Voltage Regulator Transient Response Enhancement

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Solution Overview

Problem

Voltage regulators in portable electronic devices face challenges in responding quickly to transient load changes, leading to electrical spikes and increased quiescent-state current, which affects performance and battery duration.

Innovation Solution

A voltage regulating apparatus with a power transistor, feedback circuit, amplifier, and transient enhancement unit that monitors source and sink currents to rapidly adjust the gate voltage of the power transistor, allowing for quicker response to load changes while minimizing quiescent-state current.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the voltage regulator uses a conventional amplifier to drive the power transistor, then the circuit structure is simple, but the response to transient load changes is slow causing electrical spikes

Engineering Contradiction:

Improvetransient response speedVSAvoidcircuit structure complexity

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The amplifier is segmented into two independent current units: a source current unit and a sink current unit. This segmentation allows each unit to independently drive the power transistor in opposite directions, enabling rapid response to transient load changes without requiring a complex high-bandwidth amplifier design.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The source and sink current units are designed with asymmetric characteristics optimized for their specific functions. The source current unit is optimized for charging the power transistor gate, while the sink current unit is optimized for discharging, allowing each to operate at optimal performance for its specific task rather than requiring a balanced general-purpose amplifier.

Inventive Principle:

Principle #3Local quality

2Speed

If the voltage regulator increases the amplifier driving capability to speed up response, then the transient response improves, but the quiescent-state current increases

Engineering Contradiction:

Improvetransient response speedVSAvoidquiescent-state current

Core Design Contradiction:

SpeedVSUse of energy by moving object

Solution Approach 1:

The voltage regulator dynamically switches between different operating modes by activating either the source current unit or the sink current unit based on the transient condition detected. During normal operation, the regulator maintains low quiescent current by using only minimal bias currents. During transients, the appropriate current unit is activated to provide the necessary driving current, thus achieving fast response only when needed.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The regulator changes the operating parameters of the amplifier by switching between different current source configurations. The source and sink current units have different current levels optimized for their respective functions, allowing the system to achieve high driving capability during transients while maintaining low quiescent current during steady-state operation.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the voltage regulator uses separate source and sink current units, then the transient response is enhanced, but the device complexity increases

Engineering Contradiction:

Improvetransient load handlingVSAvoidamplifier structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The source and sink current units are merged into a single integrated amplifier structure that shares common circuit elements such as the compensation capacitor, feedback network, and power transistor gate connection. This merging reduces the overall device complexity compared to using two completely separate amplifier circuits, while still providing the benefits of independent source and sink current paths.

Inventive Principle:

Principle #5Merging (Combining)

4Object-affected harmful factors

If the voltage regulator responds quickly to load changes, then the electrical spikes are reduced, but the quiescent-state current grows

Engineering Contradiction:

Improveelectrical spikesVSAvoidquiescent-state current

Core Design Contradiction:

Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The regulator implements preliminary detection of transient conditions through the transient detection circuit that monitors the output voltage and load current. When a transient condition is detected, the appropriate current unit is activated in advance to prevent electrical spikes, rather than waiting for the spike to occur and then responding. This preliminary action allows fast response without continuously maintaining high driving capability that would increase quiescent current.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS9195244B2Voltage regulating apparatus with enhancement functions for transient response

Publication Date: 2015.11.24 REALTEK SEMICON CORP

AI summary

A voltage regulating apparatus is disclosed. The voltage regulating apparatus includes: a power transistor having a control terminal, a first terminal for receiving a power supply, and a second terminal for providing an output voltage; a feedback circuit coupled to the second terminal, configured for providing a feedback voltage according to the output voltage; an amplifier having a source current unit and a sink current unit, configured for driving the power transistor through the control terminal by use of the source and sink current units according to a reference voltage and the feedback voltage; and a transient enhancement unit configured for monitoring the source and sink current units, and regulating a voltage at the control terminal according to the monitored result.