A five-channel output expander from Texas Instruments is claimed to be the industry's smallest. The TCA5405 reduces required connections by up to 75% with self-timed, single-wire technology. It can be used by system designers to control and expand outputs to as many as five, using a single processor GPIO. As well as reducing the number of connections needed, eliminating 50% of the lines versus I2C, and 75% compared to an SPI (serial peripheral interface) bus. This device can be implemented in designs that require a small footprint, such as mobile phones, PDAs, portable media players, and portable instrumentation devices such as blood glucose meters and insulin pumps. The one-wire protocol-based port expansion is in an eight-pin, 2.25mm2 micro-QFN package makes it the industry's smallest five-channel expander, says the company.
