Patents Assigned to Cosmic Circuits Private Limited
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Patent number: 8598860Abstract: A transient recovery circuit for switching devices. The transient recovery circuit includes a detecting circuit for detecting a rapid transient in an output voltage of a switching device by detecting a rate of the output voltage transient; an auxiliary controlling circuit in a feedback loop of the switching device for correcting the output voltage by changing a bandwidth of the feedback loop if the rapid transient is detected; and an initializing circuit for initializing the feedback loop to expected operating points in a continuous conduction mode after correcting the output voltage.Type: GrantFiled: September 30, 2011Date of Patent: December 3, 2013Assignee: Cosmic Circuits Private LimitedInventors: Hrishikesh Bhagwat, Rupak Ghayal, Saumitra Singh, Pawan Gupta, Prakash Easwaran
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Publication number: 20130127522Abstract: An electrical system for generating arbitrary voltage waveform includes a power supply unit for providing a supply voltage to the electrical system. One or more charge pumps are in electrical communication with the power supply unit. Each charge pump generates a voltage. The electrical system also includes a plurality of switches, a first switch among the plurality of switches coupled between a ground and an output terminal, other switches among the plurality of switches coupled between the one or more charge pumps and the output terminal. A control circuit is in electrical communication with the power supply unit, the plurality of switches and the one or more charge pumps, and is operable to control the voltage generated by the each charge pump and the plurality of switches. Voltages from the one or more charge pumps additively result in a variable output voltage that generates an arbitrary voltage waveform.Type: ApplicationFiled: November 22, 2011Publication date: May 23, 2013Applicant: Cosmic Circuits Private LimitedInventors: Anand Mohan, Sumeet Mathur
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Publication number: 20130021094Abstract: A circuit for optimizing a power management system. The circuit includes a first amplifier. The first amplifier is responsive to a first reference signal and operable to supply a first load current. The circuit also includes a second amplifier coupled to the first amplifier. The second amplifier is responsive to a second reference signal and operable to supply a second load current. The second load current is lower in magnitude than the first load current, thereby enabling the first amplifier to operate during a first load condition, and the second amplifier to operate during the first load condition and a second load condition. Further, the circuit includes a resistive element coupled to the first amplifier and the second amplifier, to isolate the first amplifier from the second amplifier.Type: ApplicationFiled: January 20, 2011Publication date: January 24, 2013Applicant: Cosmic Circuits Private LimitedInventors: Prasun Kali BHATTACHARYYA, Sumanth Chakkirala
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Publication number: 20130021092Abstract: An ultra low cut-off frequency filter. A filter circuit includes a control circuit responsive to an input signal and a feedback signal to generate a control signal. The filter circuit includes a controllable resistor coupled to the control circuit. The controllable resistor is responsive to a reference signal and the control signal to generate the feedback signal. The filter circuit includes a feedback path coupled to the control circuit and the controllable resistor to couple the feedback signal from the controllable resistor to the control circuit, thereby removing noise from at least one of the input signal and the reference signal, and preventing voltage error in the filter circuit.Type: ApplicationFiled: January 20, 2011Publication date: January 24, 2013Applicant: Cosmic Circuits Private LimitedInventors: Prasun Kali BHATTACHARYYA, Sumanth Chakkirala, Prakash Easwaran
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Publication number: 20120319789Abstract: A relaxation oscillator circuit with reduced sensitivity of oscillation frequency to comparator delay variation includes a first current source that generates charging current, a second current source coupled to the first current source to generate reference voltage, a resistor coupled to the second current source to enable generation of the reference voltage, a capacitor coupled to the first current source that is charged based on the charging current, a comparator responsive to voltage corresponding to the capacitor and the reference voltage to generate output voltage, a peak detector coupled to the capacitor to generate peak voltage, an error detector coupled to the peak detector and the second current source to generate an error based on the peak voltage and the reference voltage, and a controller coupled to the error detector to control one of the charging current, offset voltage input to the comparator, and capacitance of the capacitor.Type: ApplicationFiled: November 22, 2011Publication date: December 20, 2012Applicant: Cosmic Circuits Private LimitedInventors: Prasenjit Bhowmik, Rishi Mathur, Sriram Ganesan, Sunil Rajan
