Bi-directional impedance matching circuit

An input and output integrated circuit, the input and output integrated circuit couplable through an interface to a channel, the input and output integrated circuit comprising:

• a first switchable impedance having an output impedance substantially equal to a channel impedance;
• a second switchable impedance having an input impedance substantially equal to the channel impedance;
• and
• an impedance controller coupled to the first switchable impedance and the second switchable impedance, the impedance controller having a plurality of operating modes in response to a plurality of control signals, wherein in a transmit mode of the plurality of operating modes, the impedance controller is capable of selectively coupling the first switchable impedance to the interface and providing an output signal to the interface, and wherein in a receive mode of the plurality of operating modes, the impedance controller is further capable of selectively coupling the second switchable impedance to the interface for reception of an input signal from the interface.

A bi-directional impedance matching integrated circuit, the bi-directional impedance matching integrated circuit couplable through an interface to a channel for signal transmission and reception, the channel having a channel impedance, the bi-directional impedance matching integrated circuit comprising:

• a first switchable impedance having an output impedance substantially equal to the channel impedance;
• a second switchable impedance having an input impedance substantially equal to the channel impedance;
• an impedance controller coupled to the first switchable impedance and the second switchable impedance, the impedance controller capable of coupling the first switchable impedance to the interface in response to a transmit control signal, the impedance controller further capable of coupling the second switchable impedance to the interface in response to a receive control signal, and the impedance controller further capable of uncoupling the first switchable impedance and the second switchable impedance from a power supply and from a ground potential in response to a low power control signal;
• and
• a mode selector coupled to the impedance controller, the mode selector capable of providing the transmit control signal, the receive control signal, and the low power control signal.