TV Power Supply
TV Power Supply Working Principle and Architecture
Modern TV power supplies utilize a Switch-Mode Power Supply (SMPS) architecture. They convert mains AC voltage to DC voltage through AC-DC conversion. A typical architecture includes modules such as EMI filtering, a rectifier bridge, a PWM controller, power switching transistors, and a high-frequency transformer. The core principle involves high-frequency switching (typically 50kHz-1MHz) to achieve efficient power conversion. Compared to traditional linear power supplies, SMPS offers significant advantages in compact size and high efficiency (often exceeding 90%).
Key Diode Technology Applications
Silicon Carbide Diodes (SiC)
- Used in Power Factor Correction (PFC) circuits to replace silicon-based diodes.
- Leverage their high-voltage capability (up to 1700V) and high-temperature stability (junction temperature >200°C) to significantly reduce reverse recovery losses.
- For example, in 800V bus designs, SiC diodes can improve PFC efficiency by 2-3%.
Ultra-Fast Recovery Diodes
- Primarily used for secondary-side rectification, featuring extremely short recovery times (as low as 35ns).
- In LLC resonant topologies, their fast turn-off characteristic effectively suppresses voltage ringing and reduces switching losses.
- Typical application: Rectification for +12V outputs, operating at frequencies up to 500kHz.
Schottky Diodes
- Applied in low-voltage, high-current output stages (e.g., 3.3V/5V rails).
- Utilize their low forward voltage drop characteristic (~0.3V) to minimize conduction losses.
TVS Diodes (Transient Voltage Suppressors)
- Employed for surge protection, featuring response times in the picosecond (ps) range.
- Bidirectional TVS devices (e.g., SMBJ series) at the AC input can absorb lightning surge transients defined by the 8/20μs waveform, rated up to 6kV.
- New multi-layer stacked TVS devices can achieve peak power ratings up to 30kW even in compact 0402 packages.
Technology Development Trends
1.Higher Frequency Operation and Integration: GaN and SiC devices are enabling switching frequencies beyond 2MHz, driving the miniaturization of magnetic components.
2.Intelligent Protection: Diode modules integrating temperature/over-voltage detection are becoming prevalent.
3.Energy Efficiency Upgrades: Regulations like the EU CoC V9 standard, mandating standby power consumption below 0.5W, are driving the development of novel diode-based topologies.
4.Enhanced Reliability: Advanced chip passivation techniques are increasing diode Mean Time Between Failures (MTBF) to over 1 million hours.
This analysis demonstrates how advanced semiconductor devices enable performance breakthroughs in modern TV power supplies. As the cost of wide-bandgap semiconductors decreases, Silicon Carbide and Gallium Nitride devices are poised to further reshape power supply architecture design.
The advantages of SMC
SMC, as a globally leading power semiconductor device manufacturer with nearly 30 years of history, can provide customers with the most advanced, efficient, and cost-effective third-generation silicon carbide MOSFETs and silicon carbide JBS diodes. In addition, SMC has unique experience in silicon-based power diode devices, and its best-selling high-power ultra-fast recovery diodes, high current Schottky diodes, and other products are highly praised by customers worldwide. SMC's power semiconductor devices can provide higher efficiency, better reliability, good delivery time, and competitive prices for your products. SMC's professional service team around the world allows you to experience the ultimate customer service experience and safeguard your product design.
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