Switching logic driver with overcurrent protection

A logic driver for providing output power, received as input power from an external power source, said output power switched between two voltage levels in response to an input bistate data bit, comprising:

• input means for receiving an input bistate data bit and generating a control command corresponding to the state of an input bistate data bit said input means comprising,
• (a) input control means for receiving an input bistate data bit and and an overcurrent command in the form of a pair of bistate overcurrent signals, for performing predetermined boolean logic on an input bistate data bit and a pair of input bistate overcurrent signals, and providing a corresponding pair of output bistate logic signals, and
• (b) interface means for receiving said pair of output bistate logic signals and converting the state of each output logic signal to a corresponding analog signal with each converted logic signals forming said control commands;
• switch means for receiving input power, said switch means responsive to said control command for, providing output power to an output at a first predetermined voltage level when an input bistate data bit is of a first state and at a second predetermined voltage level when an input bistate data bit is of a second state;
• sense means coupled to said switch means for detecting a level of current in said input power and providing a corresponding current level indication;
• and
• overcurrent means, responsive to said current level indication, for generating an overcurrent command when said current level indication exceeds a predetermined level, said input means being further responsive to said overcurrent command for modifying said control command, said switch means responsive to said modified control command for disabling the providing of output power at the corresponding predetermined voltage level.

A logic driver for coupling input power as output power to a load in response to a bistate input signal, comprising:

• bistate switch means for receiving input power and responsive to a bistate input signal for, while in a switch first state in response to an input signal first state, changing to a switch second state in response to an input signal second state, and for, while in a switch second state, changing to said switch first state in response to said input signal first state, said switch means providing output power to a load when in said switch first state;
• bistate controller means coupled to said switch means for, while in a controller first state, changing to a controller second state when the level of current in output power from said switch means exceeds a predetermined level, said controller means for generating a control signal when in said controller second state and said switch means responsive to said control signal for changing to said switch second state, and said controller means for, while in said controller second state changing to said controller first state in response to said input signal second state wherein said controller means comprises, means for sensing the level of current in said output power and providing a corresponding sense signal, and thyristor means responsive to said sense signal for generating said control signal when said sense signal exceeds a predetermined value, said thyristor means including a thyristor having a gate, an anode and a cathode, said gate coupled to said sense means and one of said anode and cathode adapted for receiving input power and the other of said anode and cathode coupled to said switch means wherein said thyristor diverts input power from said switch means so as to change said switch means from said switch first state to said switch second state.