Patents by Inventor Cameron Lacy
Cameron Lacy has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 10114400Abstract: A BGR circuit for sub-1V ICs utilizes a voltage chopping circuit and/or a current chopping circuit and a low-frequency filter to stabilize the output reference voltage that is generated by an op-amp, a current mirror circuit, a CTAT stage, a PTAT stage, and an output stage. The voltage chopping circuit reduces input offset and 1/f noise by periodically alternating (time-averaging) the negative temperature dependent and positive temperature dependent voltages supplied by the CTAT and PTAT stages to the op-amp's input terminals. The current chopping circuit minimizes current variations caused by process-related differences in the current mirror devices by periodically alternating (time-averaging) three balanced currents generated by the current mirror circuit such that each current is transmitted equally to each of the CTAT, PTAT and output stages. The filter serves to maintain loop stability and remove the low frequency noise generated by the applied voltage and/or current chopping operations.Type: GrantFiled: September 30, 2016Date of Patent: October 30, 2018Assignee: Synopsys, Inc.Inventors: Cameron Lacy, Michael W. Lynch, Sergei Uhanov
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Publication number: 20180095491Abstract: A BGR circuit for sub-1V ICs utilizes a voltage chopping circuit and/or a current chopping circuit and a low-frequency filter to stabilize the output reference voltage that is generated by an op-amp, a current mirror circuit, a CTAT stage, a PTAT stage, and an output stage. The voltage chopping circuit reduces input offset and 1/f noise by periodically alternating (time-averaging) the negative temperature dependent and positive temperature dependent voltages supplied by the CTAT and PTAT stages to the op-amp's input terminals. The current chopping circuit minimizes current variations caused by process-related differences in the current mirror devices by periodically alternating (time-averaging) three balanced currents generated by the current mirror circuit such that each current is transmitted equally to each of the CTAT, PTAT and output stages. The filter serves to maintain loop stability and remove the low frequency noise generated by the applied voltage and/or current chopping operations.Type: ApplicationFiled: September 30, 2016Publication date: April 5, 2018Inventors: Cameron Lacy, Michael W. Lynch, Sergei Uhanov
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Patent number: 8067957Abstract: A high-speed universal serial bus (USB) transceiver includes a voltage-mode architecture for generating a USB signal. The voltage mode architecture reduces power consumption by reducing the current requirements for high-speed USB communications. The USB transceiver can include a reference voltage generator, a resistive element, and a switching element for completing and breaking a circuit including the reference voltage generator, the resistive element, and a data pin of a USB port to generate half of the differential USB signal (e.g., the D+ signal). A similar circuit can be used to generate the other half of the differential USB signal (i.e., the D? signal). The resistive element can be a set of parallel resistors in the transceiver, with the set of parallel resistors being specifically selected from a larger population of resistors to provide the specified resistance (45?±10%) in the USB transceiver.Type: GrantFiled: October 5, 2010Date of Patent: November 29, 2011Assignee: Synopsys, Inc.Inventors: Scott Howe, Dino A. Toffolon, Cameron Lacy, Euhan Chong
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Publication number: 20110019763Abstract: A high-speed universal serial bus (USB) transceiver includes a voltage-mode architecture for generating a USB signal. The voltage mode architecture reduces power consumption by reducing the current requirements for high-speed USB communications. The USB transceiver can include a reference voltage generator, a resistive element, and a switching element for completing and breaking a circuit including the reference voltage generator, the resistive element, and a data pin of a USB port to generate half of the differential USB signal (e.g., the D+ signal). A similar circuit can be used to generate the other half of the differential USB signal (i.e., the D? signal). The resistive element can be a set of parallel resistors in the transceiver, with the set of parallel resistors being specifically selected from a larger population of resistors to provide the specified resistance (45 ?±10%) in the USB transceiver.Type: ApplicationFiled: October 5, 2010Publication date: January 27, 2011Applicant: Synopsys, Inc.Inventors: Scott Howe, Dino A. Toffolon, Cameron Lacy, Euhan Chong
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Patent number: 7816942Abstract: A high-speed universal serial bus (USB) transceiver includes a voltage-mode architecture for generating a USB signal. The voltage mode architecture reduces power consumption by reducing the current requirements for high-speed USB communications. The USB transceiver can include a reference voltage generator, a resistive element, and a switching element for completing and breaking a circuit including the reference voltage generator, the resistive element, and a data pin of a USB port to generate half of the differential USB signal (e.g., the D+ signal). A similar circuit can be used to generate the other half of the differential USB signal (i.e., the D? signal). The resistive element can be a set of parallel resistors in the transceiver, with the set of parallel resistors being specifically selected from a larger population of resistors to provide the specified resistance (45?±10%) in the USB transceiver.Type: GrantFiled: January 13, 2010Date of Patent: October 19, 2010Assignee: Synopsys, Inc.Inventors: Scott Howe, Dino A. Toffolon, Cameron Lacy, Euhan Chong
