Galvanically Isolated Interface Circuit for Sleep-Mode Wake-Up

Solution Overview

Problem

Bus interface circuits with galvanic isolation face challenges in transmitting wake-up events across voltage domains during sleep mode, as the communication channel is inactive, preventing information about wake-up events from being transmitted to other domains.

Innovation Solution

Incorporating additional receiver circuits optimized for low power draw, which remain active in sleep mode and can receive wake-up request signals via galvanically isolating devices like coreless transformers, allowing for the transmission of wake-up signals across voltage domains.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the bus interface circuit operates in sleep mode to reduce power consumption, then power draw is reduced, but the transmission channel via galvanic isolation becomes unavailable preventing wake-up event communication

Engineering Contradiction:

Improvepower drawVSAvoidwake-up event transmission

Core Design Contradiction:

Use of energy by moving objectVSLoss of information

Solution Approach 1:

The receiver circuit is divided into two independent parts: a first receiver circuit that is deactivated in sleep mode to save power, and a second receiver circuit that remains active to detect wake-up events. This segmentation allows the system to maintain wake-up functionality while minimizing power consumption by only keeping the essential wake-up detection circuitry active.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The second receiver circuit acts as an intermediary between the galvanically isolated transmission channel and the main receiver circuit. It receives wake-up events during sleep mode and triggers the activation of the first receiver circuit and normal operation, thereby mediating the transition from low-power to full-operation state.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Use of energy by moving object

If the first receiver circuit is deactivated in sleep mode to save power, then power consumption is reduced, but wake-up events cannot be received or transmitted to other domains

Engineering Contradiction:

Improvepower consumptionVSAvoidwake-up event detection

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The receiver circuit is divided into two independent parts: a first receiver circuit that is deactivated in sleep mode to save power, and a second receiver circuit that remains active to detect wake-up events. This segmentation allows the system to maintain wake-up functionality while minimizing power consumption by only keeping the essential wake-up detection circuitry active.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The second receiver circuit acts as an intermediary between the galvanically isolated transmission channel and the main receiver circuit. It receives wake-up events during sleep mode and triggers the activation of the first receiver circuit and normal operation, thereby mediating the transition from low-power to full-operation state.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Loss of information

If additional receiver circuits are added to maintain wake-up functionality during sleep mode, then wake-up event transmission is enabled, but device complexity increases

Engineering Contradiction:

Improvewake-up event communicationVSAvoidcircuit structure

Core Design Contradiction:

Loss of informationVSDevice complexity

Solution Approach 1:

The wake-up detection functionality is extracted from the main receiver circuit and implemented as a separate second receiver circuit. This extraction allows the main receiver circuit to be fully deactivated in sleep mode while maintaining wake-up detection capability through the simplified second receiver circuit, reducing the complexity burden on the main communication path.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The second receiver circuit implements a simplified copy of the wake-up detection functionality needed during sleep mode. Rather than maintaining the full capabilities of the first receiver circuit, only the essential wake-up event detection and transmission capabilities are copied into the second receiver circuit, reducing overall complexity while maintaining necessary functionality.

Inventive Principle:

Principle #26Copying

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

Enables the detection and transmission of wake-up events across voltage domains, facilitating a seamless transition from sleep mode to normal operation without increasing power consumption, thus maintaining low power draw while ensuring timely communication.

Implementation Method 1

a galvanically isolating device (21) that isolates a first voltage domain from a second voltage domain

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS10921769B2Interface circuit

Publication Date: 2021.02.16 INFINEON TECHNOLOGIES AG

AI summary

The description that follows relates to a circuit having galvanic isolation. According to an exemplary embodiment, the circuit has a transmission circuit, coupled to a galvanically isolating device, that is designed to transmit a first signal via the galvanically isolating device. The circuit further has a first receiver circuit, coupled to the galvanically isolating device, that is designed to receive the transmitted first signal from the galvanically isolating device. A second receiver circuit coupled to the galvanically isolating device is designed to receive the transmitted first signal from the galvanically isolating device and to take the received first signal as a basis for generating a wake-up signal.