Patents Assigned to Cambridge Analog Technologies, Inc.
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Publication number: 20120293232Abstract: A switched capacitor circuit includes a threshold detector to generate a threshold detection signal when a difference between first and second input signals crosses a predetermined level. A coarse current source produces a coarse ramp. A series sampling capacitor samples a coarse output voltage when the threshold detector indicates a first threshold crossing. The sampling capacitor is connected in series with a fine current source producing a fine ramp.Type: ApplicationFiled: May 20, 2011Publication date: November 22, 2012Applicant: Cambridge Analog Technologies, Inc.Inventors: Matthew Guyton, Hae-Seung Lee
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Publication number: 20120218013Abstract: A phase-locked loop circuitry includes an oscillator circuitry having an input and an output. A phase detector circuit is connected to the output of the oscillator circuitry and has outputs thereof. A digital loop filter circuit is connected to the outputs of the phase detector circuitry and has outputs thereof. The outputs of the digital loop filter circuit are coupled, through a summing circuit, to the input of the oscillator circuitry. Values associated with the outputs of the digital loop filter circuit are updated concurrently based upon values associated with the outputs of the phase detector circuitry. One output of the digital loop filter circuitry has a high-pass transfer function.Type: ApplicationFiled: August 26, 2011Publication date: August 30, 2012Applicant: Cambridge Analog Technologies, Inc.Inventors: Denis Clarke Daly, Matthew Allen Zornig Straayer
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Publication number: 20110032003Abstract: A comparator based circuit with effective offset cancellation includes first and second amplifiers and an offset capacitor operatively connected to the first and second amplifiers. An offset voltage source generates an offset voltage. A first switch connects the offset voltage source to ground during a first time period. The first amplifier generates an output voltage in response to the first switch connecting the offset voltage source to ground during the first time period. A second switch connects the offset capacitor to ground during a second time period. The first switch disconnects the offset voltage source from ground during a third time period, and the second switch disconnects the offset capacitor from ground during the third time period.Type: ApplicationFiled: October 21, 2010Publication date: February 10, 2011Applicant: CAMBRIDGE ANALOG TECHNOLOGIES, INC.Inventor: Hae-Seung Lee
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Patent number: 7843233Abstract: A comparator based circuit with effective offset cancellation includes first and second amplifiers and an offset capacitor operatively connected to the first and second amplifiers. An offset voltage source generates an offset voltage. A first switch connects the offset voltage source to ground during a first time period. The first amplifier generates an output voltage in response to the first switch connecting the offset voltage source to ground during the first time period. A second switch connects the offset capacitor to ground during a second time period. The first switch disconnects the offset voltage source from ground during a third time period, and the second switch disconnects the offset capacitor from ground during the third time period.Type: GrantFiled: March 15, 2007Date of Patent: November 30, 2010Assignee: Cambridge Analog Technologies, Inc.Inventor: Hae-Seung Lee
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Patent number: 7737732Abstract: A sample-data analog circuit includes a level-crossing detector. The level-crossing detector controls sampling switches to provide a precise sample of the output voltage when the level-crossing detector senses the predetermined level crossing of the input signal. A multiple segment ramp waveform generator is used in the sample-data analog circuits. The ramp waveform generator includes an amplifier, a variable current source, and a voltage detection circuit coupled to the current source to control the change in the amplitude of the current. The ramp generator produces constant slope within each segment regardless of the load condition. The sample-data analog circuit also utilizes variable bandwidths and thresholds.Type: GrantFiled: July 18, 2006Date of Patent: June 15, 2010Assignee: Cambridge Analog Technologies, Inc.Inventor: Hae-Seung Lee
