LM3445
- TRIAC Dim Decoder Circuit for LED Dimming
- Application Voltage Range 80 VAC to 277 VAC
- Capable of Controlling LED Currents Greater
Than 1 A - Adjustable Switching Frequency
- Low Quiescent Current
- Adaptive Programmable Off-Time Allows for
Constant Ripple Current - Thermal Shutdown
- No 120-Hz Flicker
- Low Profile 10-Pin VSSOP Package or 14-Pin
SOIC - Patented Drive Architecture
The LM3445 is an adaptive constant off-time AC/DC buck (step-down) constant current controller designed to be compatible with TRIAC dimmers. The LM3445 provides a constant current for illuminating high power LEDs and includes a TRIAC dim decoder. The dim decoder allows wide range LED dimming using standard TRIAC dimmers. The high frequency capable architecture allows the use of small external passive components. The LM3445 includes a bleeder circuit to ensure proper TRIAC operation by allowing current flow while the line voltage is low to enable proper firing of the TRIAC. A passive PFC circuit ensures good power factor by drawing current directly from the line for most of the cycle, and provides a constant positive voltage to the buck regulator. Additional features include thermal shutdown, current limit and VCC under-voltage lockout.
技術文件
| 重要文件 | 類型 | 標題 | 格式選項 | 下載最新的英文版本 | 日期 | |
|---|---|---|---|---|---|---|
| * | 資料表 | LM3445 TRIAC Dimmable Offline LED Driver datasheet (Rev. M) | PDF | HTML | 2015/11/30 | ||
| 白皮書 | Common LED Functions and LED Driver Design Considerations | 2020/9/21 | ||||
| 選擇指南 | Power Management Guide 2018 (Rev. R) | 2018/6/25 | ||||
| EVM User's guide | 120Vac Valley Fill Buck Triac Dimmable LED Driver | 2015/5/12 | ||||
| 應用說明 | AN-1656 Design Challenges of Switching LED Drivers (Rev. A) | 2013/5/3 | ||||
| EVM User's guide | AN-1935 LM3445 Off-Line TRIAC Dimmer LED Driver Demo Board (Rev. I) | 2013/5/1 | ||||
| 使用指南 | AN-2061 LM3445 A19 Edison Retrofit Evaluation Board (Rev. C) | 2013/5/1 | ||||
| 應用說明 | AN-2034 LM3445 -120VAC, 8W Isolated Flyback LED Driver (Rev. C) | 2013/5/1 | ||||
| 使用指南 | AN-1995 LM3445 208-277V AC Non-Isolated Evaluation PCB (Rev. B) | 2013/5/1 | ||||
| 應用說明 | An Improved Line Regulation Solution Used in LM3444/5 Non-Isolated LED Lighting | 2012/10/25 | ||||
| 使用指南 | 230 Vac Off-line Triac Dimmer Retrofit with 6 LEDs Reference Design User Guide | 2012/1/27 | ||||
| 應用說明 | AN-2069 LM3445 - 230VAC, 6W- 15W Isolated Flyback LED Driver (Rev. B) | 2010/11/23 |
設計與開發
如需其他條款或必要資源，請按一下下方的任何標題以檢視詳細頁面 (如有)。
LM3445EVM-695 — LM3445 120Vac 填谷式降壓 Triac 可調光 LED 驅動器評估模組
LM3445EVM-695 實作採用德州儀器 LM3445 積體電路的調光解決方案。LM3445 是一款自適應恆定關閉時間 AC/DC 降壓定電流控制器，內建相位調光解碼器。內部低功率數位控制器會連續分析線路週期，以實現形狀和對稱。接著會產生類比電流參考，並由功率轉換器級使用來調節輸出電流。使用為最佳化調光器相容、功率因數與 THD 所開發的控制演算法來操作類比參考。此解決方案採用恆定關閉時間控制，可實現低零件數量、高效率，並固有地提供切換頻率的變化。此變化可產生模擬的展頻效果，減輕轉換器的 EMI 特性，並允許使用較小的輸入濾波器。
PMP30439 — 230 V 輸入至 180 V 輸出於 200 mA 定電流 LED 驅動器參考設計
| 封裝 | 針腳 | CAD 符號、佔位空間與 3D 模型 |
|---|---|---|
| VSSOP (DGS) | 10 | Ultra Librarian |
| SOIC (D) | 14 | Ultra Librarian |