Design and Implementation of a Configurable I/O Expander with the Wide-range Voltage and Temperature

I/O expander is a popular device in embedded systems, often serving as system adhesive. It is commonly based on I2C to support bi-directional communication between multiple interconnected devices in a master-slave structure. After analyzing some products in the market, we have proposed a configurable I/O expander with the wide-range voltage and temperature. It consists of communication block, control block, interrupt block, and IO block. At the same time, we propose the ultra-low voltage design methodology to be compatible with as many devices as possible. In addition, we also insert BIST circuit to improve reliability and yield. After a series of simulation, the proposed design was fabricated in 0.35$\mu$m CMOS process, and the test on chip level is carried out after tape-out. The results show that the I/O expander has better performance and faster response compared with other works, which is very suitable for end-side devices in the IOT and servers.