Patents by Inventor Ambreesh Bhattad

Ambreesh Bhattad 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).

  • Publication number: 20180217623
    Abstract: A voltage regulator which provides an output current at an output voltage at an output node of the voltage regulator, based on an input voltage at an input node of the voltage regulator is described. The voltage regulator has an output amplification stage for deriving the output current at the output node from the input voltage at the input node in dependence of a drive voltage. Furthermore, the voltage regulator has a differential amplification stage to determine the drive voltage in dependence of the output voltage and in dependence of a reference voltage. In addition, the voltage regulator has an adaption unit to determine a capacitance indication of a capacitor value of an output capacitor coupled to the output node of the voltage regulator. The adaption unit also adapts the differential amplification stage in dependence of the capacitance indication.
    Type: Application
    Filed: November 20, 2017
    Publication date: August 2, 2018
    Inventors: Ambreesh Bhattad, Frank Kronmueller, Hande Kurnaz
  • Patent number: 9958892
    Abstract: A regulator configured to provide at an output node a load current at an output voltage is described. The regulator comprises a pass transistor for providing the load current at the output node. Furthermore, the regulator comprises feedback means for deriving a feedback voltage from the output voltage at the output node. In addition, the regulator comprises a differential amplifier configured to control the pass transistor in dependence of the feedback voltage and in dependence of a reference voltage. The regulator further comprises compensation means configured to determine a sensed current which is indicative of the load current at the output node. Furthermore, the compensation means are configured to adjust an operation point of the regulator in dependence of the sensed current and in dependence of a value of a track impedance of a conductive track which links the output node to a load.
    Type: Grant
    Filed: December 16, 2016
    Date of Patent: May 1, 2018
    Assignee: Dialog Semiconductor (UK) Limited
    Inventors: Hande Kurnaz, Ambreesh Bhattad, Gary Hague, Frank Kronmueller
  • Patent number: 9946276
    Abstract: A voltage regulator provides an output current at an output voltage, based on an input voltage. The voltage regulator has a pass transistor for deriving the output current. The voltage regulator contains a drive transistor forming a current mirror in conjunction with the pass transistor, such that the output current through the pass transistor is dependent on a drive current through the drive transistor. The voltage regulator comprises an auxiliary transistor arranged such that at least a fraction of the drive current through the drive transistor flows through the auxiliary transistor. The voltage regulator has amplification circuitry to set the drive current through the drive transistor depending on the output voltage and on a reference voltage. The voltage regulator further contains control circuitry to detect an indication for a dropout situation where a difference between the input voltage and the output voltage falls below a dropout voltage.
    Type: Grant
    Filed: February 10, 2017
    Date of Patent: April 17, 2018
    Assignee: Dialog Semiconductor (UK) Limited
    Inventors: Ambreesh Bhattad, Frank Kronmueller, Hande Kurnaz
  • Publication number: 20180081383
    Abstract: A regulator for providing a load current at a regulator output voltage to a load at an output of the regulator is described. The regulator has a differential input stage to provide a differential output voltage based on a reference voltage and based on the regulator output voltage. Furthermore, the regulator has an output driver to generate a control signal based on the differential output voltage. In addition, the regulator has a pass transistor to provide the load current in dependence of the control signal. The regulator also has clamping circuitry to sense an overvoltage indication which indicates that the pass transistor is being turned off. Furthermore, the clamping circuitry clamps the differential output voltage to a clamping voltage, if the overvoltage indication indicates that the pass transistor is being turned off.
    Type: Application
    Filed: November 29, 2017
    Publication date: March 22, 2018
    Inventors: Hande Kurnaz, Ambreesh Bhattad, Frank Kronmueller
  • Patent number: 9887535
    Abstract: A power providing circuit which is configured to provide a current at an output voltage to a load at an output of the power providing circuit is described. The power providing circuit comprises a power transistor which is configured to draw the current from a supply voltage, wherein a resistance of the power transistor is controlled using a control voltage which is applied to a control port of the power transistor. Furthermore, the power providing circuit comprises short circuit protection circuitry which is configured to couple the control port of the power transistor with a first port of the power transistor to put the power transistor in an off-state, subject to a drop of the output voltage.
