Resistor Configuration Circuit With Digital Current Code Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing configuration circuits for determining digital codes in integrated circuits face limitations in resolution and accuracy due to the dependence of test voltage and reference voltage on current mirror circuits, leading to restricted representation of unique digital codes.
Innovation Solution
A configuration circuit using a digitally controlled current source that generates output current based on multibit control words, with a voltage comparison circuit comparing the test voltage to an independent reference voltage to obtain digital codes, eliminating the need for ADC circuitry and reducing complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a current mirror circuit is used to develop test voltage and reference voltage, then the circuit can operate with simple components, but the test voltage and reference voltage vary dependently which limits measurement precision
Solution Approach 1:
The patent segments the voltage generation functions by using a digitally controlled current source to generate test voltage independently from the reference voltage. This separation allows the test voltage to be precisely controlled through digital codes while the reference voltage remains stable and independent, resolving the dependency issue caused by current mirror circuits.
Solution Approach 2:
The patent replaces the analog current mirror circuit mechanism with a digitally controlled current source. This substitution enables precise digital control of the test current, allowing for accurate resistance measurement through digital codes while eliminating the analog dependency inherent in current mirror circuits.
2Device complexity
If a fixed current source is used to develop test voltage, then the circuit simplicity is maintained, but the number of unique digital codes that can be represented is limited by resolution and accuracy
Solution Approach 1:
The patent implements a dynamically controllable current source that can adjust its output based on multibit control words. This dynamic control allows the system to generate multiple unique digital codes by varying the current levels precisely, overcoming the limitation of fixed current sources while maintaining circuit simplicity through digital control.
Solution Approach 2:
The patent changes the current parameter dynamically using digitally controlled current sources that respond to multibit control words. By varying the current magnitude according to digital inputs, the system can represent multiple unique digital codes, expanding the measurement range and resolution without increasing circuit complexity.
3Measurement precision
If an ADC is used to create digital representation of analog signal, then digital code accuracy is improved, but the circuit complexity and cost increase
Solution Approach 1:
The patent extracts the analog-to-digital conversion function by using a digitally controlled current source that directly generates digital codes based on resistance measurements. This approach eliminates the need for separate ADC circuitry while maintaining measurement accuracy, as the digital control words directly represent the measured resistance values.
Solution Approach 2:
The patent uses a digitally controlled current source that creates a digital representation of the resistance measurement directly, copying the essential function of an ADC without requiring actual ADC hardware. The multibit control words serve as digital copies of the analog resistance values, achieving the same result with simpler circuitry.
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
This approach allows for the determination of 64 unique digital codes with improved accuracy and reduced circuit complexity, while being immune to noise and stability issues, and can handle multiple resistors with minimal calibration.
Implementation Method 1
a test voltage develops in response to the output current
Data Source
AI summary
A configuration circuit for obtaining a digital code includes a controller circuit that generates a plurality of multibit control words. A digitally controlled current source circuit receives a multibit control word generated by the controller circuit. The digitally controlled current source circuit generates an output current that corresponds to the multibit control word in accordance with a predetermined output curve. A test voltage node receives the output current, and a test voltage develops in response to the output current. A reference voltage node develops a reference voltage, the level of which is independent of the multibit control word. A voltage comparison circuit (i) receives the test voltage and the reference voltage, (ii) compares the two voltages to produce a comparison result and (iii) sends the comparison result to the controller circuit. The digital code is obtained by the configuration circuit using the comparison result and the multibit control word.