Optical Transceiver Circuit Compensation for Transistor Leakage

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Solution Overview

Problem

The transceiver circuit in smartphones used for infrared remote control of home appliances is affected by electric leakage from transistors, leading to inaccurate input and output in the receiver circuit.

Innovation Solution

A transceiver circuit is designed with a compensation circuit that provides a leakage path for the first phase input terminal or injects a compensation current into the second phase input terminal, effectively canceling the leakage current and reducing its impact on the receiver circuit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the transmitter circuit uses a transistor in advanced process node (28nm or below), then the circuit can achieve higher integration and performance, but electric leakage occurs at microampere level affecting receiver accuracy

Engineering Contradiction:

Improvecircuit integration and performanceVSAvoidreceiver circuit accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The patent converts the harmful leakage current into a useful compensation signal. By intentionally generating a compensation current that mirrors the leakage current through a current mirror circuit, the leakage is transformed from a harmful effect into a beneficial counteracting signal that restores receiver accuracy.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent introduces a compensation circuit as an intermediary element between the transmitter and receiver circuits. This compensation circuit, including the compensation transistor and current mirror, acts as a mediator that isolates the receiver from the harmful effects of transmitter leakage while maintaining proper signal transmission.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Speed

If the transmitter transistor is kept on to maintain readiness, then response time is reduced, but leakage current continuously affects receiver input accuracy

Engineering Contradiction:

Improveresponse timeVSAvoidreceiver input accuracy

Core Design Contradiction:

SpeedVSMeasurement precision

Solution Approach 1:

The patent enables the transmitter circuit to remain in a ready state with the transistor continuously on, maintaining continuous readiness for transmission without interruption. The compensation circuit ensures that the continuous presence of the transistor does not degrade receiver accuracy, thus maintaining continuous useful action of the transceiver system.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The compensation circuit implements a feedback mechanism where the compensation transistor's current is adjusted based on the actual leakage current from the transmitter transistor. This feedback loop continuously counteracts the leakage effect, allowing the transmitter to remain on without compromising receiver accuracy.

Inventive Principle:

Principle #23Feedback

3Device complexity

If time division multiplexing is used for infrared transmitting and receiving functions, then device complexity is reduced, but switching between modes causes transient leakage affecting accuracy

Engineering Contradiction:

Improvecircuit architecture simplicityVSAvoidreceiver output accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The compensation circuit is activated beforehand and continuously prepared to counteract leakage currents. By having the compensation mechanism ready in advance and continuously active, the circuit cushions against transient leakage effects that occur during mode switching between transmission and reception.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent converts the transient leakage currents generated during mode switching into beneficial compensation signals. The compensation circuit captures and mirrors these transient leakage currents, transforming them from harmful disturbances into useful corrective signals that maintain accuracy during transitions.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Data Source

PatentUS12267067B2Transceiver circuit, and chip and terminal device that use transceiver circuit

Publication Date: 2025.04.01 HUAWEI TECH CO LTD

AI summary

A transceiver circuit includes a first interface and a second interface that are connected to an optical transceiver device, a receiver circuit, a transmitter circuit, and a compensation circuit. The receiver circuit includes a differential amplifier, where a first phase input terminal of the differential amplifier is coupled to the first interface, and a second phase input terminal of the differential amplifier is coupled to the second interface. The transmitter circuit includes a first transistor, where a terminal of the first transistor is coupled to the second phase input terminal, and another terminal of the first transistor is coupled to a ground terminal. The compensation circuit is configured to provide a leakage path for the first phase input terminal, or provide a compensation current for the second phase input terminal.