LP8557
- High-Efficiency DC-DC Boost Converter With 28-V Integrated Power MOSFET
- 2.7-V to 5.5-V VDD Range for Supporting Single-Cell Li-Ion Battery Applications
- Six 25-mA High-Precision LED Current Sinks
- Adaptive Boost Voltage and LED Current Sink Headroom Controls for Maximum System Efficiency
- LED String Count Auto-Detect for Maximum Design Flexibility
- Smart Phase Shift PWM Mode for Reduced Audible Noise
- PWM Input Duty Cycle Brightness Control, PWM Output Frequency Selectable Independent of Input Frequency
- Hybrid PWM Plus Current Dimming for Higher LED Drive Optical Efficiency
- Switching Frequency, PWM Output Frequency, and LED Current can be set Through Resistors or I2C Interface
- Programmable Boost SW Slew Rate Control and Spread Spectrum Scheme for Reduced Switching Noise and Improved EMI Performance
- UVLO, TSD, BST_OVP, BST_OCP, BST_UV, LED OPEN* and LED Short Fault Coverage
- Minimum Number of External Components
The LP8557 and LP8557I are high-efficiency LED drivers each featuring an integrated DC-DC inductive boost converter and six high-precision current sinks. LP8557 is intended for applications that exclusively use a pulse width modulated (PWM) signal for controlling the brightness while LP8557I is intended for applications that can utilize an I2C master as well.
The boost converter has adaptive output voltage control. This feature minimizes the power consumption by adjusting the voltage to the lowest sufficient level under all conditions.
The adaptive current sink headroom voltage control scales the headroom voltage with the LED current for optimal system efficiency.
The LED string auto-detect function enables use of the same device in systems with 1 to 6 LED strings for the maximum design flexibility.
Proprietary hybrid PWM plus current mode dimming enables additional system power savings. Phase-shift PWM allows reduced audible noise and smaller boost output capacitors.
Flexible CABC support combines brightness level selections based on the PWM input and I2C commands.
For all available packages, see the orderable addendum at the end of the data sheet.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 | LP8557 High-Efficiency LED Backlight Driver For Tablets datasheet (Rev. B) | PDF | HTML | 2015/12/18 | ||
| 白皮書 | Common LED Functions and LED Driver Design Considerations | 2020/9/21 | ||||
| 應用說明 | Some Guidelines and Tips for the LED Driver Application | 2019/8/14 | ||||
| 應用說明 | Inductor Selection in Boost Converters for LCD Backlight Applications | 2016/10/24 | ||||
| 應用說明 | Schottky Diode Selection in Asynchronous Boost Converters | 2016/9/6 |
設計與開發
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LP8557EVM — 適用於 LP8557 6 通道高效率 LCD 背光驅動器的評估模組
LP8557 6 通道高效率 LCD 背光驅動器評估套件。 LP8557 評估套件僅需要電源和 PWM 來源。 開機時，LED 亮度受到 PWM 訊號的脈衝寬度控制。
LP8557IEVM — 具有 I2C 控制，適用於 LP8557 高效率白光 LED 背光驅動器的評估模組
LP8557IEVM 是一款 6 通道高效率 LCD 背光驅動器評估套件，其中包括 I2C 相容程式以及具有迷你 USB 傳輸線的 USB2ANY 轉接器電路板，可透過簡單方式進行零件元件操作與測試。 裝置狀態受到評估軟體監控，並可探索各種配置。
LP8550SW-LINUX — 適用於 LP8550 的 Linux 驅動程式
The Linux driver supports the LP8550/1/2/3/5/6 and LP8557. The Linux driver supports communication through the I2C bus and interfaces with the backlight and PWM sub-system.
Linux Mainline Status
Available in Linux Main line: Yes
Available through git.ti.com: N/A
Supported Devices:
- lp8550
- lp8551
- lp8552
- (...)
SNVC125 — LP8557 evaluation program
| 封裝 | 針腳 | CAD 符號、佔位空間與 3D 模型 |
|---|---|---|
| DSBGA (YFQ) | 16 | Ultra Librarian |