Voltage Converter Loop Control Parasitic Ground Resistance

Solution Overview

Problem

In small-sized voltage converter systems, the combination of internal analog ground and power ground terminals as a single ground terminal introduces parasitic resistance, leading to poor load regulation due to voltage drops, especially at high output currents and low reference voltages, affecting the accuracy of voltage regulation.

Innovation Solution

A voltage converter system with compensation circuitry that adjusts the reference voltage based on the state of the switches, using sensing transistors and a comparator to compensate for voltage drops across parasitic resistors, ensuring accurate regulation by providing a compensated reference voltage when the second switch is on.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If internal analog ground and power ground terminals are combined as a single ground terminal in small-sized voltage converter systems, then device size is reduced, but parasitic resistance increases causing voltage drops and poor load regulation

Engineering Contradiction:

Improvedevice sizeVSAvoidparasitic resistance

Core Design Contradiction:

Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent segments the ground reference into two separate terminals: an internal analog ground terminal for the reference voltage and a power ground terminal for the output. This segmentation prevents the reference voltage from being affected by parasitic resistance in the power ground path, thereby maintaining accurate voltage regulation even in compact designs where ground terminals must be closely spaced.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces separate ground terminals as intermediary reference points to isolate the sensitive reference voltage from the high-current power ground path. The internal analog ground terminal acts as an intermediary that provides a clean reference without exposing it to the parasitic resistance effects that occur in the power delivery path.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If ground terminals are combined to reduce size, then manufacturing complexity is reduced, but voltage regulation accuracy deteriorates due to parasitic resistance-induced drops

Engineering Contradiction:

Improvemanufacturing complexityVSAvoidvoltage regulation accuracy

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent segments the ground reference into two separate terminals: an internal analog ground terminal for the reference voltage and a power ground terminal for the output. This segmentation prevents the reference voltage from being affected by parasitic resistance in the power ground path, thereby maintaining accurate voltage regulation even in compact designs where ground terminals must be closely spaced.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different ground quality requirements to different parts of the circuit: the internal analog ground terminal provides a high-quality, low-impedance reference for the control circuitry, while the power ground terminal handles high-current switching. This local differentiation of ground quality ensures accurate regulation without requiring complex external grounding schemes.

Inventive Principle:

Principle #3Local quality

3Device complexity

If a single ground terminal is used, then device complexity is reduced, but load regulation performance worsens at high output currents due to voltage drops across parasitic resistance

Engineering Contradiction:

Improvedevice complexityVSAvoidload regulation performance

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent segments the ground reference into two separate terminals: an internal analog ground terminal for the reference voltage and a power ground terminal for the output. This segmentation prevents the reference voltage from being affected by parasitic resistance in the power ground path, thereby maintaining accurate voltage regulation even in compact designs where ground terminals must be closely spaced.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent creates separate equipotential zones for the reference voltage and the power output. By providing the reference voltage relative to the internal analog ground terminal rather than the power ground terminal, the control circuitry operates from a stable equipotential reference that is not disturbed by voltage drops in the power delivery path, ensuring reliable load regulation.

Inventive Principle:

Principle #12Equipotentiality

Data Source

PatentUS11646661B2Voltage converter with loop control

Publication Date: 2023.05.09 TEXAS INSTRUMENTS INC

AI summary

A voltage converter system includes a switch configured to operate in first and second states. Compensation circuitry is configured to provide: a certain reference voltage as a reference voltage when the switch has the second state; and a compensated reference voltage as the reference voltage when the switch has the first state. Control circuitry is configured to switch the switch between the first and second states based on the reference voltage and a feedback voltage generated based on an output voltage of the voltage converter system.