Multi-Swing I/O Circuit with Separate 1.2V and 1.8V Signal Chains

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Solution Overview

Problem

Integrated circuits (ICs) face challenges in supporting multiple input-output (I/O) logic-level swings, requiring programmability to generate and receive signals with different voltage levels without compromising performance or increasing power consumption.

Innovation Solution

The implementation of separate output and input signal chains within the IC, each tailored for specific voltage levels (1.2V and 1.8V), with a logic block that controls the mode signal to enable or disable the appropriate signal chain for generating or processing signals, and a multiplexer for input signals to select the appropriate output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a single I/O circuit is designed to support multiple logic-level swings, then the adaptability of the I/O circuit is improved, but the device complexity increases

Engineering Contradiction:

Improvesupport for multiple logic-level swingsVSAvoidprogrammability requirements

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The I/O circuit is divided into separate first and second output signal chains, each dedicated to a specific logic-level swing (first and second logic-level swings respectively). This segmentation allows each chain to be optimized for its specific voltage level while the overall circuit supports multiple swings through selective activation based on mode signals.

Inventive Principle:

Principle #1Segmentation

2Reliability

If separate signal chains are used for different voltage levels, then the reliability is improved, but the device complexity increases

Engineering Contradiction:

Improveoperational reliabilityVSAvoidmultiple signal chains

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Multiple output signal chains are designed with identical structural configurations, each capable of performing the same output function but optimized for different voltage levels. This universal design approach improves reliability by ensuring consistent performance across different logic-level swings while maintaining design efficiency.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The I/O circuit dynamically selects which output signal chain to activate based on the required logic-level swing, controlled by mode signals. This dynamic switching capability allows the circuit to adapt its internal configuration to match the external requirements, ensuring optimal reliability for each operating condition without permanently committing to a fixed structure.

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If programmability is added to support multiple logic-level swings, then the adaptability is improved, but the ease of operation deteriorates

Engineering Contradiction:

Improveprogrammable logic-level swingsVSAvoidconfiguration complexity

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The I/O circuit automatically configures itself by selecting the appropriate output signal chain based on incoming mode signals, without requiring manual intervention or complex external configuration. The circuit self-adjusts its internal state to match the required logic-level swing, simplifying operation while maintaining full adaptability.

Inventive Principle:

Principle #25Self-service

4Reliability

If multiple input signal chains are implemented, then the reliability is improved, but the use of energy increases

Engineering Contradiction:

Improvesignal processing reliabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The I/O circuit activates only the specific input signal chain required for the current operating mode, rather than continuously operating all chains. This periodic activation based on mode signals ensures that energy is consumed only when needed for the specific logic-level swing being processed, reducing overall power consumption while maintaining reliability through selective signal chain engagement.

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS8179160B1Input-output (I/O) circuit supporting multiple I/O logic-level swings

Publication Date: 2012.05.15 TEXAS INSTRUMENTS INC

AI summary

An integrated circuit (IC) includes an input/output (I/O) circuit supporting high-speed operation and multiple I/O logic-level swings. The I/O circuit includes a first output signal chain to generate outputs with a first logic level swing, and a second output signal chain to generate outputs with a second logic level swing. The outputs of the first output signal chain and the second output signal chain are connected to a same output pad of the IC. Transistors in the first output signal chain and the second output signal chain are fabricated using corresponding gate oxide characteristics. The second output signal chain includes protection circuitry to prevent transistors in the second output signal chain from being subjected to voltage stresses beyond a safe limit. An input circuit in the I/O circuit similarly includes multiple input signal chains to enable reception of input signals of different logic-level swings from a same input pad.