Product Details
●The ADP5587 is an I/O port expander and keypad matrix designed for QWERTY type phones that require a large keypad matrix and expanded I/O lines. I/O expander ICs are used in mobile platforms as a solution to the limited number of GPIOs available in the main processor.
●In its small 4 mm × 4 mm package, the ADP5587 contains enough power to handle all key-scanning and decoding and to flag the processor of key presses and releases via the I2C interface and interrupt. The ADP5587 frees the main micro-processor from the need to monitor the keypad, thereby minimizing current drain and increasing processor bandwidth. The ADP5587 is also equipped with a buffer/FIFO and key event counter to handle and keep track of up to 10 unprocessed key or GPI events with overflow wrap and interrupt capability.
●The ADP5587 has keypad lock capability with an option to trigger or not trigger an interrupt at key presses and releases. All communication to the main processor is done using one interrupt line and two I2C-compatible interface lines. The ADP5587 can be configured as a keypad matrix of up to 8 rows × 10 columns (a maximum of 80 keys).
●When the ADP5587 is used for smaller keypad matrices, unused row and column pins can be reconfigured to act as general-purpose inputs or outputs. R0 to R7 denote the row pins of the matrix, whereas C0 to C9 denote the column pins. At power-up, all rows and columns default to GPIs and must be programmed to function as part of the keypad matrix or as GPOs.
●Applications
● Keypad and I/O expander designed for QWERTY type phones that require a large keypad matrix
●### Features and Benefits
● 18-GPIO port expander or 10 × 8 keypad matrix
● GPIOs configurable as GPIs, GPOs, and keypad rows or columns
● I2C interface with auto-increment
● 1.7 V to 3.6 V operation
● Keypad lock capability
● Open-drain interrupt output
● Key press and key release interrupts
● GPI interrupt with level programmability
● Programmable pull-ups
● Key event counter with overflow interrupt
● 275 μs debounce on the reset line and GPIs
● See data sheet for additional features
