Delta-Sigma Voltage Regulator Feedforward for Low-Ripple Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional voltage regulators, such as LDOs, face challenges including complex stability analysis, high ripple, poor bandwidth, and limited scalability and portability, especially at lower voltages, due to their analog and digital architectures.
Innovation Solution
A voltage regulator device incorporating a digital modulation device with a delta-sigma modulator, quantizer, and a feedforward path, which digitally modulates the feedback signal and feeds it forward to improve stability and reduce quantization noise, enabling efficient and reliable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional analog LDO architecture is used, then voltage regulation is achieved, but the stability analysis becomes complex due to varying pole and zero locations according to load current
Solution Approach 1:
The patent replaces the conventional analog error amplifier with a digital modulation device comprising a delta-sigma modulator and quantizer. This substitution transforms the continuous analog control signal into a pulsed digital signal, eliminating the need for complex stability analysis of analog feedback loops while maintaining effective voltage regulation through digital pulse-density modulation.
2Extent of automation
If conventional digital LDO architectures with ADC and shift register are used, then digital control is achieved, but the bandwidth becomes poor and ripple increases
Solution Approach 1:
The patent extracts and eliminates the shift register component from conventional digital LDO architectures. By directly connecting the quantizer output to the power device control input, the design removes the bandwidth-limiting element while maintaining digital control capabilities, thereby achieving both automated digital control and high regulation bandwidth.
3Use of energy by moving object
If class D LDO with PWM and filtering is used, then power efficiency is improved, but the design becomes process dependent and requires additional filtering components
Solution Approach 1:
The patent employs a delta-sigma modulator that generates a pulse-density modulated signal where the average pulse density directly represents the control value. This approach creates a natural digital-to-analog conversion through pulse averaging, eliminating the need for additional filtering stages while maintaining power efficiency through direct power device control.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
It is described a voltage regulator device (100), comprising: i) a power device (150), configured to receive an input signal (151) and to produce a corresponding output signal (152); ii) a comparator device (110), coupled via a feedback path (140) to the power device (150), and configured to receive the output signal (152) as a feedback signal (141), and to produce a compared feedback signal (112); and iii) a digital modulation device (120), arranged between the comparator device (110) and the power device (150), and configured to digitally modulate the compared feedback signal (112), and to provide the digitally modulated signal (121) to the power device (150), wherein the digital modulation device (120) comprises: iiia) a delta-sigma (122), iiib) a quantizer (124), and iiic) a feedforward path (128), configured to feedforward the compared feedback signal (112) beyond the delta-sigma (122).