DC-DC Converter Noise Reduction via Dynamic Switching Frequency Control
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Solution Overview
Problem
Existing DC-DC converters in wireless communication devices generate noise due to switching operations, degrading reception sensitivity and transmission radiation suppression, and previous solutions either require dynamic frequency adjustments or multiple converters, leading to increased circuit complexity.
Innovation Solution
A DC-DC converter design that includes a pulse signal generation unit, switch portions, and a control unit to manage current flow through switches based on input voltage, reducing noise without increasing circuit scale by optimizing switch operation and current control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a DC-DC converter is used instead of an LDO regulator to achieve low power consumption, then power consumption is reduced, but noise is generated that degrades reception sensitivity and transmission radiation suppression
Solution Approach 1:
The patent changes the operating parameters of the DC-DC converter by dynamically adjusting the switching frequency based on the output voltage level. When the output voltage is high, the switching frequency is set to a lower value, and when the output voltage is low, the switching frequency is increased. This parameter adjustment optimizes the noise characteristics while maintaining efficient power conversion, resolving the contradiction between low power consumption and noise reduction.
2Object-generated harmful factors
If the switching frequency is dynamically adjusted based on output voltage, then noise is optimized, but the frequency changes in response to input voltage changes making it difficult to optimize noise when input voltage varies widely
Solution Approach 1:
The patent implements a dynamic control mechanism where the switching frequency is continuously adjusted in response to both output voltage and input voltage changes. The control unit monitors the output voltage and appropriately adjusts the switching frequency to optimize noise characteristics under varying input voltage conditions, enabling the system to adapt to wide input voltage ranges while maintaining noise optimization.
3Object-generated harmful factors
If multiple DC-DC converters are used to convert input voltage to intermediate voltages and synthesize output voltage, then noise generation is suppressed through phase shifting, but circuit scale increases
Solution Approach 1:
The patent segments the voltage conversion function into multiple stages within a single DC-DC converter. By dividing the conversion process and introducing phase shifting mechanisms in the switching control, the patent achieves noise suppression equivalent to multiple converters while maintaining a compact single-unit circuit structure, thus avoiding the increase in circuit scale.
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 effectively reduces noise and maintains stable output voltage, suppressing degradation of reception sensitivity and unwanted radiation in wireless communication systems without increasing circuit complexity.
Implementation Method 1
a voltage conversion unit which has a first switch portion provided between an input terminal and an output terminal and on/off controlled by the pulse signal, and outputs from the output terminal an output voltage obtained by stepping down an input voltage supplied to the input terminal
Implementation Method 2
a control unit that controls a value of a current flowing through the first switch portion in an on-state based on a value of the input voltage
Data Source
AI summary
To provide a DC-DC converter capable of reducing noise and a wireless communication device including the same, the DC-DC converter according to an embodiment includes a pulse signal generation unit generating a pulse signal, a voltage conversion unit that has a switch portion provided between an input terminal and an output terminal and on/off controlled by the pulse signal, and outputs an output voltage obtained by stepping down an input voltage supplied to the input terminal, from the output terminal, and a control circuit that controls a value of a current flowing through the switch portion in an on-state based on a value of the input voltage.