Abstract: The invention provides novel classes of HCV therapeutics that are orally available, safe and effective HCV NS3/4A protease inhibitors and are less susceptible to drug resistance than existing therapeutics. The invention also relates to pharmaceutical composition of these compounds and methods of preparation and use thereof.

Abstract: The present application provides compounds and methods of treating viral infections, including viral infections caused by HIV or HTLV.

Abstract: The invention provides novel classes of HCV therapeutics that are orally available, safe and effective HCV NS3/4A protease inhibitors and are less susceptible to drug resistance than existing therapeutics. The invention also relates to pharmaceutical composition of these compounds and methods of preparation and use thereof.

Abstract: The present application provides compounds and methods of treating viral infections, including viral infections caused by HIV or HTLV.

Abstract: The invention provides novel classes of HCV therapeutics that are orally available, safe and effective HCV NS3/4A protease inhibitors and are less susceptible to drug resistance than existing therapeutics. The invention also relates to pharmaceutical composition of these compounds and methods of preparation and use thereof.

Abstract: The invention provides novel classes of HCV therapeutics that are orally available, safe and effective HCV NS3/4A protease inhibitors and are less susceptible to drug resistance than existing therapeutics. The invention also relates to pharmaceutical composition of these compounds and methods of preparation and use thereof.

Abstract: The present application provides compounds and methods of treating viral infections, including viral infections caused by HIV or HTLV.

Abstract: The invention provides novel classes of HCV therapeutics that are orally available, safe and effective HCV NS3/4A protease inhibitors and are less susceptible to drug resistance than existing therapeutics. The invention also relates to pharmaceutical composition of these compounds and methods of preparation and use thereof.

Abstract: A highly agile low phase noise frequency synthesizer is provided for rapid generation of frequency specific signals. The frequency synthesizer is capable of rapidly generating signals at different output frequencies while maintaining low cross-coupling. Two or more signal generators utilize a reference frequency to generate two or more signals. These signals are limit processed to reduce cross-coupling prior to being presented to a switch. Responsive to a control signal, the switch outputs one of the signals to a frequency modification device, such as a frequency divider or multiplier. Responsive to a control signal, the frequency modification device scales the frequency of the switch output to convert the frequency of the switch output signal to a desired output frequency. By maintaining sufficient frequency separation between the switch input signals cross-coupling and phase noise is minimized and implementation on an integrated circuit may be achieved.

Abstract: Described are novel protease inhibitors and methods for using said protease inhibitors in the treatment of human immunodeficiency virus (HIV) infection.

Abstract: A highly agile low phase noise frequency synthesizer is provided for rapid generation of frequency specific signals. The frequency synthesizer is capable of rapidly generating signals at different output frequencies while maintaining low cross-coupling. Two or more signal generators utilize a reference frequency to generate two or more signals. These signals are limit processed to reduce cross-coupling prior to being presented to a switch. Responsive to a control signal, the switch outputs one of the signals to a frequency modification device, such as a frequency divider or multiplier. Responsive to a control signal, the frequency modification device scales the frequency of the switch output to convert the frequency of the switch output signal to a desired output frequency. By maintaining sufficient frequency separation between the switch input signals cross-coupling and phase noise is minimized and implementation on an integrated circuit may be achieved.

Abstract: The present invention provides compounds and compositions for inhibiting Vif and methods for treating viral infection, e.g., HIV infection.

Abstract: A highly agile low phase noise frequency synthesizer is provided for rapid generation of frequency specific signals. The frequency synthesizer is capable of rapidly generating signals at different output frequencies while maintaining low cross-coupling. Two or more signal generators utilize a reference frequency to generate two or more signals. These signals are limit processed to reduce cross-coupling prior to being presented to a switch. Responsive to a control signal, the switch outputs one of the signals to a frequency modification device, such as a frequency divider or multiplier. Responsive to a control signal, the frequency modification device scales the frequency of the switch output to convert the frequency of the switch output signal to a desired output frequency. By maintaining sufficient frequency separation between the switch input signals cross-coupling and phase noise is minimized and implementation on an integrated circuit may be achieved.

Abstract: According to one exemplary embodiment, a frequency synthesizer module includes a loop filter, where the loop filter includes a capacitor having a first terminal and a second terminal. The frequency synthesizer module further includes a loop filter calibration module coupled to the capacitor in the loop filter. The loop filter calibration module causes an initial capacitance between the first terminal and the second terminal of the capacitor to increase to a target capacitance when the loop filter is in a calibration mode. The target capacitance can causes in increase in control of a bandwidth of the loop filter and a reduction in percent error of a unity gain bandwidth of the loop filter. The loop filter further includes a switched capacitor array configured to cause the initial capacitance to increase to the target capacitance in response to a digital feedback signal provided by the loop filter calibration module.

Abstract: According to one exemplary embodiment, a frequency synthesizer module includes a loop filter, where the loop filter includes a capacitor having a first terminal and a second terminal. The frequency synthesizer module further includes a loop filter calibration module coupled to the capacitor in the loop filter. The loop filter calibration module causes an initial capacitance between the first terminal and the second terminal of the capacitor to increase to a target capacitance when the loop filter is in a calibration mode. The target capacitance can causes in increase in control of a bandwidth of the loop filter and a reduction in percent error of a unity gain bandwidth of the loop filter. The loop filter further includes a switched capacitor array configured to cause the initial capacitance to increase to the target capacitance in response to a digital feedback signal provided by the loop filter calibration module.

Abstract: A system for direct modulation is disclosed. Embodiments of the direct modulator for shift-keying modulation include impressing baseband data on a radio frequency (RF) signal at an oscillator by controlling a digital divider using a sigma-delta modulator.

Abstract: A system for direct modulation is disclosed. Embodiments of the direct modulator for shift-keying modulation include impressing baseband data on a radio frequency (RF) signal at an oscillator by controlling a digital divider using a sigma-delta modulator.

Abstract: A synchronous prescaler is provided that has an input line for receiving an input signal, which is synchronized to a low order dual modulus prescaler. The dual modulus prescaler generally divides responsive to a mode command line, but may have a dead-zone period where it may fail to respond to a generated mode command. The dual modulus prescaler also has an output line that is synchronized to an extender section. The extender section is used to further divide the input signal, and is synchronized to an adjustable counter section. A sync controller circuit receives an output from the counter section, as well as a timing signal from the extender, and generates the mode signal on the mode command line. In this arrangement, the sync controller generates the mode signal at a time when the low order dual modulus is in a condition to change divide modes, thereby avoiding providing the signal during the dead-zone period.

Abstract: A highly agile low phase noise frequency synthesizer is provided for rapid generation of frequency specific signals. The frequency synthesizer is capable of rapidly generating signals at different output frequencies while maintaining low cross-coupling. Two or more signal generators utilize a reference frequency to generate two or more signals. These signals are limit processed to reduce cross-coupling prior to being presented to a switch. Responsive to a control signal, the switch outputs one of the signals to a frequency modification device, such as a frequency divider or multiplier. Responsive to a control signal, the frequency modification device scales the frequency of the switch output to convert the frequency of the switch output signal to a desired output frequency. By maintaining sufficient frequency separation between the switch input signals cross-coupling and phase noise is minimized and implementation on an integrated circuit may be achieved.

Abstract: A low power charge pump is provided that has complementary transistors capable of isolating switching noise from the input switching transistors. The charge pump uses charged currents that are matched in both magnitude and time to reduce switching noise in the output of the charge pump. The charge pump is also designed for use in a phase lock loop.