All-Digital Distributed LDO Architecture for Fast Droop Response
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional distributed LDO architectures face scalability issues due to custom communication requirements and analog voltage generation, leading to inefficiencies in voltage regulation and transient response across large IP blocks.
Innovation Solution
A distributed and scalable all-digital LDO (D-DLDO) architecture that uses all-digital standard cells, eliminating the need for global/inter-LDO communication and analog voltage routing, with an all-digital PID controller and on-die voltage monitors for fast droop detection and mitigation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional distributed LDO architecture with analog voltage generation and custom communication is used, then voltage regulation can be achieved, but device complexity and scalability are worsened
Solution Approach 1:
The patent replaces analog voltage generation and communication mechanisms with all-digital circuits. Specifically, analog voltage monitors are substituted with digital voltage sensors that output digital codes, and custom analog communication interfaces are replaced with standard digital communication protocols, eliminating the need for specialized analog routing and reducing device complexity while maintaining voltage regulation functionality
Solution Approach 2:
The patent changes the operating domain from analog to digital by converting voltage signals into digital codes through ADC (analog-to-digital conversion). This parameter transformation allows the system to operate entirely in the digital domain, where voltage regulation control signals and communication are both digital, thereby simplifying the overall architecture and improving scalability across different technology nodes
2Device complexity
If single point voltage regulator is used, then device complexity is reduced, but transient response and voltage regulation effectiveness are worsened due to large local IR drop
Solution Approach 1:
The patent divides the single point voltage regulator into multiple distributed LDO units spread across the IP block. Each LDO unit independently regulates voltage in its local region, reducing the impact of large local IR drops. The segmentation allows parallel operation of multiple regulators, improving transient response effectiveness while maintaining overall system simplicity through standardized modular units
3Reliability
If voltage guard-band is increased to compensate for transient droop, then transient response reliability is improved, but energy efficiency is worsened
Solution Approach 1:
The patent implements fast digital feedback mechanisms where digital voltage monitors continuously monitor the output voltage and immediately detect droop conditions. The digital control logic processes this feedback and adjusts the control signals to power gates in real-time, enabling rapid compensation for transient droop without requiring excessive voltage guard-band, thus maintaining energy efficiency while ensuring transient response reliability
Data Source
AI summary
A distributed and scalable all-digital LDO (D-DLDO) voltage regulator allowing rapid scaling across technology nodes. The distributed DLDO includes many tillable DLDO units regulating a single supply voltage with a shared power distribution network (PDN). The D-DLDO includes an all-digital proportional-integral-derivative (PID) controller that receives a first code indicative of a voltage behavior on a power supply rail. A droop detector is provided to compare the first code with a threshold to determine a droop event, wherein information about the droop event is provided to the PID controller, wherein the PID controller generates a second code according to the first code and the information about the droop event. The DLDO includes a plurality of power gates that receive the second code.