LM3554是TI公司的一款相机闪光灯LED驱动器产品，LM3554是具有 1.2A 双路高侧 LED 驱动器和 I2C 兼容接口的同步升压转换器，本页介绍了LM3554的产品说明、应用、特性等，并给出了与LM3554相关的TI元器件型号供参考。
LM3554 - 具有 1.2A 双路高侧 LED 驱动器和 I2C 兼容接口的同步升压转换器 - 相机闪光灯LED驱动器 - LED驱动器 - TI公司（Texas Instruments，德州仪器）
The LM3554 is a 2MHz fixed frequency, current mode synchronous boost converter. The device is designed to operate as a dual 600mA (1.2A total) constant-current driver for high-current white LEDs, or as a regulated 4.5V or 5V voltage source.
The dual high-side current sources allow for grounded cathode LED operation. An adaptive regulation method ensures the current source for each LED remains in regulation and maximizes efficiency.
The main features include: an I2C-compatible interface for controlling the LED current or the desired output voltage, a hardware Flash enable input for direct triggering of the Flash pulse, and dual TX inputs which force the Flash pulse into a low-current Torch mode allowing for synchronization to RF power amplifier events or other high-current conditions. Additionally, an active high hardware enable (HWEN) input provides a hardware shutdown during system software failures.
Five protection features are available within the LM3554 including a software selectable input voltage monitor, an internal comparator for interfacing with an external temperature sensor, four selectable current limits to ensure the battery current is kept below a predetermined peak level, an over-voltage protection feature to limit the output voltage during LED open circuits, and an output short circuit protection which limits the output current during shorts to GND. Additionally, the device provides various fault indicators including: a thermal fault flag indicating the LED temperature has tripped the thermal threshold, a flag indicating a TX event has occurred, a flag indicating the flash timeout counter has expired, a flag indicating the devices die temperature has reached the thermal shutdown threshold, and a flag indicating an open or short LED.
- Dual High Side Current Sources
- Grounded Cathode Allowing for Better Heat Sinking and LED Routing
- >90% Efficiency
- Ultra-Small Solution Size: < 23mm2
- Four Operating Modes: Torch, Flash, LED Indicator and Voltage Output
- Accurate and Programmable LED Current from 37.5mA to 1.2A
- Programmable 4.5V or 5.0V Constant Output Voltage
- Hardware Flash and Torch Enable
- LED Thermal Sensing and Current Scaleback
- Software Selectable Input Voltage Monitor
- Programmable Flash Timeout
- Dual Synchronization Inputs for RF Power Amplifier Pulse Events
- Open and Short LED Detection
- Active High Hardware Enable for Protection Against System Faults
- 400kHz I2C-Compatible Interface
- 16-Bump (1.7mm × 1.7mm × 0.6mm) DSBGA
