Internal Capacitor Linear Regulator with Transient Dip Compensator

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Solution Overview

Problem

Existing switching regulators require an external capacitor to provide low impedance for driving power switches, which is inconvenient due to the need for additional pins and space, and does not allow for internal supply voltage generation.

Innovation Solution

A switching regulator design that utilizes internal capacitors to absorb switching energy, eliminating the need for an external capacitor by incorporating internal capacitors and Low-dropout voltage regulators (LDOs) to generate intermediate supply voltages for power transistors, allowing for reduced gate drive voltage stress and efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an external capacitor is used to provide low impedance for driving power switches, then the switching energy can be absorbed effectively, but additional pins and space are required

Engineering Contradiction:

Improveswitching energy absorptionVSAvoidnumber of pins and external components

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the external capacitor function with internal circuit elements by merging the capacitor into the integrated circuit chip itself. The internal capacitor is connected to the LDO output and works in conjunction with the power switch drive circuitry to absorb switching energy, eliminating the need for separate external capacitor components and pins.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent implements a nested structure where the capacitor is embedded within the integrated circuit chip, nested inside the regulator architecture. The internal capacitor is positioned within the chip boundaries and integrated with the LDO and power switch drive circuitry, creating a compact nested arrangement that eliminates external components.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Reliability

If an external capacitor is used for driving power switches, then low impedance is provided, but additional space is required to house the external capacitor

Engineering Contradiction:

Improvelow impedance driveVSAvoidspace for external capacitor

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent merges the capacitor function with the integrated circuit chip by integrating the capacitor internally. This consolidation eliminates the need for separate external capacitor components and the PCB space they would occupy, while maintaining the low impedance drive capability through the internal capacitor's proximity to the power switch gates.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The capacitor is nested within the integrated circuit chip structure, placed inside the chip boundaries rather than externally. This nested arrangement provides the low impedance drive function while eliminating the external space requirements, as the capacitor resides within the existing chip footprint.

Inventive Principle:

Principle #7Nested doll (Nesting)

3Device complexity

If internal capacitors are used to eliminate external capacitors, then integration is improved and space is reduced, but the internal capacitor must handle switching energy absorption

Engineering Contradiction:

Improveintegration levelVSAvoidswitching energy handling

Core Design Contradiction:

Device complexityVSPower

Solution Approach 1:

The patent introduces the LDO as an intermediary component between the power source and the internal capacitor. The LDO regulates the voltage supplied to the internal capacitor and manages the power delivery, allowing the internal capacitor to absorb switching energy effectively while protecting it from excessive power stress that would occur with direct connection to the unregulated input.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the voltage parameter by using the LDO to provide a regulated intermediate voltage to the internal capacitor, rather than connecting the capacitor directly to the unregulated input voltage. This parameter transformation allows the internal capacitor to operate at a controlled voltage level suitable for its capacitance value, enabling it to handle switching energy absorption without being overwhelmed by excessive power.

Inventive Principle:

Principle #35Parameter changes

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

Enables compact and efficient operation of switching regulators without external capacitors, reducing the risk of transistor stress and improving integration by using internal capacitors and LDOs to manage voltage regulation and compensation.

Implementation Method 1

internal capacitors to absorb switching energy

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

Low-dropout voltage regulators (LDOs) to generate intermediate supply voltages for power transistors

Methodology Applied

Scientific EffectVoltage regulation:

Data Source

PatentUS8975880B2Internal capacitor linear regulator with transient dip compensator for internal-switch switching regulator

Publication Date: 2015.03.10 AVAGO TECHNOLOGIES INTERNATIONAL SALES PTE LTD

AI summary

A switching regulator arrangement utilizes internal capacitors rather than external capacitors for driving output power transistors. Low-dropout linear voltage regulators together with a dip compensation circuit provide an intermediate supply voltage for driving power transistors under circumstances in which a supply voltage is greater than a gate drive voltage of the power transistor, allowing for a more efficient absorption of transient current.