General Description
The AAT1239-1 is a high frequency, high efficiency constant current boost converter capable of driving up to ten (10) series-connected white LEDs or 40V. It is an ideal power solutions for backlight applications with up to ten white LEDs in series. The input voltage is 2.7V to 5.5V for single-cell lithium-ion/polymer (Li-ion) based portable devices.
The LED current is digitally controlled across a 6x operating range using AnalogicTech’s Simple Serial Control™ (S2Cwire™) interface. Programmability across 26 discrete current steps provides high resolution, low noise, flicker-free, constant LED outputs. In programming AAT1239 operation, LED brightness increases based on the data applied at the EN/SET pin. The SEL logic pin changes the feedback voltage between two programmable ranges.
The AAT1239-1 features a high current limit and fast, stable transitions for stepped or pulsed current applications. The high switching frequency (up to 2MHz) provides fast response and allows the use of ultra-small external components, including chip inductors and capacitors. Fully integrated control circuitry simplifies design and reduces total solution size. The AAT1239-1 offers a true load disconnect feature which isolates the load from the power source while in the OFF or disabled state. This eliminates leakage current, making the devices ideally suited for battery-powered applications.
The AAT1239-1 is available in the Pb-free, thermallyenhanced 12-pin TSOPJW package.

*Input Voltage Range: 2.7V to 5.5V
*Maximum Continuous Output 40V @ 30mA
*Drives up to 10 LEDs in Series
-Constant LED Current with 3.5% Accuracy Over Temperature and Input Voltage Range
*Digital Control with S2Cwire Single Wire Interface
-26 Discrete Steps
-No PWM Control Required
-No Additional Circuitry
*Up to 85% Efficiency
*Up to 2MHz Switching Frequency Allows Small External Chip Inductor and Capacitors
*Hysteretic Control
-No External Compensation Components
-Excellent Load Transient Response
-High Efficiency at Light Loads
*Integrated Soft Start with No External Capacitor
*True Load Disconnect Guarantees <1.0μA Shutdown Current
*Selectable Feedback Voltage Ranges for High Resolution Control of Load Current
*Short-Circuit, Over-Voltage, and Over-Temperature Protection
*12-Pin TSOPJW Package
*-40°C to +85°C Temperature Range

*Color Display Backlight
*Digital Still Cameras (DSCs)
*Digital Photo Frames
*PDAs and Notebook PCs
*White LED Drivers


Trackback ::

댓글을 달아 주세요 Comment