AAT1271 pdf datasheet (1.5A St

The AAT1271 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 AAT1271 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 AAT1271 ideally suited
for small battery-powered applications.
AnalogicTech’s proprietary AS2Cwire™ (Advanced Simple
Serial Control™) serial digital interface is used to enable,
disable, configure, and program the operation of the
AAT1271. 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 AAT1271 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 Movie-mode
current is set at approximately 7.3:1. One or two LEDs can
be connected to the AAT1271, where in the case of two
LEDs the output current is matched between each diode.
The AAT1271 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 AAT1271 is available in a Pb-free, thermally-enhanced
14-pin 3x3mm TDFN package.