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Publication number: 20120299580Abstract: A transient recovery circuit for switching devices. The transient recovery circuit includes a detecting circuit for detecting a rapid transient in an output voltage of a switching device by detecting a rate of the output voltage transient; an auxiliary controlling circuit in a feedback loop of the switching device for correcting the output voltage by changing a bandwidth of the feedback loop if the rapid transient is detected; and an initializing circuit for initializing the feedback loop to expected operating points in a continuous conduction mode after correcting the output voltage.Type: ApplicationFiled: September 30, 2011Publication date: November 29, 2012Applicant: Cosmic Circuits Private LimitedInventors: Hrishikesh BHAGWAT, Rupak Ghayal, Saumitra Singh, Pawan Gupta, Prakash Easwaran
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Patent number: 8242762Abstract: A transient recovery circuit for switching devices. The transient recovery circuit includes a detecting circuit for detecting a rapid transient in an output voltage of a switching device by detecting a rate of the output voltage transient; an auxiliary controlling circuit in a feedback loop of the switching device for correcting the output voltage by changing a bandwidth of the feedback loop if the rapid transient is detected; and an initializing circuit for initializing the feedback loop to expected operating points in a continuous conduction mode after correcting the output voltage.Type: GrantFiled: May 6, 2009Date of Patent: August 14, 2012Assignee: Cosmic Circuits Private LimitedInventors: Hrishikesh Bhagwat, Rupak Ghayal, Saumitra Singh, Pawan Gupta, Prakash Easwaran
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Patent number: 8237422Abstract: Efficient switch cascode architecture for switching devices, such as switching regulators. The cascode architecture includes a switching stage responsive to an external driver signal for switching transitions, and a bias generator operative to bias the cascode transistor of the switching stage to protect the switching stage from damage during the switching transitions.Type: GrantFiled: May 9, 2009Date of Patent: August 7, 2012Assignee: Cosmic Circuits Private LimitedInventors: Saumitra Singh, Rupak Ghayal, Chakravarthy Srinivasan, Prakash Easwaran
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Publication number: 20120176112Abstract: A circuit for sensing load current of a voltage regulator. The circuit includes a power transistor and a minor transistor. A first transistor sizing circuit is coupled to the power transistor and is operable to control size of the power transistor based on a bias voltage of the power transistor, thereby regulating a first voltage for varying load conditions. The circuit also includes a feedback amplifier coupled to the power transistor and the mirror transistor. A transistor is coupled to the feedback amplifier and the mirror transistor. An analog to digital converter (ADC) is coupled to the transistor. A second transistor sizing circuit is coupled to the mirror transistor, the transistor, and the ADC. The second transistor sizing circuit is responsive to an output voltage to control size of the minor transistor, thereby ensuring that accuracy of output voltage sensed by ADC is not limited by ADC's resolution.Type: ApplicationFiled: April 8, 2011Publication date: July 12, 2012Applicant: Cosmic Circuits Private LimitedInventors: Saumitra SINGH, Rupak Ghayal, Ravindra Kumar N
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Capacitor based digital to analog converter layout design for high speed analog to digital converter
Patent number: 8149152Abstract: A method and system for capacitor based digital to analog converter design layout for high speed analog to digital converter are provided. The method includes arranging a plurality of metal plates to form the capacitor. Each of the plurality of metal plates includes a driven plate and a common plate. The method also includes generating a plurality of interconnects in the common plate and extending the driven plate over the plurality of interconnects. Further, the method includes shielding the common plate by the driven plate. The system includes an analog to digital converter. The analog to digital converter also includes capacitor based digital to analog converter and digital logic for controlling digital operations in the analog to digital converter. The capacitor based digital to analog converter includes a plurality of capacitors, and a comparator for comparing the analog output from the digital to analog converter with a ground potential.Type: GrantFiled: March 23, 2010Date of Patent: April 3, 2012Assignee: Cosmic Circuits Private LimitedInventors: Venkatesh Teeka Srinivasa Shetty, Govind Kulkarni, Srinivasan Chakravarthy, Sumeet Mathur -