    Type: Grant
    Filed: August 31, 2015
    Date of Patent: February 6, 2018
    Assignee: Dialog Semiconductor (UK) Limited
    Inventors: Ambreesh Bhattad, Frank Kronmueller, Christian Meindl, Anthony Clowes
  • Patent number: 9887674
    Abstract: A multi-stage amplifier, comprising a first amplifier stage is presented. The output of the first amplifier stage is coupled to a first terminal of a capacitor having a controllable capacitance. The input of a second amplifier stage is coupled to the output of the first amplifier stage and the first terminal of the capacitor. The output of the second amplifier stage is coupled to a second terminal of the capacitor and an output of the multi-stage amplifier. The input of a current sensing circuit is coupled with the output of the multi-stage amplifier. A control signal generator is coupled between the output of the current sensing circuit and a control terminal of the capacitor. The control signal generator provides a control signal to the capacitor in order to control or vary the capacitance of the capacitor.
    Type: Grant
    Filed: August 9, 2016
    Date of Patent: February 6, 2018
    Assignee: Dialog Semiconductor (UK) Limited
    Inventors: Carlos Zamarreno Ramos, Ambreesh Bhattad, Frank Kronmueller
  • Patent number: 9864386
    Abstract: A regulator for providing a load current at a regulator output voltage to a load at an output of the regulator is described. The regulator has a differential input stage to provide a differential output voltage based on a reference voltage and based on the regulator output voltage. Furthermore, the regulator has an output driver to generate a control signal based on the differential output voltage. In addition, the regulator has a pass transistor to provide the load current in dependence of the control signal. The regulator also has clamping circuitry to sense an overvoltage indication which indicates that the pass transistor is being turned off. Furthermore, the clamping circuitry clamps the differential output voltage to a clamping voltage, if the overvoltage indication indicates that the pass transistor is being turned off.
    Type: Grant
    Filed: April 5, 2016
    Date of Patent: January 9, 2018
    Assignee: Dialog Semiconductor (UK) Limited
    Inventors: Hande Kurnaz, Ambreesh Bhattad, Frank Kronmueller
  • Patent number: 9857816
    Abstract: An overshoot reduction circuit within a low dropout voltage regulator eliminates an overshoot at an output terminal resulting from a transient fault condition occurring at an input or output terminal. The overshoot reduction circuit monitors to sense if there is a transient fault condition occurring at the input or output terminal and provides a Miller capacitance at the output terminal of a differential amplifier of the low dropout voltage regulator to prevent the output of the differential amplifier from being discharged to ground during the transient. A control loop circuit balances current within an active load of the differential amplifier to clamp the output of the differential amplifier to its normal operating point. When the transient fault condition ends, the output voltage of the differential amplifier is set such that a pass transistor of the low dropout regulator responds quickly to resume the regulation to reduce or eliminate the overshoot.
    Type: Grant
    Filed: March 17, 2016
    Date of Patent: January 2, 2018
    Assignee: Dialog Semiconductor GmbH
    Inventor: Ambreesh Bhattad
  • Patent number: 9857817
    Abstract: A voltage regulator is described. It includes an amplification stage to control a voltage level of a first gain node and of a second gain node in response to an input voltage, to activate a first and a second output stage, respectively. It further includes the first output stage to source a current at an output node of the voltage regulator from a first potential. The voltage regulator includes the second output stage to sink a current at the output node to a second potential. The voltage regulator includes a first operating point control circuit to set the voltage level of the first gain node such that a first maintenance current is sourced by the first output stage; and/or a second operating point control circuit to set the voltage level of the second gain node such that a second maintenance current is sunk by the second output stage.
    Type: Grant
    Filed: January 17, 2017
    Date of Patent: January 2, 2018
    Assignee: Dialog Semiconductor (UK) Limited
    Inventors: Frank Kronmueller, Ambreesh Bhattad
  • Publication number: 20170322573
    Abstract: A voltage regulator provides an output current at an output voltage, based on an input voltage. The voltage regulator has a pass transistor for deriving the output current. The voltage regulator contains a drive transistor forming a current mirror in conjunction with the pass transistor, such that the output current through the pass transistor is dependent on a drive current through the drive transistor. The voltage regulator comprises an auxiliary transistor arranged such that at least a fraction of the drive current through the drive transistor flows through the auxiliary transistor. The voltage regulator has amplification circuitry to set the drive current through the drive transistor depending on the output voltage and on a reference voltage. The voltage regulator further contains control circuitry to detect an indication for a dropout situation where a difference between the input voltage and the output voltage falls below a dropout voltage.
