Digitally Controlled LDO Regulator Without Auto-Zero Dead Band
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Digitally controlled low dropout regulators face challenges in controlling output voltage during the auto-zero processing period, as the AD converter enters a dead-band state and is unable to respond to changes in output voltage, leading to instability and false determinations.
Innovation Solution
A digitally controlled low dropout regulator is designed with multiple AD converters and an impedance variable circuit, where one AD converter operates while another performs auto-zero processing, allowing continuous voltage control by alternately switching between auto-zero and normal operation periods, and utilizing a pulse generating circuit to manage the auto-zero process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If auto-zero processing is performed by the AD converter, then measurement precision is improved, but the AD converter enters a dead-band state and cannot respond to output voltage changes
Solution Approach 1:
The patent divides the AD converter into two operational modes: auto-zero processing mode for calibration and normal conversion mode for voltage measurement. By segmenting the operational states and switching between them, the system achieves both high measurement precision during calibration and rapid response during normal operation, resolving the contradiction between precision and speed.
2Device complexity
If a single AD converter is used for both auto-zero processing and voltage control, then device complexity is reduced, but control reliability deteriorates during auto-zero period
Solution Approach 1:
The patent implements dynamic switching between auto-zero processing and normal voltage control operations within a single AD converter. By dynamically adjusting the converter's operational state based on timing signals, the system maintains control reliability during the auto-zero period while keeping device complexity low through reuse of the same hardware component.
3Measurement precision
If auto-zero processing is performed continuously, then measurement precision is maintained, but productivity decreases due to dead-band periods
Solution Approach 1:
The patent implements periodic auto-zero processing at predetermined intervals rather than continuous processing. This periodic approach maintains measurement precision through regular calibration while minimizing the impact on productivity by limiting dead-band periods to brief, scheduled intervals, allowing normal voltage control to proceed efficiently between calibrations.
Data Source
AI summary
To provide a digitally controlled LDO regulator that can control an output voltage even during an auto-zero processing period. A digitally controlled low dropout regulator is provided that includes a plurality of AD converters and an impedance variable circuit, each of the plurality of AD converters including a comparator, in which a first signal from each of the plurality of AD converters is input to the impedance variable circuit; a second signal output from the impedance variable circuit is input to one of two terminals of each of the plurality of AD converters; when one of the plurality of AD converters is in operation, another of the plurality of AD converters performs auto-zero processing to set a voltage value used as a reference; and the comparator compares a voltage value of the second signal input to the one of the two terminals with the set voltage value.