New Fixed-Frequency Digital Control to Improve the Light-Load Efficiency of an Isolated Regulated Converter
Abstract
:1. Introduction
2. Working Principles in DCM
2.1. Soft-Switching of the Primary Switch
2.2. The Voltage–Second Balance Method
2.3. Operation Modes
3. The Proposed Control Scheme
3.1. Control Diagram in DCM
3.2. The Principle of Control Flow
3.3. Design Considerations
3.3.1. Dead Time in DCM
3.3.2. The Voltage Threshold of the Compout Signal
3.3.3. The Voltage Threshold of the Compout Variation Rate
3.3.4. Controller Selection and Comparison
4. Circuit Design
4.1. Hardware Parameters
4.2. Software Parameters
4.3. Power Loss, Ripple, and Regulation Estimation
5. Experimental Results
5.1. Waveforms in DCM
5.2. Transient, Ripple, and Regulation
5.3. Efficiency Discussion and Comparison
6. Conclusions
Author Contributions
Funding
Data Availability Statement
Conflicts of Interest
References
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Controller Type (Company) | Price (Source: DigiKey) | Released Year | Description |
---|---|---|---|
dsPIC33CK32MP502 (Microchip) | US$3.4 | 2018 | Twenty-Eight-Pin Digital Signal Controllers with High-Resolution PWM |
LTC3726 (ADI) | US$5.8 | 2008 | Secondary-Side Synchronous Forward Controller |
LTC3766 (ADI) | US$11 | 2016 | High Efficiency Secondary-Side Synchronous Forward Controller |
SC4910A (Semtech) | US$2.5 | 2005 | Current-Mode PWM Controller with Complementary Output |
Parameters | Value |
---|---|
Input voltage (Vi) | 20 V to 36 V (28 V typical) |
Output voltage (VO) | 15 V |
Maximum output power (PO) | 100 W |
Switching frequency (fs) | 350 kHz |
Transformer turns ratio (N) | 3:5 |
Output inductance (LO) | 12 μH |
Magnetizing inductance (Lm) | 33 μH |
Output capacitance (CO) | 110 μF |
Transformer leakage inductance (Lk) | 0.1 μH |
Current transformer turns ratio (NS) | 100:1 |
Sampling resistor (RS) | 22 Ω |
Total Input Power (@ Load Current) | Power Board Loss | Control Board Loss | Total Efficiency |
---|---|---|---|
3.7 W (0.2 A) | 0.4 W | 0.29 W | 81.3% |
7.3 W (0.4 A) | 0.94 W | 0.3 W | 82.9% |
10.7 W (0.6 A) | 1.34 W | 0.31 W | 84.5% |
14 W (0.8 A) | 1.73 W | 0.31 W | 85.5% |
17.1 W (1 A) | 1.81 W | 0.31 W | 87.6% |
Author, Year | Topology | Additional Component Count | Light-Load Efficiency, (Load Range) | Maximum Output Power | Application Fields |
---|---|---|---|---|---|
This paper | SR forward | 0 | 81–87%, (0–20%) | 100 W | Industry, aerospace, military |
[10], 2020 | Flyback | 0 | 82–88%, (0–30%) | 60 W | Fast-charging |
[21], 2016 | Flyback | 0 | 84.9–87.4%, (8–25%) | 40 W | Fast-charging |
[22], 2018 | Forward | >2, ZVT circuit | <86%, (<20%) | 150 W | Home appliances, industry |
[23], 2020 | Forward | >3, ZCT circuit | <86%, (<20%) | 200 W | Medical, industry |
[24], 2017 | Buck | >3, ZVS circuit | <91%, (<20%) | 500 W | Industry |
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Ma, C.; Wang, J.; Wang, K.; Long, B. New Fixed-Frequency Digital Control to Improve the Light-Load Efficiency of an Isolated Regulated Converter. Electronics 2023, 12, 575. https://doi.org/10.3390/electronics12030575
Ma C, Wang J, Wang K, Long B. New Fixed-Frequency Digital Control to Improve the Light-Load Efficiency of an Isolated Regulated Converter. Electronics. 2023; 12(3):575. https://doi.org/10.3390/electronics12030575
Chicago/Turabian StyleMa, Cong, Junfeng Wang, Kai Wang, and Baiguang Long. 2023. "New Fixed-Frequency Digital Control to Improve the Light-Load Efficiency of an Isolated Regulated Converter" Electronics 12, no. 3: 575. https://doi.org/10.3390/electronics12030575