Unterpremstaetten, Austria (February 28, 2012) – A new smart LED driver IC, the AS3668 introduced by austriamicrosystems (SIX: AMS), a leading global designer and manufacturer of high performance analog ICs, controls up to four LEDs to produce sophisticated indicator lighting effects in mobile phones and tablets without requiring the intervention of the power-hungry baseband processor.
It can also be used in many other consumer electronics devices such as 3G and LTE modems, USB memory sticks, game controllers and headsets in which indicator lighting can enhance the user interface, and in which high-value light effects and low power consumption are required.
The AS3668’s attractive lighting effects enhance the appearance and perceived value of a mobile device and act as an additional user interface. Its 12-bit PWM dimming function enables, for instance, a smooth “breath light” effect with visually seamless transitions between lower and higher brightness levels. The IC also has an audio synchronization mode in which the LED changes brightness and color in response to audio content.
The baseband-independent solution provided by the AS3668 means that light patterns – for instance to indicate to the phone or tablet user that they have missed calls or unread text messages, or that an incoming call is waiting – can be continually produced while the baseband stays in its lowest-power ‘deep sleep’ mode.
System power consumption for LED indicator lights driven by the AS3668 is therefore much lower than in conventional implementations using a simple transistor arrangement controlled by the baseband. These conventional designs require the baseband to be activated each time an LED requires input current, and this drains the phone’s battery quickly because the baseband consumes large amounts of power when in active mode.
The AS3668 is a highly efficient charge pump-based programmable LED driver IC. It provides accurate current sources of up to 25 mA for each LED, enabling the generation of a choice of light colors when used with an RGB/W (red, green, blue and white) cluster of LEDs.
The device draws just 0.2 µA typical in stand-by mode. A programmable VBAT monitor offers fail-safe operation in all system environments, and an automatic start-up pattern can be enabled to indicate to the user that the mobile device is connected to a charger, even if the battery has too little power for the baseband to wake up and start the system.
The IC provides a choice of light patterns, rise and fall timing, pause, pulse-skip, color variations and audio synchronization. Implementation in a target system is facilitated by a simple programming interface; only a few commands are required to program the device. Once in the system, the various functions can be represented in the user interface, and can therefore enable user adjustment of light patterns and colors.
The AS3668 smart LED driver is available in a miniature 1.26 mm x 1.68 mm 12-pin WL-CSP package. It is in volume production, priced at $0.73 in 1,000 piece quantities.
For more information on the AS3668 LED driver please visit www.austriamicrosystems.com/LED-driver/AS3668.
About austriamicrosystems
austriamicrosystems is a leading designer and manufacturer of high performance analog ICs, combining 30 years of analog design know-how with state-of-the-art manufacturing and test facilities and production partnerships. austriamicrosystems leverages its expertise in low power and high accuracy to provide industry-leading standard and customized analog products. Operating worldwide with more than 1,200 employees, austriamicrosystems focuses on the areas of power management, sensors & sensor interfaces and mobile infotainment in its markets Consumer & Communications, Industry & Medical and Automotive. Through the acquisition of TAOS, a world leader in advanced light sensors, austriamicrosystems has expanded its innovative sensor offering for growth markets such as mobile devices. austriamicrosystems is listed on the SIX Swiss Exchange in Zurich (ticker: AMS). For more information, please visit www.austriamicrosystems.com
