Power Control Semiconductor Device with Merged Control Terminal

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional series regulators require multiple external terminals for stepwise voltage control and on/off functionality, increasing chip size and cost, especially when using microcomputers without built-in digital-analog converters.

Innovation Solution

A power control semiconductor device with a voltage control transistor, control circuit, bias circuit, and logic circuit that uses a voltage divider and error amplifier to change output voltage stepwise with few external terminals, allowing microcomputers without digital-analog converters to control the device, and includes a logic circuit to stop the bias circuit operation without additional external terminals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple external terminals are provided for control input, then stepwise voltage control and on/off functionality are achieved, but chip size and package size increase

Engineering Contradiction:

Improvevoltage control functionalityVSAvoidchip size

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent merges the on/off control signal input terminal with the control voltage input terminal into a single terminal. The control circuit internally separates these functions based on the voltage level detected, eliminating the need for separate terminals while maintaining both on/off control and stepwise voltage control capabilities

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The single control input terminal serves multiple functions: it accepts both on/off control signals (through voltage divider detection) and control voltages for stepwise voltage adjustment (through error amplifier detection). This multi-functional terminal reduces the total number of external terminals required

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Use of energy by moving object

If separate terminals are provided for on/off control signal, then power consumption is reduced through standby mode, but the number of external terminals increases

Engineering Contradiction:

Improvestandby current consumptionVSAvoidchip size

Core Design Contradiction:

Use of energy by moving objectVSArea of stationary object

Solution Approach 1:

The on/off control signal input function is merged into the existing control voltage input terminal. The control circuit uses internal voltage division to detect when the control voltage falls within a specific range (indicating an on/off signal) versus when it represents a stepwise adjustment command, thereby achieving standby power control without adding terminals

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The control circuit automatically distinguishes between on/off control signals and voltage adjustment commands based on the voltage level at the shared terminal, without requiring external circuitry or additional signal processing components. The internal voltage divider and comparator circuits self-service the dual-function requirement

Inventive Principle:

Principle #25Self-service

3Measurement precision

If microcomputer with digital-analog converter is used for voltage control, then precise voltage control is achieved, but cost increases

Engineering Contradiction:

Improvevoltage control precisionVSAvoidcost

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent replaces the need for a digital-analog converter (DAC) in the microcomputer with a purely electronic control circuit implementation. The control circuit uses voltage division, error amplification, and transistor switching to achieve precise voltage control directly from digital control signals, eliminating the requirement for expensive DAC hardware in the microcomputer

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The control circuit acts as an intermediary between the microcomputer and the power control transistor. It translates simple digital control signals into precise analog voltage control through internal voltage division and error amplification, allowing the use of low-cost microcomputers without DAC while maintaining precise voltage control

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11454998B2Power control semiconductor device and variable output voltage power supply

Publication Date: 2022.09.27 MITSUMI ELECTRIC CO LTD

AI summary

A power control semiconductor device includes a voltage control transistor, a control circuit, a bias circuit, and external terminals. The voltage control transistor is connected between a voltage input terminal and an output terminal. The bias circuit generates a voltage that operates the control circuit. Output control signals provided from an outside are input to the external terminals to control an output voltage. The control circuit includes an error amplifier and a logic circuit. The error amplifier outputs a voltage corresponding to a potential difference between a reference voltage and a voltage divided by a voltage divider that divides the output voltage. The logic circuit generates: a signal that changes the divided voltage in accordance with the output control signals; and a signal that stops operation of the bias circuit in response to a combination of the output control signals.