Resonant Converter Controller Integrating Current and Capacitor Voltage Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing resonant converter control methods face challenges in efficiently measuring both capacitor voltage and primary current, especially in high power and high frequency applications, where noise sensitivity and pin limitations hinder clean signal measurement and lead to disturbance issues.
Innovation Solution
The solution involves integrating a current measurement circuit with a sense resistor or transformer to generate the capacitor voltage signal internally, reducing the need for a separate capacitor voltage sensing pin, and using differential amplification to minimize noise interference, thereby allowing for improved current measurement and reduced pin count.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate capacitor voltage sensing and current measurement circuits are used, then measurement accuracy is improved, but device complexity and pin count increase
Solution Approach 1:
The patent combines capacitor voltage sensing and current measurement functions into a single pin by using an integrator to generate the capacitor voltage signal from the measured current. This merging eliminates the need for separate sensing pins and reduces overall device complexity while maintaining measurement accuracy through the mathematical relationship between current and voltage in the resonant capacitor.
Solution Approach 2:
The single sensing pin serves multiple functions: it measures both the primary current and generates the capacitor voltage signal through integration. This multi-functional approach allows one pin to replace what would traditionally require two separate pins, reducing pin count while maintaining full measurement capability.
2Measurement precision
If traditional voltage sensing is used, then capacitor voltage measurement is achieved, but noise sensitivity increases in high frequency applications
Solution Approach 1:
The patent replaces direct voltage sensing with a current-based measurement approach where the capacitor voltage signal is generated through integration of the measured current. This substitution of the sensing mechanism avoids direct high-impedance voltage nodes that are susceptible to noise, and instead uses low-impedance current measurement that is inherently more noise-resistant in high-frequency applications.
3Adaptability or versatility
If multiple sensing pins are used for current and voltage measurement, then measurement functionality is improved, but power consumption increases
Solution Approach 1:
The patent merges current measurement and voltage sensing functionality into a single pin, reducing the total number of active sensing elements. This reduction in the number of sensing pins and associated circuitry directly lowers power consumption while maintaining full sensing functionality through the integrator-based voltage signal generation.
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 approach enables clean and disturbance-free measurement of primary current, reduces the number of pins and components, and maintains control functionality equivalent to direct capacitor voltage measurement, while enhancing noise resistance and power efficiency.
Implementation Method 1
a sense resistor in series with the resonant capacitor
Implementation Method 2
a current sense transformer
Implementation Method 3
a differential amplifier with differential inputs connected across the sense resistor configured to produce the current measurement signal
Implementation Method 4
an integrator configured to receive a current measurement signal from the current measurement circuit and to produce a capacitor voltage signal indicative of the voltage at the resonant capacitor
Data Source
AI summary
Various embodiments relate to a converter controller configured to control a resonant converter, including: an integrator configured to receive a current measurement signal from a current measurement circuit in the resonant converter and to produce a capacitor voltage signal indicative of the voltage at the resonant capacitor; a control logic configured to produce a high side driver signal, a low side driver signal, a symmetry error signal based upon the capacitor voltage signal and the current measurement signal; and a symmetry controller configured to produce a symmetry correction signal based upon the symmetry error signal, wherein the symmetry error signal is input into the integrator to control the duty cycle of the high side driver signal and the low side driver signal, wherein the high side driver signal and the low side driver signal control the operation of the resonant converter.