Power Amplifier Bias Current Limiting for RFFE Burnout Prevention

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Solution Overview

Problem

The RFFE circuit in electronic devices is prone to burnout due to overcurrent caused by changes in internal resistance, which can lead to excessive voltage and current flowing through the circuit, damaging power amplifiers.

Innovation Solution

An overcurrent protection circuit is implemented to limit the current supplied to the power amplifier, comprising a regulator, current measurer, configurer, current comparator, and controller that monitor and control the bias voltage and current to prevent excessive flow, using a method that configures maximum permissible current values for each power amplifier based on their characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a constant level of voltage is supplied from the battery to the RFFE circuit, then stable operation is achieved under normal conditions, but overcurrent occurs when internal resistance changes, causing burnout

Engineering Contradiction:
Improvestable operationVSAvoidovercurrent
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The protection circuit performs preliminary detection of current levels before overcurrent damage occurs. The current detector continuously monitors the current flowing through the RFFE circuit, and when a predetermined threshold is approached, the controller preemptively adjusts the voltage supply to prevent overcurrent conditions before they cause burnout.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The protection circuit implements a feedback mechanism where the current detector continuously monitors actual current levels and feeds this information back to the controller. The controller then adjusts the voltage supply from the battery based on this feedback, dynamically maintaining safe operating conditions while enabling stable operation during normal conditions.

Inventive Principle:
Principle #23Feedback

2Power

If overvoltage is instantaneously supplied from the battery to the RFFE circuit, then power delivery is improved, but overcurrent flows through the IC causing interruption or burnout

Engineering Contradiction:
Improvepower deliveryVSAvoidcircuit integrity
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The protection circuit performs preliminary detection of current levels before overcurrent damage occurs. The current detector continuously monitors the current flowing through the RFFE circuit, and when a predetermined threshold is approached, the controller preemptively adjusts the voltage supply to prevent overcurrent conditions before they cause burnout.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The protection circuit provides beforehand cushioning by preparing the voltage supply adjustment mechanism in advance. When overcurrent conditions are detected, the controller rapidly reduces the voltage supply, cushioning the circuit against the harmful effects of overcurrent and preventing burnout of the IC components.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Device complexity

If the number of components in the RFFE circuit is reduced, then device complexity is lowered, but protection against overcurrent requires additional circuit elements

Engineering Contradiction:
Improvecomponent countVSAvoidovercurrent protection
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The protection circuit merges multiple functions into integrated components. The controller integrates the voltage regulation and current protection functions, while the current detector combines sensing and signal processing capabilities. This merging approach provides comprehensive overcurrent protection without proportionally increasing the total component count.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The protection circuit implements multi-functional components that serve multiple purposes. The current detector not only monitors for overcurrent conditions but also provides information for optimizing power delivery. The controller simultaneously manages voltage regulation, current protection, and power optimization, reducing the need for separate dedicated components for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 effectively prevents power amplifier burnout by limiting current flow, ensuring stable operation and extending the lifespan of the electronic device's components.

Implementation Method 1

a regulator for controlling a supply voltage supplied from a battery to the RFFE circuit

Methodology Applied
Scientific EffectVoltage regulation:

Implementation Method 2

a current detector for detecting a current level flowing through the RFFE circuit when the supply voltage is supplied to the RFFE circuit

Methodology Applied
Scientific EffectElectrical resistance measurement: Electrical Resistance

Implementation Method 3

a controller for controlling the regulator, wherein the controller limits the supply voltage when the current level exceeds a reference current level

Methodology Applied
Scientific EffectVoltage control:

Data Source

PatentEP3843264B1Protection circuit in electronic device and method therefor
Publication Date: 2023.10.04 SAMSUNG ELECTRONICS CO LTD
  • EP3843264B1 patent drawingFigure 1
  • EP3843264B1 patent drawingFigure 2
  • EP3843264B1 patent drawingFigure 3

AI summary

An electronic device and method thereof of are provided to prevent burnout due to overcurrent. An electronic device includes a power amplifier configured to amplify a transmission signal; a battery configured to provide a bias voltage to the at least one power amplifier; and an overcurrent protection circuit configured to prevent overcurrent from flowing through the power amplifier. The overcurrent protection circuit includes a configurer configured to configure a reference current value, based on the power amplifier; a measurer configured to measure a bias current value due to the bias voltage; a comparator configured to compare the measured bias current value with the reference current value; and a controller configured to recognize overcurrent flowing through the power amplifier and control provision of the bias voltage, based on a result of the comparison.