Y-bridge driver short detection and protection circuit

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Solution Overview

Problem

Existing audio device transducer driver systems face challenges in detecting and protecting against electrical shorts between power supplies, which can lead to component damage due to increased voltage.

Innovation Solution

A system with a detection and protection circuit that monitors the second supply voltage and electrically isolates the output terminal from the second supply voltage when it exceeds an overvoltage threshold, using a first and second switch to manage supply voltages and prevent electrical shorts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If multiple supply voltages are used for an amplifier to reduce power consumption, then power efficiency is improved, but the risk of electrical shorts between supplies increases

Engineering Contradiction:

Improvepower consumptionVSAvoidelectrical short risk

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The detection circuit continuously monitors the voltage potential difference between multiple supply rails before electrical shorts can occur. By detecting overvoltage conditions on the second supply voltage in advance, the system can preventive action by opening isolation switches before damage happens to other components.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Isolation switches are introduced as intermediary elements between the first and second supply voltages. These switches act as controllable barriers that can electrically isolate the supplies when needed, preventing direct current flow between them while allowing normal operation when supplies are safe.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If electrical short detection is implemented to protect components, then component safety is improved, but circuit complexity increases

Engineering Contradiction:

Improvecomponent protectionVSAvoiddetection circuit complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The detection circuit is designed to monitor multiple supply voltages simultaneously using a unified approach. The same detection mechanism and isolation switches serve dual purposes: normal voltage regulation and fault detection/protection, eliminating the need for separate protection circuits.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The detection circuit automatically monitors its own supply voltages and triggers protective isolation switches when abnormalities are detected. The system performs self-diagnosis and self-protection without requiring external intervention or complex external protection circuits.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS11316508B2Detection and protection of short between power supplies in a Y-bridge driver

Publication Date: 2022.04.26 CIRRUS LOGIC INC

AI summary

A system may include an output driving stage comprising a first switch configured to selectively open and close an electrical path between a first supply voltage and an output terminal of the output driving stage and a second switch configured to selectively open and close an electrical path between a second supply voltage and the output terminal of the output driving stage, wherein the second supply voltage is lower than the first supply voltage. The system may also include detection and protection circuitry configured to monitor a physical quantity indicative of the second supply voltage and responsive to the physical quantity exceeding an overvoltage threshold, electrically isolate the output terminal from the second supply voltage.