Boost Converter Current Estimation Using Ripple Compensation

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Solution Overview

Problem

Existing boost converter systems face challenges in accurately monitoring and regulating the average inductor current, which is crucial for preventing excessive current draw from batteries and ensuring efficient voltage conversion.

Innovation Solution

The implementation of current detection circuitry that generates an average inductor current signal by combining a peak inductor current signal with a ripple current estimate signal, along with compensation circuitry to correct errors in the ripple current estimate based on actual inductor current monitoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If existing boost converter systems monitor peak inductor current only, then the circuit complexity is low, but the measurement precision of average inductor current is insufficient

Engineering Contradiction:

Improveaverage inductor current measurement precisionVSAvoidcurrent detection circuitry complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces ripple current estimate signal as an intermediary element to bridge the gap between peak inductor current measurement and average inductor current determination. By adding this intermediate signal that represents the ripple component, the system can derive average current without directly measuring it, thus improving measurement precision while keeping the circuit relatively simple

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces direct physical measurement of average inductor current with a signal processing approach. Instead of using complex measurement circuitry to directly sense average current, the system substitutes this with mathematical operations on easily obtainable signals (peak current signal and ripple current estimate), achieving high precision measurement through electronic signal manipulation rather than complex physical measurement

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If ripple current estimate is applied to peak inductor current signal, then the average inductor current regulation precision is improved, but the device complexity increases

Engineering Contradiction:

Improveaverage inductor current regulation precisionVSAvoidcompensation circuitry complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent implements feedback by using the actual inductor current measurement to validate and adjust the ripple current estimate. The compensation circuitry compares the estimated average current (derived from peak current and ripple estimate) with the actual measured average current, and uses this feedback to refine the ripple current estimate, thereby improving regulation precision while managing circuit complexity through iterative correction

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent applies partial action by implementing compensation only when necessary - the compensation circuitry activates to correct ripple current estimate errors based on actual current monitoring, rather than continuously operating complex compensation mechanisms. This approach achieves high precision regulation by applying corrective action selectively rather than constantly

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

This solution enables precise regulation of the average inductor current, thereby optimizing energy transfer and extending battery life in portable electronic devices.

Implementation Method 1

the inductor stores some energy by generating a magnetic field

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS20250070671A1Current estimation in a power converter

Publication Date: 2025.02.27 CIRRUS LOGIC INC

AI summary

Current detection circuitry for generating an average inductor current signal indicative of an average inductor current during an operational cycle of power converter circuitry, the current detection circuitry comprising: circuitry for generating a peak inductor current signal indicative of a peak inductor current during the operational cycle; and circuitry for applying a ripple current estimate signal, indicative of an estimate of half of a ripple current in the power converter circuitry, to the peak inductor current signal to generate the average inductor current signal, wherein the ripple current is equal to a difference between the average inductor current and the peak inductor current.