    Type: Application
    Filed: February 10, 2017
    Publication date: November 9, 2017
    Inventors: Ambreesh Bhattad, Frank Kronmueller, Hande Kurnaz
  • Patent number: 9798340
    Abstract: A circuit is provided with inrush current protection through control of the output current at start-up by a current source that does not rely on the output capacitor and which provides a smooth transition from a controlled current mode during a start-up phase to a voltage regulation mode.
    Type: Grant
    Filed: October 23, 2014
    Date of Patent: October 24, 2017
    Assignee: Dialog Semiconductor GmbH
    Inventors: Ambreesh Bhattad, Frank Kronmueller
  • Patent number: 9740221
    Abstract: The present document relates to a pre-charge circuit of electronic circuits having Miller compensation and significant output capacitance such as LDOs or multistage amplifiers. The pre-charge circuit limits an inrush current right after enabling of the electronic circuit. The pre-charge circuit limits and clamps the fast charging of the Miller capacitor. A delay circuit disables the pre-charge circuit when the bias conditions of the Miller capacitor are close to normal bias conditions.
    Type: Grant
    Filed: March 28, 2013
    Date of Patent: August 22, 2017
    Assignee: Dialog Semiconductor GmbH
    Inventors: Pier Cavallini, Ambreesh Bhattad, Liu Liu
  • Publication number: 20170212542
    Abstract: A voltage regulator which provides an output current at an output voltage at an output node, based on an input voltage at an input node is described. The voltage regulator has an output amplification stage comprising a pass transistor for deriving the output current at the output node from the input voltage at the input node; and comprising a driver stage to set a gate voltage at a gate of the pass transistor based on a drive voltage. A gain of the output amplification stage is adjustable. Furthermore, the voltage regulator comprises a differential amplification unit to determine the drive voltage in dependence of the output voltage and in dependence of a reference voltage. In addition, the voltage regulator comprises a gain control circuit to adjust the gain of the output amplification stage in dependence of the output current.
    Type: Application
    Filed: October 10, 2016
    Publication date: July 27, 2017
    Inventors: Ambreesh Bhattad, Frank Kronmueller
  • Publication number: 20170177014
    Abstract: A regulator configured to provide at an output node a load current at an output voltage is described. The regulator comprises a pass transistor for providing the load current at the output node. Furthermore, the regulator comprises feedback means for deriving a feedback voltage from the output voltage at the output node. In addition, the regulator comprises a differential amplifier configured to control the pass transistor in dependence of the feedback voltage and in dependence of a reference voltage. The regulator further comprises compensation means configured to determine a sensed current which is indicative of the load current at the output node. Furthermore, the compensation means are configured to adjust an operation point of the regulator in dependence of the sensed current and in dependence of a value of a track impedance of a conductive track which links the output node to a load.
    Type: Application
    Filed: December 16, 2016
    Publication date: June 22, 2017
    Inventors: Hande Kurnaz, Ambreesh Bhattad, Gary Hague, Frank Kronmueller
  • Patent number: 9671804
    Abstract: The present document relates to multi-stage amplifiers, such as linear regulators (e.g. low-dropout regulators). A method and a circuit for reducing leakage current of such multi-stage amplifiers is presented. A voltage regulator is described. The voltage regulator comprises a pass device configured to provide a load current at a regulated output voltage to an output node of the voltage regulator. A source of the pass device is coupled to a first potential of the voltage regulator. Furthermore, the voltage regulator comprises drive circuitry configured to control the pass device via a gate of the pass device, based on a reference voltage and based on a feedback voltage derived from the output voltage. In addition, the voltage regulator comprises leakage reduction circuitry configured to pull-up the gate of the pass device using a second potential; wherein the second potential is higher than the first potential.