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Publication number: 20100109706Abstract: A high-speed universal serial bus (USB) transceiver includes a voltage-mode architecture for generating a USB signal. The voltage mode architecture reduces power consumption by reducing the current requirements for high-speed USB communications. The USB transceiver can include a reference voltage generator, a resistive element, and a switching element for completing and breaking a circuit including the reference voltage generator, the resistive element, and a data pin of a USB port to generate half of the differential USB signal (e.g., the D+ signal). A similar circuit can be used to generate the other half of the differential USB signal (i.e., the D? signal). The resistive element can be a set of parallel resistors in the transceiver, with the set of parallel resistors being specifically selected from a larger population of resistors to provide the specified resistance (45?±10%) in the USB transceiver.Type: ApplicationFiled: January 13, 2010Publication date: May 6, 2010Applicant: Synopsys, Inc.Inventors: Scott Howe, Dino A. Toffolon, Cameron Lacy, Euhan Chong
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Patent number: 7671630Abstract: A high-speed universal serial bus (USB) transceiver includes a voltage-mode architecture for generating a USB signal. The voltage mode architecture reduces power consumption by reducing the current requirements for high-speed USB communications. The USB transceiver can include a reference voltage generator, a resistive element, and a switching element for completing and breaking a circuit including the reference voltage generator, the resistive element, and a data pin of a USB port to generate half of the differential USB signal (e.g., the D+ signal). A similar circuit can be used to generate the other half of the differential USB signal (i.e., the D? signal). The resistive element can be a set of parallel resistors in the transceiver, with the set of parallel resistors being specifically selected from a larger population of resistors to provide the specified resistance (45 ?±10%) in the USB transceiver.Type: GrantFiled: July 29, 2005Date of Patent: March 2, 2010Assignee: Synopsys, Inc.Inventors: Scott Howe, Dino A. Toffolon, Cameron Lacy, Euhan Chong
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Patent number: 7522659Abstract: A Universal Serial Bus (USB) 2.0 transceiver includes a legacy full speed and low speed (FS/LS) USB driver that includes multiple output stages. The multiple output stages are connected in parallel to an output terminal. By sequentially providing the USB data to the multiple output stages, the USB signal at the output terminal will transition between logic states in an incremental fashion as the multiple output stages sequentially switch their individual output states. Consequently, the rise/fall time for the legacy FS/LS USB driver is controlled not by the strength of the inverter transistors in the output stages, but rather by the number of stages and the time interval between application of the USB data to each stage. Therefore, by selecting an appropriate number of output stages and an appropriate timing interval, accurate control over full speed and low speed USB signal rise/fall times can be provided.Type: GrantFiled: September 19, 2005Date of Patent: April 21, 2009Assignee: Synopsys, Inc.Inventors: Cameron Lacy, Dino A. Toffolon, Scott Howe
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Publication number: 20070064778Abstract: A USB 2.0 transceiver includes a legacy full speed and low speed (FS/LS) USB driver that includes multiple output stages. The multiple output stages are connected in parallel to an output terminal. By sequentially providing the USB data to the multiple output stages, the USB signal at the output terminal will transition between logic states in an incremental fashion as the multiple output stages sequentially switch their individual output states. Consequently, the rise/fall time for the legacy FS/LS USB driver is controlled not by the strength of the inverter transistors in the output stages, but rather by the number of stages and the time interval between application of the USB data to each stage. Therefore, by selecting an appropriate number of output stages and an appropriate timing interval, accurate control over full speed and low speed USB signal rise/fall times can be provided.Type: ApplicationFiled: September 19, 2005Publication date: March 22, 2007Applicant: Synopsys, Inc.Inventors: Cameron Lacy, Dino Toffolon, Scott Howe
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Publication number: 20070024327Abstract: A high-speed universal serial bus (USB) transceiver includes a voltage-mode architecture for generating a USB signal. The voltage mode architecture reduces power consumption by reducing the current requirements for high-speed USB communications. The USB transceiver can include a reference voltage generator, a resistive element, and a switching element for completing and breaking a circuit including the reference voltage generator, the resistive element, and a data pin of a USB port to generate half of the differential USB signal (e.g., the D+ signal). A similar circuit can be used to generate the other half of the differential USB signal (i.e., the D? signal). The resistive element can be a set of parallel resistors in the transceiver, with the set of parallel resistors being specifically selected from a larger population of resistors to provide the specified resistance (45 ?±10%) in the USB transceiver.Type: ApplicationFiled: July 29, 2005Publication date: February 1, 2007Applicant: Synopsys Inc.Inventors: Scott Howe, Dino Toffolon, Cameron Lacy, Euhan Chong