Semiconductor Startup Circuit Reducing Reference Voltage Stabilization Time

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Solution Overview

Problem

Conventional reference voltage generating circuits with startup circuits take a long time to stabilize after power supply voltage is input, leading to prolonged startup times.

Innovation Solution

A semiconductor device with a startup circuit that outputs an initial voltage close to the stable equilibrium voltage of the reference voltage generating circuit, using a transistor and capacitor configuration to hold and instantly apply this voltage when power is input, reducing startup time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional startup circuit is connected to a reference voltage generating circuit, then the circuit can be started up when power is input, but it takes a significantly long time for the circuit to reach a stable equilibrium state

Engineering Contradiction:
Improvestartup capabilityVSAvoidstartup time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-charging a capacitor with the stable reference voltage before power-down, and then instantly discharging it to the input node upon power-up. This preliminary storage of the correct voltage state eliminates the long startup time by providing an immediate voltage kick-start to the reference voltage generating circuit, while still ensuring reliable startup operation.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If power supply voltage is simply input to a reference voltage generating circuit at the time of startup, then the circuit structure remains simple, but the reference voltage generating circuit is not started up properly or takes a long time to stabilize

Engineering Contradiction:
Improvecircuit structureVSAvoidstartup reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements preliminary action by pre-charging a capacitor with the stable reference voltage before power-down occurs. When power is restored, this pre-charged capacitor instantly discharges to provide the necessary initial voltage to the input node, ensuring reliable startup without requiring complex additional circuitry. This approach maintains circuit simplicity while dramatically improving startup reliability.

Inventive Principle:
Principle #10Preliminary action

3Stability of the object's composition

If the reference voltage generating circuit operates continuously to maintain stable voltage, then the output remains stable, but power consumption increases

Engineering Contradiction:
Improveoutput voltage stabilityVSAvoidpower consumption
Core Design Contradiction:
Stability of the object's compositionVSUse of energy by moving object

Solution Approach 1:

The patent applies periodic action by enabling the reference voltage generating circuit only when needed - specifically, it uses a control signal to activate the circuit during startup and when power is restored, rather than keeping it continuously operating. The pre-charged capacitor maintains the voltage during power-down periods, allowing the main circuit to remain inactive and consume minimal power while still providing stable output when required.

Inventive Principle:
Principle #19Periodic action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The configuration significantly shortens the time for the reference voltage generating circuit to reach a stable equilibrium state, allowing for quick startup and reducing power consumption by controlling power supply.

Implementation Method 1

a first electrode of the transistor 111 is electrically connected to a first electrode of a capacitor 113

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP2431833B1Semiconductor device
Publication Date: 2019.11.13 SEMICON ENERGY LAB CO LTD
  • EP2431833B1 patent drawingFigure 1
  • EP2431833B1 patent drawingFigure 2
  • EP2431833B1 patent drawingFigure 3

AI summary

Provided is a startup circuit which allows a reference voltage generating circuit to start up and reach a stable equilibrium state in an extremely short period. The startup circuit is configured to hold voltage which is substantially the same as internal voltage of the reference voltage generating circuit in the stable equilibrium state even when power is not supplied to the startup circuit. The voltage is output from the startup circuit to the reference voltage generation circuit when the reference voltage generating circuit is started.