    Type: Grant
    Filed: November 19, 2014
    Date of Patent: June 6, 2017
    Assignee: Dialog Semiconductor (UK) Limited
    Inventors: Frank Kronmueller, Ambreesh Bhattad, Burak Dundar
  • Patent number: 9671801
    Abstract: An apparatus and method for a system with improved power supply rejection ratio (PSRR) over a wide frequency range. The improved PSRR is achieved by negating the influence of the parasitic capacitance associated with the bias lines and the introduction of a regulated power supply with embodiments associated with providing a ripple free and regulated supply. With reduction of parasitic capacitance, and providing an ENABLE switch by a pre-regulated supply, the degradation of the PSRR is achieved. The embodiments include both n-channel and p-channel MOSFETs implementations, and a positive and negative regulated power supply voltage. With the combined influence of the utilization of the VREG supply, and the lowering of battery-to-bias line capacitance using design layout and improved floor planning an improved PSRR over a wide frequency distribution is achieved.
    Type: Grant
    Filed: November 6, 2013
    Date of Patent: June 6, 2017
    Assignee: Dialog Semiconductor GmbH
    Inventors: Ambreesh Bhattad, Ludmil Nikolov
  • Patent number: 9651960
    Abstract: Multi-stage amplifiers, such as linear regulators, provide a constant output voltage subject to load transients. The multi-stage amplifier includes a first amplification stage which activates or deactivates a first output stage in response to an input voltage at an input node. The first output stage sources a current at an output node of the multi-stage amplifier from a high potential, when activated. Furthermore, the multi-stage amplifier has a second amplification stage to activate or to deactivate a second output stage in response to the input voltage at the input node. The second output stage sinks a current at the output node of the multi-stage amplifier to a low potential, when activated. The first amplification stage and the second amplification stage activate the first output stage and the second output stage in a mutually exclusive manner.
    Type: Grant
    Filed: November 3, 2015
    Date of Patent: May 16, 2017
    Assignee: Dialog Semiconductor (UK) Limited
    Inventors: Frank Kronmueller, Ambreesh Bhattad
  • Publication number: 20170123443
    Abstract: A voltage regulator is described. It comprises an amplification stage to control a voltage level of a first gain node and of a second gain node in response to an input voltage, to activate a first and a second output stage, respectively. It further comprises the first output stage to source a current at an output node of the voltage regulator from a first potential. The voltage regulator comprises the second output stage to sink a current at the output node to a second potential. The voltage regulator comprises a first operating point control circuit to set the voltage level of the first gain node such that a first maintenance current is sourced by the first output stage; and/or a second operating point control circuit to set the voltage level of the second gain node such that a second maintenance current is sunk by the second output stage.
    Type: Application
    Filed: January 17, 2017
    Publication date: May 4, 2017
    Inventors: Frank Kronmueller, Ambreesh Bhattad
  • Publication number: 20170090495
    Abstract: A linear regulator with a pass device having a first terminal, a second terminal and a drive terminal is presented. The first terminal of the pass device is coupled with the supply voltage of the linear regulator. The second terminal of the pass device is coupled with the output of the linear regulator. A driver stage is coupled with the supply voltage of the linear regulator, and the drive terminal of the pass device drives the pass device with a driving voltage. A compensating circuit compensates for a change in a voltage difference between the drive terminal of the pass device and the supply voltage of the linear regulator.
    Type: Application
    Filed: August 9, 2016
    Publication date: March 30, 2017
    Inventors: Carlos Zamarreno Ramos, Ambreesh Bhattad, Frank Kronmueller
  • Publication number: 20170093350
    Abstract: A multi-stage amplifier, comprising a first amplifier stage is presented. The output of the first amplifier stage is coupled to a first terminal of a capacitor having a controllable capacitance. The input of a second amplifier stage is coupled to the output of the first amplifier stage and the first terminal of the capacitor. The output of the second amplifier stage is coupled to a second terminal of the capacitor and an output of the multi-stage amplifier. The input of a current sensing circuit is coupled with the output of the multi-stage amplifier. A control signal generator is coupled between the output of the current sensing circuit and a control terminal of the capacitor. The control signal generator provides a control signal to the capacitor in order to control or vary the capacitance of the capacitor.
    Type: Application
    Filed: August 9, 2016
    Publication date: March 30, 2017
    Inventors: Carlos Zamarreno Ramos, Ambreesh Bhattad, Frank Kronmueller