Dynamic Tracking Bias Circuit for Simplified I/O Voltage Supply

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Solution Overview

Problem

Existing interface devices require multiple external voltages, increasing circuit complexity and manufacturing costs due to the need for additional components like ESD clamp circuits.

Innovation Solution

The interface device incorporates a dynamic tracking bias circuit that generates a first supply voltage from the main and second supply voltages, eliminating the need for an ESD clamp circuit on the first supply voltage and simplifying the circuit design by using a level shifter and output driver to provide the necessary voltage, while the second supply voltage is limited by an ESD clamp circuit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple external voltages are supplied to the interface device, then the device can perform its input/output functions, but the circuit complexity and manufacturing cost increase

Engineering Contradiction:
Improvevoltage supply capabilityVSAvoidcircuit complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent extracts the voltage generation function from external sources and implements it within the interface device itself. The dynamic tracking bias circuit generates the first supply voltage internally by tracking the second supply voltage, eliminating the need for external generation of this voltage and reducing circuit complexity while maintaining voltage supply capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The dynamic tracking bias circuit serves multiple functions: it generates the first supply voltage, tracks voltage changes of the second supply voltage, and provides this voltage to multiple circuits including the ESD clamp circuit, pre-driver, and post-driver. This multi-functionality reduces the need for separate voltage generation circuits, thereby reducing overall circuit complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If multiple external voltages are supplied to the interface device, then the device can perform its input/output functions, but the manufacturing cost increases

Engineering Contradiction:
Improvevoltage supply capabilityVSAvoidmanufacturing cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent extracts the voltage generation function from external sources and implements it within the interface device itself. The dynamic tracking bias circuit generates the first supply voltage internally by tracking the second supply voltage, eliminating the need for external generation of this voltage and reducing circuit complexity while maintaining voltage supply capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the voltage generation and regulation functions into a single dynamic tracking bias circuit. This circuit generates the first supply voltage and automatically tracks changes in the second supply voltage, eliminating the need for separate external voltage sources and reducing manufacturing complexity and cost

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If an ESD clamp circuit is added to limit the second supply voltage, then the reliability of the interface device improves, but the circuit complexity increases

Engineering Contradiction:
ImproveESD protectionVSAvoidcircuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the ESD protection function with the existing second supply voltage input. The ESD clamp circuit is integrated to limit the second supply voltage to a predetermined level, providing protection without requiring separate external protection circuits. This integrated approach maintains reliability while minimizing additional circuit complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The ESD clamp circuit automatically limits the second supply voltage to a predetermined level without requiring external control or intervention. This self-regulating protection mechanism ensures reliability while maintaining simple circuit operation

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4456432A1Interface device and dynamic tracking bias circuit
Publication Date: 2024.10.30 MEDIATEK INC
  • EP4456432A1 patent drawingFigure 1
  • EP4456432A1 patent drawingFigure 2
  • EP4456432A1 patent drawingFigure 3

AI summary

An interface device includes a dynamic tracking bias circuit, an ESD (Electrostatic Discharge) clamp circuit, a pre-driver, a post-driver, and an I/O (Input/Output) pad. The dynamic tracking bias circuit provides a first supply voltage. The first supply voltage is determined according to a main power voltage and a second supply voltage. The ESD clamp circuit limits the second supply voltage. The post-driver is driven by the pre-driver. The I/O pad is driven by the post-driver. The pre-driver and the post-driver are supplied by the main power voltage, the first supply voltage, and the second supply voltage.