Apparatus and method for termination powered differential interface periphery
First Claim
1. A power recovery circuit of a transmitter for recovering power from the terminating resistors of a termination power supply comprising:
- a bias control circuit having at least a pair of current sensing and control elements coupled to connected sources of a differential driver pair to provide a predetermined bias to the connected sources, the differential driver pair being coupled to the terminating resistors;
a startup circuit coupled to the terminating resistors, the start up circuit enabled to provide an initial starting bias voltage and current to the bias control circuit when the termination power supply is enabled; and
,a voltage regulator having an input coupled to an output of the bias control circuit to regulate an output voltage of the power recovery circuit;
the power recovery circuit using current supplied to the differential driver pair from the termination power supply and the voltage at the connected sources of the differential driver pair to provide regulated power from the voltage regulator to at least a portion of the peripheral circuits of the transmitter.
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Accused Products
Abstract
An apparatus and method for supplying power to the peripheral circuits of a transmitter circuit, especially an HDMI transmitter circuit, is disclosed. In an HDMI transmitter the termination resistors of the output driver are part of the receiver. DC power for the driver is supplied through these termination resistors. In prior art implementations of circuits this power, supplied by the receiver circuit, is wasted in the DC set-up circuit of the differential line driver. It is suggested to use this wasted power from the remote termination to power selected peripheral circuits of the transmitter. The use of this wasted power in the line driver for powering the peripheral circuits reduces the total system power.
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Citations
17 Claims
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1. A power recovery circuit of a transmitter for recovering power from the terminating resistors of a termination power supply comprising:
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a bias control circuit having at least a pair of current sensing and control elements coupled to connected sources of a differential driver pair to provide a predetermined bias to the connected sources, the differential driver pair being coupled to the terminating resistors; a startup circuit coupled to the terminating resistors, the start up circuit enabled to provide an initial starting bias voltage and current to the bias control circuit when the termination power supply is enabled; and
,a voltage regulator having an input coupled to an output of the bias control circuit to regulate an output voltage of the power recovery circuit; the power recovery circuit using current supplied to the differential driver pair from the termination power supply and the voltage at the connected sources of the differential driver pair to provide regulated power from the voltage regulator to at least a portion of the peripheral circuits of the transmitter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for powering at least some peripheral circuits of a differential output driver of a transmitter comprising:
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recovering the wasted power from driver circuits of the transmitter; regulating the recovered power; and
,supplying the regulated power as voltage and current outputs to power at least a portion of the peripheral circuits of the transmitter. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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Specification