TI LP55231 评估参考设计方案

TI公司的LP55231是一款应用于照明效果移动设备的9通道LED驱动芯片，内部集成高效电荷泵以驱动高于锂电池供电的LED设备，该芯片内部集成程序存储器，允许在没有微控制器的情况下进行操作。本文首先介绍芯片的简介、特性、内部框图及应用领域，并给出相应设计方案的设计原理图、元器件列表及制板图。
The LP55231 is a 9-channel LED driver designed to produce lighting effects for mobile devices. A high-efficiency charge pump enables LED driving over full Li-Ion battery voltage range. The device is equipped with an internal program memory, which allows operation without processor control.
The LP55231 maintains excellent efficiency over a wide operating range by autonomously selecting the best charge pump gain based on LED forward voltage requirements. The device is able to automatically enter power-save mode when LED outputs are not active, thus lowering idle current consumption down to 10 μA (typ).
LP55231主要特性：
• Three Independent Program Execution Engines, 9 Programmable Outputs With 25.5mA Full-scale Current, 8-bit Current Setting Resolution and 12-bit PWM Control Resolution
• Adaptive High-efficiency 1x/1.5x Fractional Charge Pump - Efficiency up to 94%
• LED Drive Efficiency Up to 93%
• Charge Pump With Soft Start and Over-current/Short-circuit Protection
• Built-in LED Test
• 200 nA Typical Standby Current
• Automatic Power Save Mode; IVDD = 10 μA (Typ.)
• Two-wire I2C-compatible Control Interface
• Flexible Instruction Set
• Large SRAM Program Memory
• Small Application Circuit
• Source (High-side) Drivers
• Architecture Supports Color Control
LP55231应用：
• Fun Lights and Indicator Lights
• LED Backlighting
• Haptic Feedback
• Programmable Current Source
 
图1. LP55231内部方框图
LP55231方案介绍：
The LP55231 provides flexibility and programmability for dimming and sequencing control. Ea...