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Patent number: 7616145Abstract: A switched capacitor circuit includes a first level-crossing detector to generate a level-crossing detection signal when an input signal crosses a first predetermined level. A first waveform generator generates a first predetermined waveform and a second waveform generator generates a second predetermined waveform. A second level-crossing detector generates a second level-crossing detection signal when said second predetermined waveform crosses a voltage reference level a second time. A second switch is coupled to the second level-crossing detector, and a third switch is coupled to the first level-crossing detector. The second switch turns OFF when the second level-crossing detection signal indicates the second predetermined waveform crossed the voltage reference level a second time. The third switch turns OFF when the first level-crossing detection signal indicates the input signal crossed the first predetermined level.Type: GrantFiled: July 23, 2008Date of Patent: November 10, 2009Assignee: Cambridge Analog Technologies, Inc.Inventor: Hae Seung Lee
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Patent number: 7532042Abstract: A sampling circuit includes an input voltage source; a first switch having an input operatively connected to the input voltage source; a sampling capacitor operatively connected to an output of the first switch; an operational amplifier having an inverting input operatively connected to the sampling capacitor; a second switch operatively connected across the inverting input of the operational amplifier and an output of the operational amplifier; and a second capacitor operatively connected to the output of the first switch. The first switch has a variable parasitic capacitance, and the second capacitor has a substantially more linear capacitance than the variable parasitic capacitance and is in parallel with the variable parasitic capacitance. A combined variable parasitic capacitance and capacitance of said switch capacitor is more linear than the variable parasitic capacitance of the first switch.Type: GrantFiled: January 10, 2007Date of Patent: May 12, 2009Assignee: Cambridge Analog Technologies, Inc.Inventor: Hae-Seung Lee
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Patent number: 7522086Abstract: A switched capacitor circuit includes a first level-crossing detector to generate a level-crossing detection signal when an input signal crosses a first predetermined level. A first waveform generator generates a first predetermined waveform and a second waveform generator generates a second predetermined waveform. A second level-crossing detector generates a second level-crossing detection signal when said second predetermined waveform crosses a voltage reference level a second time. A second switch is coupled to the second level-crossing detector, and a third switch is coupled to the first level-crossing detector. The second switch turns OFF when the second level-crossing detection signal indicates the second predetermined waveform crossed the voltage reference level a second time. The third switch turns OFF when the first level-crossing detection signal indicates the input signal crossed the first predetermined level.Type: GrantFiled: December 28, 2006Date of Patent: April 21, 2009Assignee: Cambridge Analog Technologies, Inc.Inventor: Hae-Seung Lee
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Patent number: 7504866Abstract: A sampled-data analog circuit uses zero-crossing detector. A waveform generator produces a plurality of segments of ramp at the output. An output of a zero crossing detector controls a sampling switch, thereby causing a precise sample of the output voltage to be taken at the instant the zero crossing detector senses the zero crossing of the input signal. The waveform generator further includes a output hold function to maintain the output voltage.Type: GrantFiled: December 28, 2006Date of Patent: March 17, 2009Assignee: Cambridge Analog Technologies, Inc.Inventor: Hae-Seung Lee
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Patent number: 7486115Abstract: A sampled-data analog circuit includes a level-crossing detector. The level-crossing detector controls sampling switches to provide a precise sample of the output voltage when the level-crossing detector senses the predetermined level crossing of the input signal. The level-crossing detection may be a zero-crossing detection. An optional common-mode feedback circuit can keep the output common-mode voltage substantially constant.Type: GrantFiled: June 16, 2006Date of Patent: February 3, 2009Assignee: Cambridge Analog Technologies, Inc.Inventor: Hae-Seung Lee
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Patent number: 7459942Abstract: A sampled-data analog circuit includes a level-crossing detector. The level-crossing detector controls sampling switches to provide a precise sample of the output voltage when the level-crossing detector senses the predetermined level crossing of the input signal. The level-crossing detection may be a zero-crossing detection. An optional common-mode feedback circuit can keep the output common-mode voltage substantially constant.Type: GrantFiled: June 16, 2006Date of Patent: December 2, 2008Assignee: Cambridge Analog Technologies, Inc.Inventor: Hae-Seung Lee