MOBILE I/O EXPANDER AND QWERTY KEYPAD CONTROLLER ENABLES UP TO 50 PERCENT LONGER BATTERY LIFE FOR PORTABLE ELECTRONICS

- ADI’s ADP5588 integrates general purpose I/O expansion for mobile processors, QWERTY keypad control, and ambient-light sensing for backlight management in portable devices.

Norwood, MA (05/12/2009) - Analog Devices, Inc. (ADI), a global leader in high-performance semiconductors for signal-processing applications has announced the ADP5588 mobile I/O expander and QWERTY keypad controller with ambient light sensing for smart portable devices that require a large keypad matrix and expanded I/O lines. The ADP5588 integrates keypad scanning, de-bouncing and interrupt generation, resulting in reduced processor I/Os and loading. The new mobile I/O expander also detects ambient-light conditions, information the processor can use to ensure efficient control of keypad backlighting, resulting in a significant reduction in overall power consumption that can extend battery life by 20 to 50 percent, depending on the usage model.

Efficient Performance through Integrated Design
Similar to its sister devices, the ADP5520 and ADP5501 adaptive lighting management systems, the ADP5588 features intelligent lighting control, which allows the device to automatically sense ambient light levels and adjust backlight brightness according to changing lighting environments, resulting in the optimum viewing conditions for the user. The integrated architecture saves energy by minimizing the required CPU processing for backlight-monitoring functions, reducing current drain on the battery, and increasing available processor bandwidth. As a result, the device can achieve a 20- to 50-percent increase in operating time, depending on the usage model.

Today’s baseband or applications processors are often I/O limited due to the ever-increasing functions smart portable devices provide. The ADP5588 mobile I/O expander enables the processor to control up to an additional 15 general purpose I/Os through the I2C-compatible bus, reducing direct processor routing from 18 lines to three.

For greater flexibility, the CPU can communicate to the ADP5588 through the I2C-compatible serial interface to reconfigure the row and column pins as general-purpose input, general-purpose output, or light-sensor input pins depending on the application. For example, the CPU can configure the port expander’s pins as an 8 x 10 keypad matrix with 80 keys (maximum) for devices that require additional key scan functionality. Alternatively, when working with smaller keypad matrices, unused matrix interface pins can serve as general-purpose I/Os or as light-sensor inputs.

The ADP5588 mobile I/O expander offloads key-scan and GPIO functions from the CPU, freeing up the processor for higher priority functions and saving energy. A key event counter with overflow interrupt capability allows the device to manage up to ten unprocessed key events, while a key-lock option allows designers to choose whether or not to issue a key-press interrupt when the lock is active. The ADP5588 manages all mobile key scanning and decoding functions by storing the key presses and releases, and flagging them to the processor via a single interrupt line and two I2C-compatible interface lines. This enables designers of QWERTY-based portable devices to minimize the number of control lines from the microprocessor, resulting in significant cost and reliability benefits.

Availability and Pricing
Samples of the ADP5588 mobile I/O expander are available now in 4 mm x 4 mm, 24-pin LFCSP (lead-frame chip-scale package) packaging. The device supports 1.8- to 3-V I/O operation. The ADP5588 costs $1.08 per unit in 1,000-unit quantities. For more information, visit www.analog.com/pr/ADP5588. For more information on ADI’s power-management products for display and lighting, visit http://www.analog.com/pr/DisplayandLighting.

ADI in Power Management
Analog Devices brings world-class signal-processing prowess to a portfolio of innovative power-management ICs that complement high-performance signal-processing functions in a wide range of portable and fixed-power applications in consumer electronics, medical equipment, industrial and instrumentation, and communications infrastructure. By supporting signal-chain design requirements, such as dynamic range, transient performance, and reliability, ADI helps customers solve complex power challenges easily and quickly, differentiate their products, and get to market faster. Learn more about ADI's power-management ICs at http://www.analog.com/power.

About Analog Devices

Innovation, performance, and excellence are the cultural pillars on which Analog Devices has built one of the longest standing, highest growth companies within the technology sector. Acknowledged industry-wide as the world leader in data conversion and signal conditioning technology, Analog Devices serves over 60,000 customers, representing virtually all types of electronic equipment. Analog Devices is headquartered in Norwood, Massachusetts, with design and manufacturing facilities throughout the world. Analog Devices is included in the S&P 500 Index.

Editor's Contact Information:

Howard Wisniowski
781/937-1517

howard.wisniowski@analog.com

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