Reference Voltage Generator Circuit for Low-Power Mode Accuracy

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Solution Overview

Problem

Microcontrollers face challenges in balancing the need for accurate reference voltage generation in normal operating modes while minimizing electric consumption in low-consumption modes, often requiring multiple reference voltage generator circuits that are complex, costly, and occupy significant space.

Innovation Solution

A single reference voltage generator circuit utilizing a diode-configured transistors, variable resistors, and a control unit to adapt current injection based on operating mode, reducing the impact of offset voltage and electric consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single reference voltage generator circuit is used for both normal and low-consumption modes, then device complexity is reduced, but it becomes difficult to simultaneously achieve accurate reference voltage in normal mode and minimize consumption in low-consumption mode

Engineering Contradiction:

Improvenumber of reference voltage generator circuitsVSAvoidaccuracy of reference voltage

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements dynamic adaptability by enabling the single reference voltage generator circuit to switch between different operating configurations. The circuit can dynamically adjust its operation mode depending on whether the microcontroller is in normal or low-consumption mode, allowing it to optimize between accuracy and power consumption rather than being fixed in one configuration

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes operational parameters of the reference voltage generator circuit to accommodate different modes. By adjusting parameters such as current injection levels and operational duty cycles, the circuit maintains accurate reference voltage generation in normal mode while reducing power consumption in low-consumption mode

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If the reference voltage generator circuit operates continuously with high accuracy in normal mode, then measurement precision is improved, but use of energy increases during low-consumption mode

Engineering Contradiction:

Improveaccuracy of reference voltageVSAvoidelectric consumption of reference voltage generator circuit

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies periodic action by operating the reference voltage generator circuit with different duty cycles depending on the mode. In low-consumption mode, the circuit operates intermittently rather than continuously, reducing energy consumption while still providing necessary reference voltage functionality. In normal mode, it operates continuously with higher accuracy

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent implements partial action by providing just enough reference voltage accuracy for low-consumption mode operations without the full accuracy level required in normal mode. This partial operation reduces energy consumption while still meeting the requirements of low-consumption applications

Inventive Principle:

Principle #16Partial or excessive 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 solution provides a simple, cost-effective, and compact reference voltage generator circuit that maintains accuracy in normal modes and reduces consumption in low-consumption modes, allowing for efficient power management and reduced space usage.

Implementation Method 1

The first transistor and the second transistor are configured to generate a current proportional to an absolute temperature of the first variable resistor

Methodology Applied

Scientific EffectThermal voltage effect:

Implementation Method 2

An operational amplifier has a first input connected to the first transistor via the first variable resistor and a second input connected to the second transistor

Methodology Applied

Scientific EffectOperational amplification:

Implementation Method 3

A current mirror is controlled by an output of the operational amplifier and configured to replicate the current proportional to an absolute temperature of the second variable resistor

Methodology Applied

Scientific EffectCurrent mirroring:

Data Source

PatentUS12530044B2Microcontroller including a reference voltage generator circuit

Publication Date: 2026.01.20 STMICROELECTRONICS INT NV

AI summary

A microcontroller includes a reference voltage generator circuit having a first transistor coupled as a diode, a second transistor coupled as a diode, a first variable resistor, an operational amplifier having a first input connected to the first transistor via the first variable resistor, and a second input connected to the second transistor, and second variable resistor having a first terminal connected to the second transistor and to the second input of the operational amplifier. A current mirror is controlled by an output of the operational amplifier and configured to replicate the current proportional to an absolute temperature of the second variable resistor. A current copier branch is connected to the second transistor via a switch, the current copier branch being configured to replicate the current proportional to the absolute temperature of the second variable resistor and inject the current through the second transistor.