Patent ID: 7990672
Filing Date: 2011-08-02
Classification: G05F

Abstract:
1. A power supply system with low voltage protection comprising: an unregulated power supply; a power supply regulator connected to said unregulated power supply and generating a regulated power supply voltage; core logic connected to said power supply regulator and powered by said regulated power supply having at least one input and/or output; a first protection circuit connected to said unregulated power supply and generating a first low voltage protection signal indicating if said unregulated power supply voltage is below a first reference voltage; a second protection circuit connected to said regulated power supply and generating a second low voltage protection signal indicating if said regulated power supply voltage is below a second reference voltage, said second reference voltage less than said first reference voltage; a ports on control logic connected to said first and second low voltage protection circuits and generating a ports on control signal at least one input or output port, each port having an external connection, each port connected to a corresponding one of said at least one input and/or output of said core logic and to said ports on control logic, each port operable to a reference voltage generator connected to said unregulated power supply generating said second reference voltage and a third reference voltage, said second reference voltage greater than said third reference voltage; a third protection circuit connected to said regulated power supply and generating a second low voltage protection signal indicating if said regulated power supply voltage is below said second reference voltage, said third protection circuit including