Power Switch Circuit for Fast Startup With Lower Rush Current

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Solution Overview

Problem

Existing semiconductor integrated circuits face challenges in efficiently reducing power consumption while minimizing the overhead of switching between on and off states, which can lead to malfunctions due to excessive rush currents and IR drops.

Innovation Solution

The implementation of a power switch circuit with a combination of slew-rate control and time-sharing control switch blocks, where the slew-rate control switch block gradually increases internal voltage to prevent rush currents, and the time-sharing control switch block rapidly increases voltage to shorten startup time, allowing for efficient power supply and shutdown of circuit blocks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a switch circuit is used to shut down power to circuit blocks, then power consumption is reduced, but excessive rush currents and IR drops occur during switching

Engineering Contradiction:
Improvepower consumptionVSAvoidrush currents and IR drops
Core Design Contradiction:
Loss of energyVSObject-affected harmful factors

Solution Approach 1:

The switch circuit is divided into multiple switch sections (first switch section, second switch section, etc.) that are controlled independently. This segmentation allows gradual connection of circuit blocks to power supply lines, preventing sudden rush currents while enabling effective power shutdown when not needed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The switch circuit dynamically adjusts its switching behavior based on operational requirements. During startup, switch sections are activated in a controlled sequence to gradually increase voltage and prevent rush currents. During shutdown, the circuit effectively disconnects power to reduce consumption, adapting its behavior to different operational states.

Inventive Principle:
Principle #15Dynamics

2Loss of time

If switch sections are activated simultaneously, then startup time is reduced, but excessive rush currents occur

Engineering Contradiction:
Improvestartup timeVSAvoidrush currents
Core Design Contradiction:
Loss of timeVSObject-affected harmful factors

Solution Approach 1:

The switch sections are activated in periodic sequences rather than simultaneously. The control circuit activates switch sections in groups or individually at different times, creating a staged startup process that limits rush currents while maintaining relatively fast overall startup performance.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

Before full power activation, the switch circuit performs preliminary actions by gradually connecting switch sections to power supply lines. This preliminary staged activation prevents excessive rush currents from occurring when the entire circuit block is powered on simultaneously, while still achieving quick startup through efficient sequencing.

Inventive Principle:
Principle #10Preliminary action

3Loss of energy

If switch sections are activated sequentially to prevent rush currents, then startup time increases, but power consumption during switching is reduced

Engineering Contradiction:
Improvepower consumption during switchingVSAvoidstartup time
Core Design Contradiction:
Loss of energyVSLoss of time

Solution Approach 1:

The circuit changes operational parameters during the startup process. Switch sections are activated with controlled timing and voltage ramping, adjusting the rate of power application to balance between minimizing rush currents and maintaining acceptable startup speed. The activation sequence and voltage levels are optimized to reduce energy loss during transitions.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3046258B1Semiconductor device
Publication Date: 2020.06.03 KK TOSHIBA
  • EP3046258B1 patent drawingFigure 1
  • EP3046258B1 patent drawingFigure 2
  • EP3046258B1 patent drawingFigure 3~4

AI summary

According to one embodiment, a semiconductor device includes: a voltage line to which a first voltage is applied; a first circuit configured to operate by using the first voltage; and a second circuit configured to control a connection between the voltage line and the first circuit. The second circuit includes: at least one first switch circuit configured to connect the first circuit and the voltage line based on a first control signal; and a second switch circuit including a plurality of switch sections configured to connect the first circuit and the voltage line based on a plurality of second control signals different from the first control signal.