Current Generating Circuit Using Charge Adjusting Paths
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Solution Overview
Problem
Conventional charge pumping circuits face a narrow head room issue due to limited control voltage range, which affects transistor operation and introduces noise, making it unsuitable for various circuit applications.
Innovation Solution
A current generating circuit utilizing charge adjusting paths and capacitors to generate a target current based on voltage differences, allowing for a wider operational range and reducing noise by substituting conventional current sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional current sources are used in charge pumping circuits, then the circuit can provide necessary current, but noise is generated and head room is limited
Solution Approach 1:
The patent extracts the noise-generating function from the conventional current source and separates it into two independent components: a noise-free reference current source and a programmable current mirror circuit. This extraction eliminates the noise problem while preserving the current provision function, and the modular structure enables flexible adaptation to different current requirements without the narrow head room constraint.
Solution Approach 2:
The patent introduces a programmable current mirror circuit as an intermediary between the reference current source and the load. This intermediary component allows precise control of output current through digital programming while maintaining electrical isolation and noise immunity, thereby solving both the noise and adaptability issues simultaneously.
2Object-affected harmful factors
If overdrive voltage is increased to reduce noise from current sources, then noise is reduced, but the narrow head room issue worsens
Solution Approach 1:
The patent extracts the noise-generating mechanism from the current source operation and relocates it to a controlled environment where large overdrive voltages are not needed. By using a programmable current mirror with digital control, the system achieves low noise without requiring increased overdrive voltage, thus avoiding the head room problem.
Solution Approach 2:
The patent replaces the conventional analog current source mechanism (which relies on voltage head room and overdrive) with a digitally-controlled current mirror system. This substitution eliminates the need for large overdrive voltages while maintaining noise performance, as the digital control provides precise current regulation without the electrical head room constraints of analog circuits.
Data Source
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AI summary
A current generating circuit (200), which comprises: a first capacitor (C_1), comprising a first terminal and a second terminal; a second capacitor (C_2), comprising a first terminal and a second terminal; a first charge adjusting path (CP_1), arranged for adjusting charges of the first capacitor according to a first charge adjusting voltage (V_1); a second charge adjusting path (CP_2), arranged for adjusting charges of the second capacitor (C_2) according to the first charge adjusting voltage; and a current generating path (201), coupled to the first capacitor and the second capacitor, arranged for generating a target current (I_T) based on a difference between a first voltage (V_1) provided by the first capacitor (C_1) and a second voltage (V_2) provided by the second capacitor (C_2).