AAT1270

Application

• Camcorder Video Light (Torch Light)
• Cellphones / Smartphones
• Digital Still Cameras (DSC)
• LED Photo Flash Light (Strobe Light)
• Mobile Handsets
• MP3 Players
• PDAs and Notebook P




Pinout






Specifications

• Input Voltage Range: 2.7V to 5.5V
• Dual Channel Output
  • Up to 1A Regulated Output Current (0.5A per Channel)
• Up to 85% Efficiency with Small Magnetics
• 2 MHz Switching Frequency
• Separate Flash Enable Input
• Separate Flash Inhibit Input
• Single Resistor Sets Flash and Movie Mode Current
  • Fixed Flash-to-Movie Mode Current Ratio
• 16-Level Movie Mode Current via S2Cwire™
• User-Programmable Safety Timer
• True Load Disconnect
• Input Current Limit
• Over-Voltage (Open LED, Open Circuit), Short-Circuit, and Over-Temperature Protection
• Shutdown Current: < 1.0µA
• Small Inductor Solution: 1µH (0.9mm in height)
• 14-pin STDFN/TDFN 3x3mm package
• -40 to +85C Temperature Range

Symbol	Description	Value	Units
IN, SW, OUT	Maximum Rating	-0.3 to 6.0	V
RSET, EN/SET, FLEN, FLINH, CT,LOUTA, FLOUTB	Maximum Rating	VIN + 0.3	V
TJ	Operating Temperature Range	-40 to 150	°C
TS	Storage Temperature Range	-65 to 150	°C
TLEAD	Maximum Soldering Temperature (at leads, 10 sec)	300	°C

Description

span id="lblDescription">The AAT1270 is a high-efficiency, high-current boost converter capable of 1A maximum output current. It is an ideal power solution for high brightness LED or LED photo flash applications in all single-cell Lithium-ion / polymer battery operated products.

The AAT1270 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 AAT1270 ideally suited for small battery-powered applications. AnalogicTech proprietary S2Cwire™ (Simple Serial Control™) serial digital interface is used to enable, disable and set the movie mode current level for the flash LEDs to one of 16 levels. The AAT1270 also includes a separate Flash Enable input to initiate both flash/strobe operation and the default timer, which can be used to terminate a flash event after a user programmed delay or as a safety feature. A Flash Inhibit pin is also included which reduces flash current to movie mode level during high battery demand.

The maximum flash and movie mode current is set by one external resistor; the ratio between flash and movie mode current is set at approximately 7.3:1. One or two LEDs can be connected to the AAT1270; when two LEDs are used, the output current is matched between each diode.

The AAT1270 contains over-voltage protection and a thermal management system to protect the device in the event of an output open-circuit and short-circuit condition respectively. Built-in circuitry prevents excessive inrush current during start-up. The shutdown feature reduces quiescent current to less than 1.0µA.

The AAT1270 is a high-efficiency, high-current boost converter capable of 1A maximum output current. It is an ideal power solution for LED photo flash applications in all single-cell Lithium-ion / polymer battery operated products.

The AAT1270 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 AAT1270 ideally suited for small battery-powered applications.

AnalogicTech's proprietary S2Cwire™ (Simple Serial Control™) serial digital interface is used to enable, disable and set the movie mode current level for the flash LEDs to one of 16 levels. The AAT1270 also includes a separate Flash Enable input to initiate both flash/strobe operation and the default timer, which can be used to terminate a flash event after a userprogrammed delay or as a safety feature. A Flash Inhibit pin is also included which reduces flash current to movie mode level during high battery demand.

The maximum flash and movie mode current is set by one external resistor; the ratio between flash and movie mode current is set at approximately 7.3:1. One or two LEDs can be connected to the AAT1270; when two LEDs are used, the output current is matched between each diode.

The AAT1270 contains over-voltage protection and a thermal management system to protect the device in the event of an output open-circuit and short-circuit condition respectively. Built-in circuitry prevents excessive inrush current during start-up. The shutdown feature reduces quiescent current to less than 1.0A.