描述 Description

The AAT1272 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 AAT1272 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 AAT1272 ideally suited for small battery-powered applications.
An industry-standard I2C serial digital input is used to enable, disable and set the movie-mode current for each flash LED with up to 16 movie-mode settings. The AAT1272 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 user-programmed delay or as a safety feature. The maximum flash and movie-mode current is set by one external resistor; the ratio of Flash to Movie-mode current is set at approximately 7.3:1. One or two LEDs can be connected to the AAT1272; in the case of two LEDs the output current is matched between each diode.
The AAT1272 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 AAT1272 is available in a Pb-free, thermally-enhanced 14-pin 3x3mm TDFN package.

特性 Features

·VIN Range: 2.7V to 5.5V
·Dual Channel Output
·Up to 1.5A Regulated Output Current (750mA per
·channel)
·Up to 85% Efficiency with Small Inductor (1μH)
·2 MHz Switching Frequency
·Separate Flash Enable
·User-Programmable Safety Timer
·Single Resistor Sets Flash and Movie Mode Current
·Two Wire, I2C Compliant Serial Interface
·Fast, 400kHz Serial Transfer Rate
·16 Level Movie-mode Current
·Flash/Movie-mode
·Current Output Channel Control
·Safety Timer
·True Load Disconnect
·Input Current Limit
·Over-Voltage (Open LED, Open Circuit), Short Circuit, and Over-Temperature Protection
·Shutdown Current < 1.0μA
·14-pin TDFN 3x3 mm Package
·-40°C to +85°C Temperature Range

簡介

AAT1272屬于集成電路（IC）的LED驅(qū)動器。由制造生產(chǎn)的AAT1272LED 驅(qū)動器器件屬于 LED 驅(qū)動器電源管理集成電路 (PMIC) 系列，可通過標稱固定電壓的電源為負載（通常為發(fā)光二極管）提供電流，并且電流可控。它與用于電壓調(diào)節(jié)的類似產(chǎn)品的主要區(qū)別在于，這類器件提供較低的反饋電壓（以提高系統(tǒng)能效），而且通?？蓪ζ骷ぷ鼽c進行外部控制，可在照明應用中用于實現(xiàn)調(diào)光功能。