Programmable Low-Power GPIO/Keypad Controllers



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Analog Devices, Inc. (ADI), a global leader in high-performance semiconductors for signal processing applications, introduced today the ADP5585 and ADP5589 GPIO (general-purpose input/output) port expander and keypad matrix controller for devices that require expanded I/O lines or mechanical keypads up to QWERTY size. The new GPIO/keypad controllers feature the industry's lowest active current drain and integrated programmable logic/PWM (pulse-width modulator) in the smallest available package. These GPIO/keypad controllers save battery life in portable devices by consuming less than 30 μA (typical) when keys are pressed and less than 1 uA (typical) when the keys are idle. The ADP5585 and ADP5589 simplify interface connectors by saving up to 10 I/O lines (ADP5585) and 19 I/O lines (ADP5589) to the main processor. Both keypad controllers support multiple, simultaneous key press detection and communicate presses and releases in a chronological order via a 16-byte FIFO. In addition to the built-in programmable logic devices, two programmable reset generators allow designers to program keys, GPIOs, and/or logic changes to generate a reset signal to restart a locked up processor. Both devices are available in small LFCSP (ADP5585: 3.0 mm x 3.0 mm; ADP5589: 3.5 mm x 3.5 mm) and WLCSP packages (ADP5585: 1.59 mm x 1.59 mm; ADP5589: 1.99 mm x 1.99 mm).

The ADP5585 and ADP5589 are designed for devices with front-panel keypads that need to expand the number of GPIO ports without increasing pin count. Both devices free up the main processor from having to monitor the keypad, thereby reducing power consumption and increasing processor bandwidth for other functions. The new controllers handle all key scanning and decoding functions and use an interrupt line to flag the main processor when new key events have occurred. Both the ADP5585 and ADP5589 are equipped with FIFO registers that store up to 16 events which are then read back by the processor through an I2C -compatible interface. Evaluation boards and Linux software drivers are available to provide the necessary tools to implement new designs quickly and efficiently. Key Features of the ADP5585 and ADP5589 GPIO/Keypad Controllers
  • Lower power consumption of 30 μA (typical) with keypad active, compared to 54 μA to 1000 μA available through alternative GPIO/keypad controllers
  • 16-event FIFO simplifies reading of key, GPIO, and logic changes
  • 10 configurable GPIO ports capable up to 30 keys can save up to 10 I/O lines to the main processor, simplifying interconnects (ADP5585)
  • 19 configurable GPIO ports capable up to 96 keys can save up to 19 I/O lines to the main processor, simplifying interconnects (ADP5589)
  • I2C interface with Fast-mode Plus (Fm+) supports data rates up to 1 Mbps
About Analog Devices Innovation, performance, and excellence are the cultural pillars on which Analog Devices has built one of the most long-standing, high-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 electronics equipment. Celebrating over 40 years as a leading global manufacturer of high-performance integrated circuits used in analog and digital signal processing applications, Analog Devices, Inc. is headquartered in Norwood, Massachusetts, with design and manufacturing facilities throughout the world. It has manufacturing facilities in Massachusetts, California, North Carolina, Ireland, and the Philippines. Analog Devices' common stock is listed on the New York Stock Exchange under the ticker "ADI" and is included in the S&P 500 Index. About Analog Devices in Europe In Europe, Analog Devices accounts for about one fifth of the company's worldwide revenues and worldwide work force. The company has a manufacturing facility in Limerick, Ireland, and design and development centres in Denmark, England, Finland, Scotland, Slovakia, Spain and Ireland. European client references include main telecom equipment manufacturers Alcatel, Ericsson and Nokia-Siemens Networks, automotive systems manufacturers such as Autoliv, Bosch and Continental, consumer references such as Harman and Philips, and a variety of industrial clients including ABB, Agilent Technologies, Siemens and Rohde & Schwarz.