I2C bus controller with a parallel port — what it bridges
The NXP PCF8584T/2,512 is an I2C bus controller that translates between a standard parallel microprocessor interface and the I2C serial bus. It handles all I2C bus timing and protocol, including clock generation, start/stop conditions, and arbitration, so the host processor only needs to read and write a few registers.
The 4.5V to 5.5V supply range ties this part to 5V logic families. It will not run from a 3.3V rail, so if your system has moved to lower voltages, you will need a level shifter or a separate 5V supply for this controller. The 1.5mA supply current is modest — fine for always-on buses in industrial controllers or set-top boxes, but not the lowest-power option for battery gear.
Lifecycle and sourcing — still an active line
Package and handling — 20-SOIC wide-body
The wide SOIC footprint is common for I2C controllers and interface ICs, and it is straightforward to hand-assemble or reflow. Standard MSL precautions apply — store the tubes in a dry environment if the seal is broken, and bake before reflow if the floor-life window has been exceeded.