DC to DC Converter PWM Controller Adaptive Slope Compensation

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Solution Overview

Problem

Existing DC to DC converters and PWM controllers require external components for frequency-dependent slope compensation, leading to increased costs and circuit complexity, and are not adaptable to a wide range of switching frequencies.

Innovation Solution

The implementation of a frequency adaptive slope compensation circuitry using a phase locked loop (PLL) and slope generator circuit within a single integrated circuit, which generates a slope compensation ramp signal with an amplitude proportional to the operating frequency, eliminating the need for external components and dedicated pins.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If external components are used for frequency-dependent slope compensation, then the converter can operate over a wide range of frequencies, but the circuit complexity and component costs increase

Engineering Contradiction:

Improveoperating frequency rangeVSAvoidcircuit complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the slope compensation function with the PWM controller by integrating a frequency-dependent compensation circuit inside the controller. The compensation ramp is generated using an internal oscillator and resistive divider network, eliminating the need for external frequency-adjustment components while maintaining adaptability across different operating frequencies.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The PWM controller is designed with a universal compensation circuit that automatically adapts to different switching frequencies through its internal frequency-dependent network. A single controller design can operate across a wide frequency range without requiring external component changes, making it universally applicable to various converter configurations.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If external components are used for frequency-dependent slope compensation, then the converter can operate over a wide range of frequencies, but the circuit board area and component costs increase

Engineering Contradiction:

Improveoperating frequency rangeVSAvoidcircuit board area

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent consolidates multiple functions (PWM generation, error amplification, and frequency-dependent slope compensation) into a single integrated controller chip. This eliminates the need for external resistors, capacitors, and other frequency-adjustment components, thereby reducing circuit board area and component costs while maintaining wide frequency adaptability.

Inventive Principle:

Principle #5Merging (Combining)

3Adaptability or versatility

If a dedicated pin is provided for external compensation adjustment, then the compensation slope can be adjusted for different frequencies, but the integrated circuit pin count and costs increase

Engineering Contradiction:

Improvecompensation slope adjustmentVSAvoidpin count

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The controller incorporates a universal compensation circuit that automatically generates the appropriate compensation slope for any operating frequency without requiring external adjustment pins. The internal frequency-dependent network self-adjusts the compensation based on the oscillator frequency, eliminating dedicated compensation pins and reducing overall pin count.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The compensation circuit is designed to self-adjust based on the internal oscillator frequency. The frequency-dependent resistive divider network automatically provides the correct compensation slope for the current operating frequency without requiring external intervention or dedicated adjustment pins, making the system self-sufficient.

Inventive Principle:

Principle #25Self-service

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 allows for self-adaptation of slope compensation to varying operating frequencies, reducing circuit complexity and component costs, while enabling universal use across different DC to DC converter applications.

Implementation Method 1

The compensation circuit includes a phase locked loop (PLL) circuit and a slope generator circuit, with the PLL receiving a clock signal and providing a control output signal having an amplitude generally proportional to the frequency of the clock signal

Methodology Applied

Scientific EffectPhase locked loop:

Implementation Method 2

The slope generator circuit receives the PLL control output signal and provides the slope compensation ramp signal to the summation circuit having a repeating ramp waveform with an amplitude varying at least partially according to the amplitude of the control output signal from the PLL

Methodology Applied

Scientific EffectRamp waveform generation:

Data Source

PatentUS9325233B2DC to DC converter and PWM controller with adaptive compensation circuit

Publication Date: 2016.04.26 TEXAS INSTRUMENTS INC

AI summary

DC to DC converters and PWM controllers are presented in which a slope compensation ramp signal is provided for current control operation via a frequency adaptive compensation circuit with a phase locked loop that provides a control output signal having an amplitude generally proportional to the frequency of a clock signal, and a slope generator circuit generating the slope compensation ramp signal with an amplitude generally proportional to the control output signal amplitude.