Voltage Regulator Compensation Network for Higher PSR Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Voltage regulators face challenges in maintaining accuracy and stability due to component mismatch, finite gain of error amplifiers, and external noise, leading to dynamic variations in output voltage, which affect power supply rejection (PSR).
Innovation Solution
A voltage regulator design incorporating a first and second amplifier with a current mirror and a compensation network using passive and active components to reduce variations caused by parasitic capacitance and supply voltage fluctuations, improving PSR by mimicking a component network between the transistor's current terminal and gate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a voltage regulator uses a feedback-loop based regulator with error amplifier, then voltage regulation function is achieved, but finite gain of the error amplifier causes voltage accuracy degradation
Solution Approach 1:
The patent introduces a compensation network as an intermediary element that senses the output voltage and generates a compensating signal to counteract the effects of finite error amplifier gain. This compensation network acts as a mediator between the error amplifier and the output, improving voltage accuracy without requiring the error amplifier to have infinite gain.
Solution Approach 2:
The compensation network creates a copied or replicated version of the output voltage signal and uses it to generate compensation current that counteracts the voltage errors. By copying the output signal and processing it through the compensation network, the system can correct accuracy errors without changing the core error amplifier structure.
2Device complexity
If a voltage regulator is designed with simple structure, then device complexity is reduced, but power supply rejection capability deteriorates due to susceptibility to supply voltage disturbances
Solution Approach 1:
The compensation network serves as an intermediary that intercepts supply voltage disturbances before they can significantly affect the output. By placing this network in the feedback path, it mediates between the supply voltage variations and the output voltage, reducing the impact of supply disturbances while maintaining a relatively simple overall structure.
Solution Approach 2:
The patent enhances the feedback mechanism by adding the compensation network to the existing feedback loop. This extended feedback path continuously monitors the output voltage and adjusts the compensation current in real-time to counteract supply voltage variations, improving power supply rejection through enhanced feedback control.
3Measurement precision
If a voltage regulator operates with high precision requirements, then voltage accuracy is improved, but sensitivity to parasitic capacitance and component mismatch increases
Solution Approach 1:
The compensation network converts the harmful effect of parasitic capacitance into a beneficial compensation mechanism. By sensing the voltage errors caused by parasitic capacitance and component mismatch, the network generates compensating currents that counteract these harmful effects, effectively turning the problem into a solution.
Solution Approach 2:
The compensation network dynamically adjusts electrical parameters (current and voltage) to counteract the effects of parasitic capacitance. By changing the compensation current parameter in response to detected voltage errors, the system maintains high output voltage accuracy despite the presence of parasitic elements.
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
The compensation network effectively reduces output current and voltage variations, enhancing the power supply rejection ratio (PSR) and stabilizing the output voltage, thereby improving the regulator's resistance to supply disturbances.
Implementation Method 1
the transistor has a parasitic capacitance between the second current terminal and the gate
Implementation Method 2
The compensation network can improve the power supply rejection (PSR) of the voltage regulator by reducing variations in voltage/current at the output of the voltage regulator associated with variations in the supply voltage
Data Source
AI summary
A voltage regulator and method. The voltage regulator includes a first amplifier having: a first input couplable to a reference voltage; a second input coupled to a feedback path; a current mirror; first and second branches coupled to an input and output of the current mirror. A node of the second branch forms an output of the first amplifier. The voltage regulator includes a second amplifier comprising a transistor having: a first terminal couplable to a supply voltage; a gate coupled to the output of the first amplifier; and a second terminal coupled to an output of the voltage regulator. The feedback path is coupled to the output of the voltage regulator. The voltage regulator includes a compensation network having at least one passive component to reduce variations in an output current of the voltage regulator caused by the parasitic capacitance of the transistor and variations in the supply voltage.