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Industrial Research And Consultancy Centre
Patent
A Wide-Range Square-Wave Current Excitation Module with Noise Cancellation
Abstract

This invention introduces a highly efficient current generator designed to produce precise square wave currents across a wide range, from nanoamps to microamps, with minimal noise and improved accuracy. By employing a single floating current source, it effectively cancels out noise and mismatches that typically arise from multiple sources, ensuring reliable measurements. The system mitigates errors caused by parasitic capacitances, maintaining linearity over a broad range of resistances and expanding its applicability to capacitive sensing applications through parameter adjustments.

Problem Statement

Current generators used to produce precise square wave currents across a wide range, from very low to higher levels (such as from nanoamps to microamps), often face efficiency challenges. Traditional methods require large transistor sizes, making them inefficient and bulky. This inefficiency arises because the ratio between the smallest and largest transistor sizes needed can be extremely high, leading to wasted space and energy. Moreover, these generators can suffer from noise interference, affecting their accuracy. There is a critical need for a more efficient and compact solution that can generate precise square wave currents over a wide range while effectively canceling out noise, ensuring reliable performance across various applications in fields like healthcare, agriculture, and industrial monitoring.

Uniqueness of the Solution
  • Single Current Source: This innovation utilizes a single floating current source to eliminate noise and mismatches associated with multiple current sources. 
  • Efficient Noise Cancellation: It enables noise cancellation directly at the output currents (I1 and I2), ensuring high accuracy. 
  • Precise Measurement: It minimizes errors from parasitic capacitances, significantly enhancing measurement precision. 
  • Enhanced Measurement Capabilities: It achieves linear output over a broad range of resistances, expanding measurement capabilities. 
  • Parameter Tuning: It is adaptable for capacitive sensing applications through parameter tuning, enhancing versatility.
Prototype Details

An early prototype has been developed and demonstrated.

Current Status of Technology

The test chip and test board are fabricated; measurements have been performed in a lab environment. 

Technology readiness level

5

Societal Impact

This innovation enhances reliability of electronic devices in various sectors by improving measurement accuracy and reducing noise interference. It facilitates advancements in sensor technology, benefiting fields such as healthcare, agriculture, and industrial automation with more precise monitoring capabilities.

Applications or Domain

This technology enables improvement in accuracy and reliability in sensor systems across industries. 

  • Healthcare: Medical diagnostics and wearable health monitoring devices - enables precise current generation for sensor calibration in medical devices and electronic instrumentation
  • Electronics Manufacturing: Precision instrumentation and test equipment
  • Aerospace and Defense: Sensor systems and instrumentation
  • Automotive: Vehicle diagnostics and sensor technology
  • Environmental Monitoring: Weather stations and climate sensors

Geography of IP

Type of IP

Application Number

202021034834

Filing Date
Grant Number

515187

Grant Date
Assignee(s)
Indian Institute of Technology Bombay
**This IP is owned by IIT Bombay**