Patent ID: 6531909
Filing Date: 2003-03-11
Classification: H03K

Abstract:
A switching circuit that switches an output circuit, said switching circuit comprising:a switch-ON circuit that provides a switch-ON current to said output circuit when an input signal is ON; a switch-OFF circuit that operates when said input signal is OFF; and a controlled current source coupled to said switch-ON circuit, said switch-OFF circuit, and said output circuit, wherein said controlled current source continually samples an output current from said output circuit and provides drive current to said output circuit in proportion to said output current, and provides at least a portion of said drive current to said switch-OFF circuit if said input signal is OFF, said output circuit comprising an output transistor and said controlled current source comprising a source transistor, and wherein said source transistor is coupled to said output transistor such that the respective voltages of an emitter and a base of said source transistor substantially match the voltages of an emitter and a base of said output transistor, respectively.