to prevent reverse current, then reverse current protection is improved, but manufacturing cost and device complexity increase

Engineering Contradiction:
Improvereverse current protectionVSAvoidadditional terminals and control signals
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The RCP functionality is integrated directly into the existing power supply network of the integrated circuit. The RCP switch is inserted in series with the power supply rail, and the control circuit uses existing voltage nodes (power supply rail and buffer power supply node) for its operation, eliminating the need for separate external protection components or additional control terminals

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The RCP circuit serves multiple functions: it protects against reverse current during deep sleep mode, maintains normal power supply during operation, and does so using the existing power supply infrastructure of the integrated circuit without requiring dedicated protection terminals or external components

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively prevents reverse current-induced power wastage and faults, maintaining the power supply rail discharged even when the integrated circuit is in deep sleep mode, without the need for reprogramming or additional components, resulting in a compact and low-power solution.

Implementation Method 1

the ESD diode becomes forward-biased and safely discharges the electrostatic charge to the power supply rail

Methodology Applied
Scientific EffectElectrostatic discharge: Electrostatic Discharge

Implementation Method 2

a reference voltage circuit having a capacitor charged by the power supply voltage to generate a reference voltage. The capacitive storage in the reference voltage circuit causes the reference voltage to become greater than the power supply voltage when the power supply voltage is collapsed

Methodology Applied
Scientific EffectCapacitive storage: Capacitance

Data Source

PatentEP3251150B1Self-sensing reverse current protection switch
Publication Date: 2018.12.19 QUALCOMM INC
  • EP3251150B1 patent drawingFigure 1
  • EP3251150B1 patent drawingFigure 2
  • EP3251150B1 patent drawingFigure 3

AI summary

A reverse current protection (RCP) circuit is provided that includes an RCP switch coupled between a power supply rail and a buffer power supply node. A control circuit powered by a buffer supply voltage on the buffer power supply node controls the RCP switch to open in response to a discharge of a power supply voltage carried on the power supply rail.