AAT1277 1.5A Step-Up Current Regulator for Flash LEDs
The AAT1277 is a high-efficiency, high-current boost converter capable of 1.5A typical output current. It is an ideal power solution for LED photo flash applications in all single cell Li-ion powered products. The AAT1277 maintains output current regulation by switching the internal high-side and low-side switch transistors. The transistor switches are pulse-width modulated at a fixed frequency of 2MHz. The high switching frequency allows the use of a small inductor and output capacitor, making the AAT1277 ideally suited for small battery-powered applications. Skyworks' proprietary AS2Cwire™ (Advanced Simple Serial Control™) serial digital interface is used to enable, disable, configure, and program the operation of the AAT1277. Using the AS2Cwire interface, the movie-mode current level for each LED, the safety timer delay, and the flash-to-movie-mode current ratio can be programmed to one of 16 levels. In addition, the single-wire serial protocol sets output channel control. The AAT1277 also includes a separate Flash Enable input to initiate both the flash operation and the default timer which can be used either to terminate a flash event at the end of a userprogrammed delay or as a safety feature. Also included is a Flash Inhibit pin which reduces the flash current to movie-mode levels during high battery demand. The maximum flash and movie-mode current is set by one external resistor where the ratio of Flash to Moviemode current is set at approximately 7.3:1. One or two LEDs can be connected to the AAT1277, where in the case of two LEDs the output current is matched between each diode. The AAT1277 contains a thermal management system to protect the device in the event of an output short-circuit condition. Built-in circuitry prevents excessive inrush current during start-up. The shutdown feature reduces quiescent current to less than 1.0μA. The AAT1277 is available in a Pb-free, thermally-enhanced 14-pin 3x3mm TDFN package.
技术特性
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应用领域 APPLICATION
订购信息 Ordering Information
AAT1277 典型应用
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| 应用技术支持与电子电路设计开发资源下载 | 版本信息 | 大小 |
| AAT1277 数据资料DataSheet下载:pdf | Rev.V2 | 2 页 |
