Back to results
US 8,786,321 B2Granted
Power harvesting in open drain transmitters
AssigneeSTMicroelectronics International N.V.
InventorsNitin Gupta, Tapas Nandy
Life of this patent
Estimating the term…
Abstract
A transmitter having at least one channel comprising a first differential circuit driven by a differential data signal, the first differential circuit configured to output the differential data at a first and second output and a first control circuit coupled between the first differential circuit and the first and second output, the first control circuit driven by a drive voltage.
Claims26
A transmitter comprising:
- a channel including:
- a differential output line;
- a first differential circuit including:
- a differential input configured to receive a differential input signal, and a differential output coupled to the differential output line of the channel;
- and
- a first control circuit coupled between the differential output of the first differential circuit and the differential output line of the channel, the first control circuit having an input configured to receive a first control signal,
- wherein the first differential circuit includes a p-channel MOSFET,
- wherein the differential output line is configured to couple to a receiver,
- wherein the first differential circuit is configured to draw current from the receiver,
- wherein a voltage of the first control signal is less than or equal to a voltage of a power supply signal recovered from the current drawn from the receiver plus a threshold voltage of an n-channel MOSFET plus a threshold voltage of a p-channel MOSFET,
- wherein the first control signal is provided by a control signal generating circuit having one or more components supplied by a power supply voltage recovered from a drive signal provided at a terminal of the first differential circuit,
- wherein:
- the transmitter further comprises the control signal generating circuit;
- the control signal generating circuit includes:
- a second differential circuit driven by the differential input signal;
- and
- a voltage controller for controlling a voltage of the first control signal in response to a voltage control signal.
14 more elements
A circuit board comprising:
- a transmitter having a channel and a voltage regulator,
- wherein the channel includes:
- a first differential circuit including:
- a differential input configured to receive a differential input signal, and a differential output coupled to a differential output terminal of the channel;
- and
- a first control circuit coupled between the differential output of the first differential circuit and the differential output terminal of the channel, the first control circuit having an input configured to receive a control signal,
- wherein the voltage regulator is configured to regulate a voltage of a power supply signal recovered from a current drawn by the transmitter from a receiver coupled to the channel,
- wherein the voltage of the power supply signal recovered from the current drawn from the receiver is less than a voltage at a node coupled between the first control circuit and the differential output of the first differential circuit, and
- wherein a voltage of the control signal is less than or equal to the voltage of the power supply signal recovered from the current drawn from the receiver plus a threshold voltage of an n-channel MOSFET plus a threshold voltage of a p-channel MOSFET.
6 more elements
A system comprising:
- a high-definition multimedia interface (HDMI) receiver;
- and
- an HDMI transmitter configured to transmit data to the HDMI receiver, the HDMI transmitter having a channel and a voltage regulator,
- wherein the channel includes:
- a first differential circuit including:
- a differential input configured to receive a differential input signal, and a differential output coupled to a differential output terminal of the channel, and
- a first control circuit coupled between the differential output of the first differential circuit and the differential output terminal of the channel, the first control circuit having an input configured to receive a control signal,
- wherein the voltage regulator is configured to regulate a voltage of a power supply signal recovered from a current drawn by the HDMI transmitter from the HDMI receiver,
- wherein the voltage of the power supply signal recovered from the current drawn from the HDMI receiver is less than a voltage at a node coupled between the first control circuit and the differential output of the first differential circuit, and
- wherein a voltage of the control signal is less than or equal to the voltage of the power supply signal recovered from the current drawn from the HDMI receiver plus a threshold voltage of an n-channel MOSFET plus a threshold voltage of a p-channel MOSFET.
7 more elements
Dependencies are inferred from the claim text.