Patent number: 8106706Abstract: A method for biasing a MOS transistor includes AC coupling an input signal from an amplifier stage to a gate of the MOS transistor. The method includes connecting a pair of diodes in an opposing parallel configuration to a bias transistor and a current source. Further, the method includes generating a DC bias voltage through the bias transistor and the current source. The method also includes clamping the voltage at drain of the bias transistor to a fixed voltage by a clamping circuit. Further, the method includes coupling the DC bias voltage to the gate of the MOS transistor through the pair of diodes.Type: GrantFiled: May 9, 2009Date of Patent: January 31, 2012Assignee: Cosmic Circuits Private LimitedInventors: Prakash Easwaran, Prasenjit Bhowmik, Sumeet Mathur
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Patent number: 8049472Abstract: Single inductor multiple output (SIMO) switching devices with efficient regulating circuits. The SIMO switching device includes a plurality of time division multiplexing (TDM) switches for switching current through an inductor of the SIMO switching device. The plurality of TDM switches produces a plurality of outputs. The SIMO switching device further includes an error calculation circuit operatively coupled to the plurality of outputs for determining a calculated error from the plurality of outputs; a time slot generation circuit for controlling the plurality of TDM switches according to the calculated error; and a pulse width modulation (PWM) control circuit operatively coupled to the time slot generation circuit for controlling a plurality of PWM switches of a switching stage of the SIMO switching device in a continuous conduction mode (CCM) of operation. The PWM switches are controlled according to the time slots generated by the time slot generation circuit.Type: GrantFiled: May 9, 2009Date of Patent: November 1, 2011Assignee: Cosmic Circuits Private LimitedInventors: Prakash Easwaran, Rupak Ghayal, Raghavendra Rao Haresamudram
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Patent number: 7868688Abstract: A current filter circuit is provided. The current filter circuit comprises a source transistor comprising a drain, a gate, and a source. The source of the source transistor is coupled to a reference voltage terminal, the gate of the source transistor is coupled to the gate of a mirror transistor, and the drain of the source transistor is coupled to a reference current source. The mirror transistor comprises a drain, a gate, and a source. The source of the mirror transistor is coupled to the reference voltage terminal, the gate is coupled to the gate of the source transistor, and the drain is coupled to a load. The current filter circuit comprises a low pass filter for filtering noise. The current filter circuit also comprises an impedance reduction circuit coupled to the drain of the mirror transistor for reducing bandwidth of the current filter circuit.Type: GrantFiled: May 9, 2009Date of Patent: January 11, 2011Assignee: Cosmic Circuits Private LimitedInventors: Prakash Easwaran, Prasenjit Bhowmik, Sumeet Mathur
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Patent number: 7821436Abstract: A system and method for reducing the power dissipated in an Analog to Digital Converter (ADC). The method includes the steps of: receiving a residue output from a previous phase of a plurality of clock phases where the plurality of clock phases includes a sample-and-hold phase and an amplifying phase for sampling and amplifying an analog input signal respectively, eliminating an effect of load on a residue amplifier when amplifying the residue output to generate an amplified residue output in the amplifying phase, and eliminating an effect of small feedback factor when sampling the amplified residue output in the sample-and-hold phase. Power advantage is achieved by sharing the load on the residue amplifier across the sample-and-hold phase and the amplifying phase rather than being fully present in any one of the clock phases. The present invention also provides a method for reducing the number of comparators used in ADCs.Type: GrantFiled: June 9, 2007Date of Patent: October 26, 2010Assignee: Cosmic Circuits Private LimitedInventors: Venkatesh Teeka Srinvasa Setty, Chandrashekar Lakshminarayanan, Prasun Kali Bhattacharya, Prasenjit Bhowmik, Chakravarthy Srinivasan, Mukesh Khatri, Sanjeeb Kumar Ghosh, Sumanth Chakkirala, Sundararajan Krishnan, Prakash Easwaran
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CAPACITOR BASED DIGITAL TO ANALOG CONVERTER LAYOUT DESIGN FOR HIGH SPEED ANALOG TO DIGITAL CONVERTER
Publication number: 20100253563Abstract: A method and system for capacitor based digital to analog converter design layout for high speed analog to digital converter are provided. The method includes arranging a plurality of metal plates to form the capacitor. Each of the plurality of metal plates includes a driven plate and a common plate. The method also includes generating a plurality of interconnects in the common plate and extending the driven plate over the plurality of interconnects. Further, the method includes shielding the common plate by the driven plate. The system includes an analog to digital converter. The analog to digital converter also includes capacitor based digital to analog converter and digital logic for controlling digital operations in the analog to digital converter. The capacitor based digital to analog converter includes a plurality of capacitors, and a comparator for comparing the analog output from the digital to analog converter with a ground potential.Type: ApplicationFiled: March 23, 2010Publication date: October 7, 2010Applicant: Cosmic Circuits Private LimitedInventors: Venkatesh Teeka Srinivasa SHETTY, Govind Kulkarni, Srinivasan Chakravarthy, Sumeet Mathur -
