Programmable Current Mirror With Non-Volatile Threshold Control

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Solution Overview

Problem

Current mirrors in analog circuits lack the ability to dynamically and non-volatilely adjust the mirroring ratio without relying on externally stored binary control bits.

Innovation Solution

A current mirror circuit incorporating a programmable transistor with an adjustable threshold voltage, coupled with an enable and programming switch, allowing for dynamic control of the mirroring ratio through electric field-induced threshold voltage switching using ferroelectric or charge trap field effect transistors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If externally stored binary control bits are used to dynamically control the mirroring ratio, then the mirroring ratio can be adjusted, but the flexibility and programmability are limited

Engineering Contradiction:

ImproveprogrammabilityVSAvoidcontrol mechanism complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent changes the threshold voltage parameter of the transistor dynamically through electrical field induction from control gates, rather than using fixed binary control bits. This allows continuous adjustment of the mirroring ratio by varying the threshold voltage, providing analog-like programmability without digital quantization limits.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical/electrical switch-based binary control system with an electric field-induced threshold voltage modulation system. Instead of using switches to select discrete transistor configurations, the invention uses control gates to induce electric fields that continuously adjust the threshold voltage, thereby replacing a discrete control mechanism with a continuous field-based control mechanism.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If conventional current mirror circuits are used, then the circuit structure is simple, but non-volatile adjustments to the output current are not provided

Engineering Contradiction:

Improvenon-volatile storageVSAvoidcircuit structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The programmable transistor structure is self-programming through electric field induction from control gates. The threshold voltage is adjusted by applying voltages to the control gates, which induce electric fields that modulate the channel conductivity. This self-adjusting mechanism eliminates the need for external programming circuits or memory elements, allowing the transistor to program itself.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The control gates serve multiple functions: they control the threshold voltage for current mirroring, provide non-volatile storage capability through electric field retention, and enable dynamic reconfiguration of the circuit. This multi-functionality integrates what would traditionally require separate components into a single unified structure.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If switches controlled by externally stored binary control bits are used, then the number of active output FETs can be changed, but the control mechanism becomes complex and less flexible

Engineering Contradiction:

Improvedynamic controlVSAvoidcontrol operation

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent replaces the switch-based discrete control mechanism with electric field-induced continuous control. Instead of using multiple switches to select between different FET configurations, the invention uses control gates to induce electric fields that continuously modulate the threshold voltage, providing smooth and flexible control without discrete switching artifacts.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the control parameter from discrete binary control bits to continuous threshold voltage through electric field induction. By varying the voltage on control gates, the threshold voltage is continuously adjusted, enabling fine-grained control of the mirroring ratio without the quantization and switching delays inherent in binary control systems.

Inventive Principle:

Principle #35Parameter changes

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 precise and non-volatile adjustment of output current without external control bits, enhancing the flexibility and efficiency of current mirroring in analog circuits.

Implementation Method 1

using ferroelectric or charge trap field effect transistors for electric field-induced threshold voltage switching

Methodology Applied

Scientific EffectElectric field-induced threshold voltage switching: Electric Field

Data Source

PatentUS12386379B2Non-volatile current mirror circuit with programmable transistor

Publication Date: 2025.08.12 GLOBALFOUNDRIES US INC

AI summary

Embodiments of the present disclosure provide a structure, including: a current mirror; a programmable transistor with an adjustable threshold voltage connected in parallel with an output transistor of the current mirror; an enable switch for coupling the current mirror to a gate of the programmable transistor; and a programming switch coupled to the gate of the programmable transistor.