Digital DC-DC Converter Control Without ADC Overhead
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Solution Overview
Problem
Existing DC-DC converters suffer from energy loss during conversion and require expensive, large analog circuitry for accurate voltage regulation, which is particularly problematic for battery-powered devices.
Innovation Solution
A digitally controlled DC-DC converter utilizing a digital regulation loop with a power stage, controller, and a digital-to-analog converter (DAC) to regulate output voltage without the need for an analog-to-digital converter (ADC), using a controller with an error amplifier, comparator, and logic circuit to adjust the duty cycle based on a comparison signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If precision analog voltage regulation circuitry is used to control output voltage, then voltage regulation accuracy is improved, but device cost and circuit area increase
Solution Approach 1:
The patent replaces the mechanical/analog regulation system with a digital control system. Specifically, it substitutes precision analog voltage regulation circuitry with a digital regulator that uses a digital-to-analog converter (DAC) to generate control signals. The controller compares the output voltage to a reference voltage and adjusts the DAC control word digitally, eliminating the need for complex precision analog components while maintaining regulation accuracy.
Solution Approach 2:
The patent changes the regulation approach from analog parameter adjustment to digital parameter control. Instead of using analog circuitry to continuously adjust voltage, the system uses a digital controller that modifies the DAC control word based on voltage error signals. This digital parameter change approach simplifies the hardware while preserving control precision through software-based algorithms.
2Measurement precision
If a digital regulation loop with high quality ADC is used, then output voltage accuracy is improved, but device cost and IC area increase
Solution Approach 1:
The patent extracts and removes the ADC component from the digital regulation loop. Instead of using an ADC to convert the output voltage to digital form for comparison, the system directly uses a voltage comparator to generate an error signal that feeds into the digital controller. This extraction eliminates the need for expensive, large-area ADC hardware while maintaining the benefits of digital control.
Solution Approach 2:
The patent inverts the traditional digital regulation approach. Rather than converting the output voltage to digital (ADC) and then processing it, the system uses an analog comparator to generate a digital error signal directly from the voltage difference. This inversion allows digital control without requiring an ADC, simplifying the overall architecture.
3Power
If switching power supplies with duty cycle control are used, then voltage conversion efficiency is improved, but energy loss during conversion increases
Solution Approach 1:
The patent implements a feedback mechanism where the output voltage is continuously monitored and compared to a reference voltage. The error signal from this comparison feeds back to the digital controller, which adjusts the DAC control word to minimize the voltage error. This closed-loop feedback ensures efficient voltage conversion by dynamically optimizing the duty cycle based on actual output conditions, reducing energy losses.
Solution Approach 2:
The system uses its own output voltage to generate the control signal through the feedback loop. The voltage comparator and digital controller work together to automatically adjust the switching duty cycle based on the output voltage level, enabling the power supply to self-regulate and minimize energy losses without external intervention.
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 provides accurate and cost-effective voltage regulation, reducing energy loss and maintaining consistent output voltage without the need for expensive ADCs, suitable for battery-powered devices.
Implementation Method 1
a digital-to analog converter coupled to the adjustment block, the power stage input voltage and the logic circuit to receive the control word from the logic circuit and to generate a converter voltage representing the control word using another voltage
Data Source
AI summary
A digitally controlled DC-DC converter has a power stage coupled to an input voltage and to a control signal to generate an output voltage in response to the control signal. A controller generates the control signal and has an adjustment block to compare the output voltage to a reference voltage to generate a comparison signal, a logic circuit coupled to the adjustment block to receive the comparison signal and to generate the control signal in response to the comparison signal using a control word, and a digital-to analog converter coupled to the adjustment block, the power stage input voltage and the logic circuit to receive the control word from the logic circuit and to generate a converter voltage representing the control word using another voltage, the converter voltage being applied to the adjustment block to adjust the comparison signal.