AC-Sampled LDO Suppression Circuit Without Added DC Power
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrated circuits, particularly low dropout regulators, face challenges in effectively suppressing power supply noise, especially in applications like video surveillance and communication systems, where noise suppression requirements are high and tend to deteriorate at increasing frequencies.
Innovation Solution
A power supply suppression circuit comprising a sampling unit, a compensation unit, and an amplification unit is introduced, which samples an AC signal from a preset node position of a low dropout regulator, calculates differences, and generates an enhanced signal in phase with the power supply voltage to ensure the input end voltage of the power output stage closely follows the power supply voltage, thereby suppressing noise within a target frequency band without additional DC power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional low dropout regulator is used, then the circuit achieves basic voltage regulation, but the power supply noise suppression capability deteriorates at increasing frequencies
Solution Approach 1:
The power supply suppression circuit is segmented into three functional units: a sampling unit that samples AC signals from the power supply, a compensation unit that processes the sampled signal, and an amplification unit that amplifies the compensated signal. This segmentation allows each unit to be optimized independently for its specific function while working together to suppress power supply noise across different frequency ranges.
Solution Approach 2:
The compensation unit acts as an intermediary between the sampling unit and the amplification unit. It receives the sampled AC signal, processes it through compensation mechanisms, and passes the compensated signal to the amplification unit. This intermediary role allows for signal conditioning and optimization before final amplification, improving overall noise suppression effectiveness.
2Reliability
If additional noise suppression circuits are added to improve suppression effect, then the power supply noise suppression capability is improved, but the DC power consumption increases
Solution Approach 1:
The circuit focuses on suppressing periodic AC noise signals rather than continuously consuming power for DC regulation. The sampling unit captures AC components at specific moments, the compensation unit processes these periodic signals, and the amplification unit amplifies only when needed. This periodic action approach reduces continuous DC power consumption while maintaining effective noise suppression.
Solution Approach 2:
The amplification unit amplifies the compensated AC signal to a degree that is sufficient for noise suppression purposes, rather than continuously maintaining maximum amplification. This partial action approach provides adequate noise suppression effectiveness while avoiding excessive power consumption that would result from continuous full-power operation.
Data Source
AI summary
A power supply suppression circuit (10), a chip and a communication terminal that only achieve the enhancement of the power supply suppression capability from an AC, without generating additional circuit power consumption. The power supply suppression circuit (10) comprises a sampling unit (105), a compensation unit (106), and an amplification unit (107). The sampling unit (105) is connected to the compensation unit (106), and the compensation unit (106) is connected to the amplification unit (107). The power supply suppression circuit (10) obtains an AC signal from a preset sampling node position of a low dropout regulator, and generates an enhancement signal in phase with the AC signal on a power supply (Vdd) on the basis of the AC signal, such that the input end voltage of the power output stage of the low dropout regulator immediately follows the voltage change of the power supply (Vdd).