Bias Current Calibration Circuit for Process-Independent IC Operation

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Solution Overview

Problem

Semiconductor devices require both process-dependent and process-independent bias currents to compensate for fabrication process variations, necessitating complex and costly current/voltage generating elements with high manufacturing complexity.

Innovation Solution

An integrated circuit with a bias current generating device that includes a peripheral circuit, multiple bias current generators, and a calibration mechanism using a variable resistor and electrical fuse to generate and calibrate bias currents, allowing for reduced complexity and expandability by storing calibration codes and adjusting resistance values based on external standards.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple bias current generators with calibration mechanisms are implemented to compensate for fabrication process variations, then the operating reliability is improved, but the device complexity increases

Engineering Contradiction:

Improveoperating reliabilityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The bias current generation is divided into multiple independent generators (first bias current generator, second bias current generator, third bias current generator), each responsible for specific current paths. This segmentation allows calibration of individual generators without affecting others, improving reliability while managing complexity through modular design

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Calibration codes are stored in advance in electrical fuses during manufacturing, and variable resistors are pre-configured with calibration mechanisms. This preliminary calibration action eliminates the need for complex runtime calibration circuits, improving reliability through pre-established accuracy while reducing operational complexity

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If calibration mechanisms with variable resistors and electrical fuses are used to generate process-independent bias currents, then the manufacturing precision is improved, but the ease of manufacture deteriorates

Engineering Contradiction:

Improvemanufacturing precisionVSAvoidease of manufacture

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

Electrical fuses are used as one-time programmable calibration storage elements that are simple and inexpensive to manufacture. These fuses store calibration codes permanently, providing high manufacturing precision for bias current generation without requiring complex, expensive reconfigurable components

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

Variable resistors are used to adjust resistance values based on calibration codes, enabling precise control of bias current characteristics. This parameter adjustment mechanism achieves high manufacturing precision by compensating for process variations while using standard semiconductor fabrication processes

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If multiple bias current generators are implemented to provide both process-dependent and process-independent currents, then the adaptability is improved, but the device complexity increases

Engineering Contradiction:

ImproveadaptabilityVSAvoiddevice complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The bias current generators are designed to serve multiple functions: the first bias current generator provides process-dependent currents for peripheral circuits, while the second and third bias current generators provide process-independent currents for other blocks. This multi-functionality achieves high adaptability without requiring completely separate current generation systems for each function

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

Variable resistors with calibration codes enable dynamic adjustment of bias current characteristics based on process conditions. This dynamic calibration capability allows the system to adapt to different fabrication processes and environmental conditions while using a unified generator architecture, improving adaptability without proportionally increasing complexity

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS11733727B2Integrated circuit using bias current, bias current generating device, and operating method for the same

Publication Date: 2023.08.22 SAMSUNG ELECTRONICS CO LTD

AI summary

Disclosed is an integrated circuit including a first bias current generating circuit. The first bias current generating circuit includes a first amplifier receiving a reference voltage and a first voltage and amplifying a difference between them to output a first output voltage, a first bias current generator receiving the first output voltage and outputting a first bias current in response to the first output voltage, a variable resistor receiving the first bias current and outputting the first voltage in response to the first bias current and a calibration code, a second bias current generator receiving the first output voltage and outputting a second bias current to a peripheral circuit in response to the first output voltage, and a third bias current generator receiving the first output voltage and outputting a third bias current to an external device through a first pad in response to the first output voltage.