AnalogicTech Launches Small, Quiet, Serial, Step-Up LED Backlight Drivers for Handheld Devices
The AAT14XX family enables larger displays, allows higher efficiencies and offers filtered pulse-width modulation (PWM) dimming to eliminate interference with the radios in cell phones and other handheld devices. With a 1.15 x 1.55 mm wafer-level chip scale package (WLCSP) size, the devices require only 0.7 cm(2) of space on a printed circuit board, making them one of the smallest solutions available.
"The requirements and features for optimal backlight power management are constantly evolving in tandem with the growth of the LED market," said Roger Smullen, Director, Strategic Marketing at AnalogicTech. "The AAT14XX family brings to market one of the smallest solutions for serial LED drivers, strengthening our portfolio for handheld devices. These new products add new capabilities to our comprehensive LED offerings, which are rapidly encompassing a broad range of end products ranging from handheld devices to tablets to televisions."
LED brightness is controlled in one of three ways: 32 dimming steps using the S(2)Cwire™ interface and filtered or direct PWM control. PWM dimming frequency of 100 KHz eliminates audible noise and is compatible with content adaptive brightness control (CABC) to further reduce backlight power consumption by up to 50 percent.
The major source of power drain in portable systems with displays is the backlight in a liquid crystal display (LCD) screen. The AAT14XX family addresses this with three dimming controls, and an integrated precision, high voltage current sink that provides maximum flexibility in adjusting LED current from 10 to 31 mA regardless of the number of series LEDs. This approach achieves a high efficiency of 88 percent, significantly more than that offered by traditional LED drivers that use a ballast resistor.