Patent ID: 7719324

Claim:
An apparatus including a low voltage differential signal transmitter with output power control, comprising: first and second power supply electrodes; first and second input signal electrodes to convey a differential input signal; first and second output signal electrodes to couple to a load impedance and convey a differential output signal corresponding to said differential input signal and including a signal voltage and a signal current; current source circuitry coupled to said first power supply electrode and responsive to a current control signal by providing a supply current; differential amplifier circuitry coupled to said current source circuitry, said second power supply electrode, said first and second input signal electrodes, and said first and second output signal electrodes, and responsive to said supply current and said differential input signal by providing said signal current and a sense voltage related to said signal current, wherein said signal current and said sense voltage have respective first magnitudes when said load impedance is coupled to said first and second output signal electrodes, and said signal current and said sense voltage have respective second magnitudes when said load impedance is not coupled to said first and second output signal electrodes; and voltage sensing circuitry coupled to said differential amplifier circuitry and said current source circuitry, and responsive to said sense voltage by providing said current control signal, wherein said supply current has higher and lower magnitudes when said sense voltage has said first and second magnitudes, respectively.