Power Source Circuit with Dual Control Paths for Voltage Accuracy
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Solution Overview
Problem
Conventional digitally controlled DC/DC converters face increased power consumption due to the need for high resolution in A/D converters and additional circuits for noise insulation and oscillation avoidance, which complicates accurate voltage control while consuming more power.
Innovation Solution
A power source circuit with a switching element controlled by a PWM signal, utilizing both digital and analog control paths to adjust the pulse width of the PWM signal based on integration and A/D conversion of differential voltage, allowing for accurate voltage control with reduced A/D converter resolution and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the LSB width of the A/D converter is decreased to improve resolution and output voltage accuracy, then measurement precision is improved, but power consumption is increased
Solution Approach 1:
The control system is divided into two separate paths: an analog control path that handles coarse adjustment and a digital control path that handles fine adjustment. This segmentation allows the A/D converter to operate at lower resolution while maintaining overall output voltage accuracy through the complementary analog path.
Solution Approach 2:
The invention changes the resolution parameter of the A/D converter to a lower value (reducing LSB width requirements) while compensating for the reduced precision by introducing an analog control path that operates in parallel to provide the necessary fine-tuning capability.
2Stability of the object's composition
If a differentiation circuit is added to avoid oscillation in voltage mode control, then stability is improved, but device complexity and power consumption are increased
Solution Approach 1:
The invention extracts the oscillation avoidance function from the main voltage mode control path and implements it separately through a dedicated delay circuit in the digital control path. This separation eliminates the need for a differentiation circuit in the analog path, reducing overall circuit complexity while maintaining stability.
Solution Approach 2:
A delay circuit is introduced as an intermediary element in the digital control path to provide the necessary phase compensation and prevent oscillation. This intermediary approach replaces the traditional differentiation circuit, achieving the same stability function with simpler circuitry.
3Productivity
If current mode control is used to improve response speed, then productivity is improved, but power consumption is increased due to inductor current detection circuit
Solution Approach 1:
The invention merges the advantages of both voltage mode and current mode control by combining a voltage mode control structure with digital PID control and a delay circuit. This hybrid approach achieves fast response characteristics similar to current mode control without requiring the power-consuming inductor current detection circuit.
Solution Approach 2:
The invention substitutes the mechanical/electrical current detection mechanism with a digital control approach using voltage sampling and digital processing. This replacement eliminates the need for complex current sensing hardware while maintaining fast response through digital PID control algorithms.
4Reliability
If digital control is used to insulate from noise influence, then reliability is improved, but measurement precision deteriorates due to limited A/D converter resolution
Solution Approach 1:
The control system is segmented into analog and digital paths, where the analog path preserves high-resolution voltage information immune to digital noise, while the digital path provides noise-insulated control signals. This segmentation allows both noise insulation and high measurement precision to coexist.
Solution Approach 2:
An analog control path acts as an intermediary between the digital control signals and the output voltage, translating digital commands into precise analog voltage adjustments without introducing digital noise. This intermediary preserves measurement precision while maintaining the noise insulation benefits of digital control.
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 enables accurate control of output voltage while minimizing power consumption by combining digital PID control with analog integration, allowing for efficient operation with reduced A/D converter resolution and avoiding unnecessary power consumption.
Implementation Method 1
a first control path that includes an integration circuit that outputs an integration signal provided by integrating a differential voltage between the output voltage and a reference voltage
Implementation Method 2
a second control path that includes an A/D converter that converts the differential voltage between the output voltage and the reference voltage into a digital signal
Implementation Method 3
a switching element with a main current path that is connected between an input terminal where an input voltage is applied thereto and an output terminal that supplies an output voltage thereto where turning on/off thereof is controlled by a PWM driving signal
Data Source
AI summary
According to an embodiment, a power source circuit includes a switching element that is connected between an input terminal and an output terminal, a driving circuit that supplies a PWM driving signal to the switching element, a first control path that integrates a differential voltage between an output voltage and a reference voltage to output a first control signal, a second control path that converts the differential voltage into a digital signal to output a second control signal, and a PWM signal generation circuit that generates a PWM signal dependent on the first and second control signals.