AAT1278

1.5A Single Flash LED Driver


Please note: this product is being discontinued and is not recommended for new designs.

The AAT1278 is a high-efficiency, 1.5A high-current boost converter for LED photo flash applications. It maintains output current regulation by switching the internal high-side and low-side switch transistors, pulsewidth modulated at a fixed frequency of 2MHz. The high switching frequency allows the use of a small external inductor and output capacitor, making the AAT1278 ideally suited in all single cell, Li-ion-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 AAT1278. Using the AS2Cwire interface, the movie-mode current level for each LED, and the flash-to-movie-mode current ratio can be programmed to one of 16 levels. The AAT1278 includes a separate Flash Enable input to initiate the flash operation and 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. The AAT1278 can drive one high current LED. The AAT1278 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 AAT1278 is available in a Pb-free, thermally-enhanced CSP-12 package and operates over the -40°C to 85°C temperature range.

Please note: AAT1278 is being discontinued and is not recommended for new designs.

Specifications

Flash IOUT Total (mA)1500
Movie Mode IOUT Total (mA)206
LED Channels1
Min. VIN (V)2.7
Max. VIN (V)5.5
Max. VOUT (V)5.5
InterfaceAS2Cwire™
Max. Shutdown Current (μA)1
Typ. IQ (μA)230
Peak Efficiency88%
Package
Package (mm)
PackageWLCSP-12

Features

  • Input Voltage Range: 2.7V to 5.5V
  • Single Channel Flash Output
  • Up to 1.5A Regulated Output Current
  • Up to 88% Efficiency
  • 2 MHz Switching Frequency
  • Separate Flash Enable
  • Single Resistor Sets Flash and Movie Mode Current
  • AS2Cwire Single Wire Programming:
  • Movie Mode Current
  • Flash/Movie Mode Current Ratio
  • True Load Disconnect
  • Soft-Start and Input Current Limit
  • Over-Voltage (Open LED, Open Circuit), Short Circuit,and Over-Temperature Protection
  • -40°C to +85°C Temperature Range

Product Documents