Keypad controllers support QWERTY
The GPIO/keypad controllers can also save battery life in portable devices, as they consume less than 30µA (typical) when keys are pressed and less than 1µA (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).
They 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.
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