Patent number: 7675333Abstract: A Delay Locked Loop (DLL) and method for generating multiple equally spaced phases over a wide frequency range is disclosed. The DLL includes a delay line, and a control module. The delay line receives a reference clock signal and outputs a final delay clock signal in response to the reference clock signal. The delay line includes a plurality of delay cells connected in series. The plurality of delay cells generate a plurality of delay clock signals having equally spaced phases. The control module generates a phase control signal based on counting a number of pulses of the reference clock signal that are input to the delay line before occurrence of a first corresponding pulse of the final delay clock signal.Type: GrantFiled: June 10, 2007Date of Patent: March 9, 2010Assignee: Cosmic Circuits Private LimitedInventors: Prasenjit Bhowmik, Sundararajan Krishnan, Sriram Ganesan
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Patent number: 7570191Abstract: Methods and systems for designing a high resolution analog to digital converter (ADC) by eliminating the errors in the ADC stages. An error correction architecture and method eliminate the gain error and settling error of the residue amplifier in a pipelined ADC stage. A reference voltage error correction architecture and method eliminate the reference voltage error due to the sampling action in the ADC. The gain error correction method calculates the gain error using an error amplifier and eliminates the gain error at a later stage of the ADC. The reference voltage error correction method calculates the reference voltage error using an ideal reference voltage and corrects the error at a later stage of the ADC. Therefore, the constraints of gain and settling of the residue amplifier is significantly reduced.Type: GrantFiled: June 10, 2007Date of Patent: August 4, 2009Assignee: Cosmic Circuits Private LimitedInventors: Prakash Easwaran, Prasun Kali Bhattacharya, Venkatesh Teeka Srinivasa Shetty
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Patent number: 7570181Abstract: Methods and systems for input voltage droop compensation in video/graphics front-end systems. The method of an embodiment of the invention captures input voltage information supplied to an Analog-to-Digital Converter (ADC) operatively coupled to a bypass capacitor in a video/graphics front-end system; calculates a droop in the input voltage in ADC due to a charge sharing between an input sampling capacitor of the ADC and the bypass capacitor; and compensates for the value of the bypass capacitor using an output of the ADC. Embodiments of the invention provide an improved freedom in the choice of off-chip bypass capacitance in video/graphics front-end systems.Type: GrantFiled: June 10, 2007Date of Patent: August 4, 2009Assignee: Cosmic Circuits Private LimitedInventors: Sundararajan Krishnan, C. Srinivasan
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Patent number: 7548104Abstract: A delay line including a sequence of identical delay cells with improved gain and in built duty cycle distortion control and a method thereof is disclosed. Each delay cell of the sequence includes a current source, four transistors, and a load capacitor. A gate of the current source receives a voltage bias that controls a delay of the delay cell. A drain of the first transistor is connected to the drain of the current source. The first and second transistor gates receive an input clock signal. The second transistor drain is connected to the source of the current source. The third transistor gate and the load capacitor are also connected to the drain of the current source. The fourth transistor drain is connected to the third transistor drain. The fourth transistor gate is coupled to an output of a second consecutive delay cell for duty cycle distortion control.Type: GrantFiled: June 10, 2007Date of Patent: June 16, 2009Assignee: Cosmic Circuits Private LimitedInventors: Prasenjit Bhowmik, Sundararajan Krishnan, G. Sriram
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Patent number: 7538701Abstract: A system and method for improving the dynamic performance in an analog-to-digital converter (ADC) by randomizing the differential mismatch. The differential mismatch in an input analog signal is randomized by flipping the input signal and output signal randomly.Type: GrantFiled: June 9, 2007Date of Patent: May 26, 2009Assignee: Cosmic Circuits Private LimitedInventors: Venkatesh Teeka Srinivasa Shetty, Chandrashekar Lakshminarayanan, Prasun Kali Bhattacharya, Prasenjit Bhowmik, Srinivasan Chakravarthy, Mukesh Khatri, Sanjeeb Kumar Ghosh, Sumanth Chakkirala, Sundararajan Krishnan, Prakash Easwaran