Patent ID: 6359465
Filing Date: 2002-03-19
Classification: H04L

Abstract:
A CMOS terminator circuit for connection to a network carrying small logic level signals from a network's first circuit to a network's second circuit in which a network's input terminal connects a terminator circuit to the network's second circuit to act as a terminator on the data line passing data from said first circuit to said second circuit, comprising:a terminator circuit (21) including a terminator reference circuit (30) generating logic â€˜1â€™ and logic â€˜0â€™ reference voltage levels and being coupled to a terminator input circuit (31) in said terminator circuit having a first and a second control device, and wherein said terminator circuit is switchable from a first state to a second state by a switching control signal (91) supplied to said reference circuit and to said input circuit (31), said terminator input circuit being coupled to said network input terminal (10) for connecting the network's first circuit to the network's second circuit, saod referemce circuit being tuned to a voltage level equal to the center of the incoming voltage swing between said logic â€˜1â€™ and â€˜0â€™ voltage levels of a reference circuit to provide to said input circuit a stable and well centered threshold voltage, said network input terminal being coupled to an adjustment section (33) for adjusting its terminator circuit input which is coupled to the network input terminal for connecting the network's first circuit to the network's second circuit; and wherein when the input terminal (10) is driven to rise above the center of said tuned reference voltage, the gate to source voltage in an input circuit (31) first control device (pfet 17) is driven to a lower voltage, and said input circuit first control device starts to turn-on and conduct current to a lower level power supply (12 or ground), whereas when a second control device has no conduction, no current will flow to a upper level power supply, but when the input terminal (10) falls below center of said tuned reference voltage said second control device turns on to conduct current to said upper level power supply, while said first control device is off.