PMIC SMB Isolation for Memory Controller Power States

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Solution Overview

Problem

Existing memory sub-systems, such as SSDs, face challenges in managing system management bus (SMB) isolation during power transitions, leading to complications in accessing vital product data (VPD) and address resolution protocol (ARP) communications, particularly when the memory controller is powered down in low power states.

Innovation Solution

Integration of power management circuitry within a PMIC that buffers SMB signals to both a microcontroller and a memory controller, enabling automatic isolation and connection based on power states, thus ensuring seamless VPD and ARP communications regardless of power mode.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the memory controller is powered down in low power states, then power usage is reduced, but VPD and ARP communications cannot be accessed

Engineering Contradiction:
Improvepower usageVSAvoidVPD and ARP communication accessibility
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The SMB interface functionality is segmented between two controllers: the memory controller handles SMB communications during normal power states, while the microcontroller takes over SMB communications during low power states. This segmentation allows the system to maintain VPD and ARP communication accessibility regardless of which controller is active, resolving the contradiction between power savings and communication reliability.

Inventive Principle:
Principle #1Segmentation

2Reliability

If separate SMB isolation devices are used to disconnect the SMB from the memory controller in low power mode, then communication reliability is maintained, but device complexity increases

Engineering Contradiction:
ImproveSMB communication reliabilityVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the SMB isolation function with the PMIC by integrating the hot swap SMB controller directly into the power management circuitry. This consolidation eliminates the need for separate external isolation devices, reducing component count and system complexity while maintaining reliable SMB communication during power transitions between normal and low power states.

Inventive Principle:
Principle #5Merging (Combining)

3Volume of moving object

If power management circuitry and SMB routing are integrated into a single PMIC, then component size is reduced, but manufacturing complexity increases

Engineering Contradiction:
Improvecomponent sizeVSAvoidintegration complexity
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The PMIC is designed with multi-functionality, incorporating both power management capabilities and SMB routing functions within a single integrated circuit. The hot swap SMB controller embedded in the PMIC can dynamically route SMB communications to either the memory controller or microcontroller based on power state, providing universal functionality that reduces overall system size while managing manufacturing complexity through standardized integration processes.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4004688B1Power management integrated circuit based system management bus isolation
Publication Date: 2026.01.07 MICRON TECHNOLOGY INC
  • EP4004688B1 patent drawingFigure 1
  • EP4004688B1 patent drawingFigure 2
  • EP4004688B1 patent drawingFigure 3

AI summary

A power management integrated circuit (PMIC) is described for providing system management bus (SMB) isolation, along with memory sub-systems which include such a PMIC and methods of operating such devices. In one embodiment, a PMIC comprises a voltage supply input, power management circuitry, and elements of a SMB. The SMB elements can include an SMB input, an SMB hot swap controller coupled to the SMB input, one or more SMBs, and one or more SMB outputs. When integrated with a memory sub-system, one SMB output can be connected to a memory controller and another SMB output to a microcontroller. During different power states (e.g., normal or low power states), certain outputs can be isolated in order to manage communications on the SMB during the different power states of the memory sub-system using the PMIC.