LP8557 用于平板电脑的 LP8557 高效率 LED 背光驱动器 | 德州仪器 TI.com.cn

LP8557
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用于平板电脑的 LP8557 高效率 LED 背光驱动器

用于平板电脑的 LP8557 高效率 LED 背光驱动器 - LP8557
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备选器件推荐

  • LP8556  - 器件与被比较器件具有相同的功能,但并不是引脚对引脚等效,也有可能参数不相同。   Recommended for designs which require 2 or 3 cells versus the LP8557 is recommended for 1 cell designs.
  • TPS61176  - 器件与被比较器件具有相同的功能,但并不是引脚对引脚等效,也有可能参数不相同。   TPS61176 offers similar basic functionality on QFN Package

描述

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.

特性

  • 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

参数

与其它产品相比 背光LED驱动器 邮件 下载到电子表格中
Part number 立即下单 Channels (#) Vin (Min) (V) Vin (Max) (V) Vout (Min) (V) Vout (Max) (V) Switching frequency (Max) (kHz) Type LED current per channel (mA) LED (#) Topology Shutdown current (Typ) (uA) Peak efficiency (%) LED configuration Function Features Operating temperature range (C) Package Group Package size: mm2:W x L (PKG)
LP8557 立即下单 6     2.7     5.5     7     28     1000     Inductive     25     48     Boost     0.001     93     6 LED channels
Parallel    
  CABC
Edge Rate Control    
-30 to 85     DSBGA | 16     See datasheet (DSBGA)    
LM36274 立即下单 4     2.7     5     27     30     1050     Inductive     30     32     Boost
Current Sink    
1.2     92     Parallel
Series    
  Adjustable Switch Frequency
CABC
I2C Control
OVP
Thermal Shutdown    
-40 to 85     DSBGA | 24     See datasheet (DSBGA)    
LM36923H 立即下单 3     2.5     5.5     0     37     1050     Inductive     30     30     Boost
Current Sink
Multi-Channel    
1.2     92     Parallel
Series    
  Adjustable Switch Frequency
CABC
Direct PWM Dimming
Enable/Shutdown
I2C Control
OVP
Thermal Shutdown    
-40 to 85     DSBGA | 12     12DSBGA: 2 mm2: 1.16 x 2 (DSBGA | 12)    
LP8553 立即下单 4     2.7     22     10     40     1250     Inductive     50     40     Boost     1     93         PWM Control     -30 to 85     DSBGA | 25     25DSBGA: 8 mm2: 2.8 x 3 (DSBGA | 25)    
LP8555 立即下单 12     2.7     20     7     28     1000     Inductive     50     96     Boost     3