Description

The Allegro®A8740 is a Xenon photoflash charger IC designed to meet the needs of ultra low power, small form factor cameras, particularly camera phones. By using primary-side voltage sensing, the need for a secondary-side resistive voltage divider is eliminated. This has the additional benefit of reducing leakage currents on the secondary side of the transformer. To extend battery life, the A8740 features very low supply current draw (0.5 μA max in shutdown mode). The IGBT driver also has internal gate resistors for minimum external component count. The charge and trigger voltage logic thresholds are set at 1.3 VHI(min) to support applications implementing low-voltage control logic.

Features and Benefits

▪ Ultra small 2 × 2 DFN/MLP-8 package

▪ Low quiescent current draw (0.5 μA max. in shutdown mode)

▪ Primary-side output voltage sensing; no resistor divider required

▪ Fixed 1.5 A peak current limit

▪ 1.3 V logic (VHI(min)) compatibility

▪ Integrated IGBT driver with internal gate resistors

▪ Optimized for mobile phone, 1-cell Li+ battery applications

▪ Zero-voltage switching for lower loss

▪ >75 efficiency

▪ Charge complete indication

▪ Integrated 50 V DMOS switch with self-clamping protection

A8740属于集成电路（IC） > LED 驱动器。Allegro MicroSystems制造生产的A8740LED 驱动器器件属于 LED 驱动器电源管理集成电路 (PMIC) 系列，可通过标称固定电压的电源为负载（通常为发光二极管）提供电流，并且电流可控。它与用于电压调节的类似产品的主要区别在于，这类器件提供较低的反馈电压（以提高系统能效），而且通常可对器件工作点进行外部控制，可在照明应用中用于实现调光功能。