System and method of regulating the distribution of power throughout a system through the use of uni-directional and bi-directional switches

摘要

An integrated solution to power management and distribution on a power bus, such as needed for an IEEE 1394 compliant expansion board. The integrated circuit includes a uni-directional switch on the input and one or more bi-directional switches on one or more outputs. Current can flow from the system power supply to any connected peripherals via the uni-directional switch and bi-directional switches, or can flow from the peripheral having the highest voltage power supply to the other peripherals via the bi-directional switches, but current will not flow back to the main system because of the unidirectional switch connected to the system power supply. Over-current conditions are quickly detected and the bi-directional switch is opened to prevent damage or over-heating. The switches are preferably fabricated as power FETs using NMOS technology. Several integrated circuits can be cascaded together to accommodate multiple peripherals.