Cascaded Current Cells for Low-Noise Ramped Current Generation
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Solution Overview
Problem
Existing methods for generating a ramped current signal in regenerative receivers are limited by noise and reduced linearity, especially at low supply voltages, and require additional components for measuring start-up time, which are not cost-effective and lack precision.
Innovation Solution
An electronic circuit with a cascade of current cells, each with a trigger input and output, generates a ramped current signal by sequentially activating current sources, allowing for controlled current ramping and precise timing, using a logic unit to manage activation and deactivation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a voltage-to-current converter is used to generate ramped current signal, then the current signal can be generated, but noise increases and linearity deteriorates, especially at low supply voltages
Solution Approach 1:
The patent replaces the voltage-to-current converter (analog/electrical conversion system) with a direct current source array controlled by digital logic circuits. Instead of converting voltage to current through an analog converter, the system uses multiple current sources (I1, I2, I3, I4) that are directly controlled by logic units (LU1, LU2, LU3, LU4) based on digital control signals. This substitution eliminates the noise and linearity issues inherent in analog voltage-to-current converters.
2Measurement precision
If additional components are added for measuring start-up time, then start-up time measurement is enabled, but device complexity and manufacturing cost increase
Solution Approach 1:
The logic units (LU1, LU2, LU3, LU4) serve dual functions: they control the switching of current sources to generate the ramped current signal, and simultaneously measure the start-up time by detecting when the oscillation condition is met. The same logic units that manage current source activation also monitor the oscillation detector output, eliminating the need for separate time measurement components and reducing overall device complexity.
3Reliability
If a voltage ramp is converted to current, then current signal is generated, but the system size increases and manufacturing cost rises
Solution Approach 1:
The patent divides the current generation function into multiple discrete current sources (I1, I2, I3, I4), each controlled by its own logic unit. This segmentation allows for modular design and integration, where each current source and its controlling logic unit can be independently optimized and manufactured. The segmented architecture reduces overall system complexity and manufacturing cost compared to a single integrated voltage-to-current converter, while maintaining reliable current signal generation.
Data Source
AI summary
An electronic circuit (10) configured to generate a ramped current signal for a receiver circuit (30), includes a first current cell (20) including a first current source (55), a trigger input (25) to activate the first current source (55) and a trigger output (26); a second current cell (21) including a second current source (55′), a trigger input (25) to activate the second current source (55′) and a trigger output (26), wherein the trigger output (26) of the first current cell (20) is connected to the trigger input (25) of the second current cell (21); and a current supply (24) connected to an input of the receiver circuit (30) and selectively connectable with any of the first current source (55) and the second current source (55′).