Tri-State Driver Circuit Using Delayed Input for High-Impedance

Solution Overview

Problem

Conventional tri-state driver circuits in high-speed integrated circuits require additional circuitry and power to manage a separate enable signal, leading to increased substrate area consumption and power usage due to complex timing coordination.

Innovation Solution

A signal driver circuit that provides automatic tri-state control without a separate enable signal, using a delay line and complementary transistors to manage logic levels and impedance states, allowing the true input signal and its complement to control the circuit's operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a separate enable signal is used to control the high-impedance state of the driver circuit, then the driver circuit can be tri-stated, but additional circuitry is required that consumes substrate area and electrical power

Engineering Contradiction:

Improvetri-state capabilityVSAvoidsubstrate area

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent merges the enable function with the existing data input circuitry. The enable signal is combined with the data signal path through logic gates (AND/OR gates) so that the same circuit elements that process data also control the tri-state function. This eliminates the need for separate enable signal circuitry and reduces substrate area while maintaining tri-state capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent makes the data input circuitry multi-functional by having it serve both data processing and enable control functions. The circuit elements process data signals during active periods and simultaneously generate enable control signals for the output stage, allowing one set of circuitry to perform multiple functions and reduce overall area.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If a separate enable signal is used to control the high-impedance state of the driver circuit, then the driver circuit can be tri-stated, but additional circuitry is required that consumes electrical power

Engineering Contradiction:

Improvetri-state capabilityVSAvoidelectrical power

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by stationary object

Solution Approach 1:

The patent merges the enable function with the existing data input circuitry. The enable signal is combined with the data signal path through logic gates (AND/OR gates) so that the same circuit elements that process data also control the tri-state function. This eliminates the need for separate enable signal circuitry and reduces substrate area while maintaining tri-state capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent makes the data input circuitry multi-functional by having it serve both data processing and enable control functions. The circuit elements process data signals during active periods and simultaneously generate enable control signals for the output stage, allowing one set of circuitry to perform multiple functions and reduce overall area.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If a separate enable signal is used to control the high-impedance state of the driver circuit, then the driver circuit can be tri-stated, but complex timing coordination is required to prevent interference with output signal driving

Engineering Contradiction:

Improvetri-state controlVSAvoidtiming coordination circuitry

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the enable function with the existing data input circuitry. The enable signal is combined with the data signal path through logic gates (AND/OR gates) so that the same circuit elements that process data also control the tri-state function. This eliminates the need for separate enable signal circuitry and reduces substrate area while maintaining tri-state capability.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The circuit automatically generates the enable control signal from the data input signals themselves through the logic gate combinations. The circuit serves itself by using its own input signals to control its output stage, eliminating the need for external enable signal generation and complex timing coordination circuitry.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS8750014B2Tri-state driver circuits having automatic high-impedance enabling

Publication Date: 2014.06.10 MICRON TECHNOLOGY INC

AI summary

Memories, driver circuits, and methods for generating an output signal in response to an input signal. One such driver circuit includes an input stage and an output stage. The input stage receives the input signal and provides a delayed input signal having a delay relative to the input signal. The output stage receives the delayed input signal and further receives the complement of the input signal. The output stage couples an output node to a first voltage in response to a complement of the input signal having a first logic level and couples the output to a second voltage in response to the complement of the input signal having a second logic level. The output stage further decouples the output from the first or second voltage in response to receiving the delayed input signal to provide a high-impedance at the output node.