LM3550是TI公司的一款相机闪光灯LED驱动器产品，LM3550是具有自动 Vf 和 ESR 检测的闪存 LED 驱动器，用于移动摄像机系统，本页介绍了LM3550的产品说明、应用、特性等，并给出了与LM3550相关的TI元器件型号供参考。
LM3550 - 具有自动 Vf 和 ESR 检测的闪存 LED 驱动器，用于移动摄像机系统 - 相机闪光灯LED驱动器 - LED驱动器 - TI公司（Texas Instruments，德州仪器）
LM3550 is a low-noise, switched-capacitor DC/DC converter designed to operate as a current-limited and adjustable (up to 5.3V) super-capacitor charger. LM3550 features user-selectable super-capacitor charge-termination voltages and an optimal charge-termination mode that maximizes flash-energy efficiency by accounting for flash element losses. Additionally, the device provides one adjustable constant current output (up to 200 mA) and one NFET controller ideal for driving one or more high-current LEDs either in a high-power flash mode or a low-power torch mode.
The LM3550 can be configured to utilize a proprietary super-capacitor charging scheme (Optimal Charge Mode), allowing faster charging times (0 to Target Voltage) and lower current-source power dissipation. Optimal Charge Mode adapts to changes in the flash LEDs forward voltage as well as the super-capacitor's ESR ensuring that the super-capacitor is charged to the ideal voltage required to sustain constant current-flash operation.
The LED current and Flash pulse duration of the LM3550 can be programmed via an I2C-compatible interface. The STROBE pin allows the Flash to be toggled via a flash-enable signal from a camera module. The EOC pin sinks current when the output voltage reaches 95% of the final value.
The ALD/TEMP input pin allows either a light sensor to adjust the flash-current level based on the ambient light conditions, or it allows for over-temperature detection and protection of the LED during high-power operation or high ambient-temperature conditions by connecting an NTC thermistor temperature monitoring circuit to the pin.
- Up to 5A Flash Current
- 4 Selectable Super-Capacitor Charge Voltage Levels (4.5V, 5.0V, 5.3V, Optimized)
- Flash Optimized Charge Mode for Optimal Efficiency
- 33% Faster Charge Time Using Optimal Mode
- 49% Less Power Dissipated in Current Source using Optimal Charge Mode
- Fast Super-Capacitor Charger with 500 mA Input Current Limit
- Adjustable Torch Current (60 mA to 200 mA)
- Ambient Light or LED Thermal Sensing with Current Scaleback
- End-of-Charge Output (EOC)
- Dedicated Indicator LED Current Source
- No Inductor Required
- Manual Flash Enable via Strobe Pin Input
- Programmable Flash Pulse Duration, and Torch and Flash Currents via I2C-compatible Interface
- True Shutdown (LED Disconnect)
- Flash Time-Out Protection
- LED Temperature Protection or Ambient Light Sensing Pin
- Low Profile 20-Pin UQFN Package (3.0 mm × 2.5 mm × 0.8 mm)
