ADP5588

Data Sheet FEATURES 18-GPIO port expander or 10 × 8 keypad matrix GPIOs configurable to GPIs, GPOs, and keypad rows or columns Dual light sensor inputs (C8 and C9) I2C interface I2C register read autoincrement 1.8 V to 3.0 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 50 μs debounce on the reset line and GPIs 1 μA typical idle current, 55 μA typical polling current drain for one key press Small 4 mm × 4 mm LFCSP package APPLICATIONS Keypad and I/O expander designed for QWERTY type phones that require a large keypad matrix GENERAL DESCRIPTION The ADP5588 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 ADP5588 contains enough power to handle all key scanning and decoding and flag the processor of key presses and releases via the I2C® interface and interrupt. It frees the main microprocessor from having to monitor the keypad, thereby minimizing current drain and increasing processor bandwidth. It 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 ADP5588 has a...