VCO Power Supply Stabilization Without Op-Amp Noise
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Voltage control oscillators in PLL and CDR circuits face issues with signal jitter due to noise, and existing low dropout regulator circuits result in large area, high power dissipation, and insufficient headroom, with operational amplifier noise affecting performance.
Innovation Solution
A power supply stabilizing circuit using a current-adjusting N-type transistor and an adjusting voltage generation circuit, where the transistor operates in a saturation region to minimize current variation, generating a stable power signal for the voltage control oscillator, with a filter circuit to stabilize the adjusting voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a low dropout regulator (LDO) circuit with operational amplifier feedback mechanism is used to stabilize voltage, then voltage stabilizing function is achieved, but circuit area becomes large and power dissipation increases
Solution Approach 1:
The patent extracts and removes the operational amplifier feedback mechanism from the voltage stabilizing circuit, replacing it with a simplified transistor-based current adjustment circuit. This extraction eliminates the large-area operational amplifier while retaining the essential voltage stabilizing function through direct transistor control, thereby resolving the contradiction between achieving voltage stabilization and minimizing circuit area.
Solution Approach 2:
The patent replaces the complex, power-intensive operational amplifier with a simple transistor structure that consumes minimal power and occupies minimal area. The transistor-based solution acts as a lightweight alternative that achieves the same stabilizing function without the overhead of the operational amplifier, effectively reducing both area and power dissipation.
2Reliability
If a low dropout regulator (LDO) circuit with operational amplifier feedback mechanism is used to stabilize voltage, then voltage stabilizing function is achieved, but power dissipation becomes large
Solution Approach 1:
The patent removes the operational amplifier from the feedback mechanism, eliminating its associated power consumption. The resulting transistor-based circuit achieves voltage stabilization with minimal power dissipation, directly resolving the contradiction between maintaining voltage stability and reducing power usage.
Solution Approach 2:
The operational amplifier is replaced with a power-efficient transistor structure that consumes minimal energy while performing the same voltage stabilizing function. This substitution dramatically reduces power dissipation while maintaining the essential stabilizing capability.
3Reliability
If operational amplifier feedback mechanism is used for filtering activity, then voltage filtering is achieved, but noise from operational amplifier affects voltage control oscillator performance
Solution Approach 1:
The patent extracts the operational amplifier from the filtering mechanism and replaces it with a transistor-based filtering circuit. This elimination removes the noise source inherent to operational amplifiers while preserving the voltage filtering function, thereby resolving the contradiction between achieving filtering and avoiding amplifier noise interference.
Solution Approach 2:
The noisy operational amplifier is replaced with a quiet transistor-based filtering circuit that performs the same voltage filtering function without introducing operational amplifier noise. This substitution eliminates the harmful noise factor while maintaining the essential filtering capability.
4Productivity
If manufacturing process progresses to smaller dimensions, then integration density increases, but headroom becomes insufficient for voltage withstanding
Solution Approach 1:
The patent changes the operating parameters of the transistor circuit to optimize for small-dimensional manufacturing processes. By adjusting the transistor biasing and operating point, the circuit achieves adequate voltage withstanding capability despite the reduced headroom inherent in scaled manufacturing, thereby resolving the contradiction between integration density and voltage withstanding strength.
Data Source
AI summary
The present invention discloses a power supply stabilizing circuit having noise suppressing mechanism configured to drive a voltage-control oscillating circuit that includes a current-adjusting N-type transistor including a drain, a source and a gate and an adjusting voltage generation circuit. The drain receives a first operation voltage. The source generates a power signal to the voltage control oscillator circuit. The gate receives an adjusting voltage. The adjusting voltage generation circuit operates according to a second operation voltage higher than the first operation voltage and receives a reference voltage that is a division of the first operation voltage to generate the adjusting voltage. The adjusting voltage is a sum of the reference voltage and a threshold voltage of the current-adjusting N-type transistor such that the current-adjusting N-type transistor operates in a saturation region to keep a current variation amount of the power signal smaller than a predetermined value.