Freescale Semiconductor,inc.

Nxp B.v.

Nxp Usa, Inc.

Divya Tripathi

Sanjay Kumar Wadhwa

Qadeer Ahmad Khan

Saurabh Goyal

Kulbhushan Misri

Krishna Thakur

Siddhartha Gk

Deependra Kumar Jain

Anubhav Srivastava

Sadique Mohammad Iqbal

John M Pigott

Alvin Leng Sun Loke

Parul K Sharma

Anil Kumar Gottapu

Jaideep Banerjee

Pragya Priya Malakar

Kailash Dhiman

Manish Kumar Upadhyay

A low current, adaptively-biased switched resistor digital-to-analog converter (RDAC) circuit, method and apparatus are provided with a coarse trim ladder and a fine trim ladder connected with a plurality of NFET switches to generate an output reference voltage from an input supply voltage, where the bulk semiconductor substrate regions for the NFET switches in at least the fine trim ladder are driven by a unity gain buffer which is connected in feedback to receive the output reference voltage and to generate a buffered reference voltage which is directly connected to bulk semiconductor regions of the NFET switches, thereby providing a low current, low circuit area solution with reduced leakage current and temperature variation.

RDAC ladder with adaptive biasing to reduce the reference variation across temperature

Systems and methods for providing temperature compensation in oscillators circuits are discussed. In various embodiments, these systems and methods may be implemented in technologies where only resistors with the same type (positive or negative) of temperature coefficients of resistance are available. For example, in some implementations, an oscillator circuit may include a voltage generator coupled to an input terminal of a common gate amplifier through a first resistor, and a frequency-to-voltage converter coupled to another input terminal of the common gate amplifier through a second resistor, where the second resistor may be configured to reduce a frequency variation of the oscillator circuit in response to temperature changes.

Temperature compensation in oscillator circuits

An integrated circuit (IC) includes one or more active transistors and multiple series-coupled dummy transistors. The dummy transistors are coupled between two active transistors and/or at the ends of each active transistor. When the dummy transistors are coupled between two active transistors, apart from two conductive regions that are coupled to two active transistors, each remaining conductive region of the dummy transistors is maintained in a floating state to control a leakage current between the two active transistors. Similarly, when the dummy transistors are coupled at an end of one active transistor, apart from one conductive region that is coupled to the active transistor, each remaining conductive region of the dummy transistors is maintained in the floating state to control a leakage current between the active transistor and the dummy transistors.

System for controlling leakage current in integrated circuits

A self-biased, closed loop, low current free running oscillator clock generator method and apparatus are provided with a current mode comparator connected to a trimming resistor and configured to compare an internally generated voltage reference Vsignal to a voltage feedback signal V, where the current mode comparator comprises a common gate amplifier connected to a current mirror circuit in a negative self-biased closed loop to generate a control current signal for controlling a current controlled oscillator to produce an output clock signal having a clock frequency based on the control current signal, where a frequency-to-voltage converter is connected in a feedback path to receive the output clock signal and is configured to produce the voltage feedback signal Vfor input to the current mode comparator, wherein the clock frequency of the output clock signal is tuned to a nominal locked output frequency fby the trimming resistor.

Self-biased, closed loop, low current free running oscillator

An integrated circuit including a functional circuit, a tuning circuit, and a control circuit is provided. The functional and control circuits generate an output signal and a digital code, respectively. The tuning circuit tunes the functional circuit based on the digital code to control an attribute of the output signal. The digital code is iteratively adjusted such that the attribute of the output signal is maintained within a predefined range. When the digital code corresponds to a cliff value, the digital code for a subsequent iteration is adjusted by a non-unit offset value such that a difference between the attribute for the cliff value and for the subsequent digital code is within a tolerance limit. The digital code is indicative of coarse and fine parameters, and for each value of the coarse parameter, the cliff value corresponds to the lowest or highest value of the fine parameter.

System and method for controlling tuning in electronic circuitries

A level shifter includes a control circuit and a bias circuit. The control circuit receives a bias voltage, a first signal associated with a first voltage domain, and supply voltages associated with a second voltage domain, and outputs a second signal that is associated with the second voltage domain. The bias circuit generates the bias voltage that is indicative of the duty cycle of the second signal, and provides the bias voltage to the control circuit to control the duty cycle of the second signal. The duty cycle of the second signal is controlled such that a difference between a duty cycle of the first signal and an inverse of the duty cycle of the second signal is less than a tolerance limit.

Level shifter

A soft-start circuit for a voltage regulator includes a comparator and a delay circuit. The comparator compares an output voltage, that is generated by the voltage regulator, and a reference voltage to generate a comparison signal. Further, the delay circuit receives the reference voltage and a control signal that is outputted based on the comparison signal, and outputs and provides another reference voltage to the voltage regulator. During a start-up of the voltage regulator, the reference voltage outputted by the delay circuit is a delayed version of the reference voltage received by the delay circuit. Thus, the soft-start circuit mitigates an overshoot of the output voltage during the start-up. Further, on completion of the start-up, the reference voltage outputted by the delay circuit is equal to the reference voltage received by the delay circuit.

Soft-start circuit for voltage regulator

A level shifter includes a pull-down circuit, a pull-up circuit, a protection circuit, and an output generator. The pull-down circuit is configured to receive input voltages, and generate bias voltages. The input voltages are associated with a voltage domain. The pull-up circuit is configured to receive a supply voltage and generate control voltages. The protection circuit is configured to receive reference voltages, and control the generation of the bias voltages and the control voltages. The output generator is configured to receive at least one of the reference voltages, and at least one of the bias voltages and the control voltages, and generate output voltages that are able to reach minimum and maximum voltage levels of another voltage domain. Further, the output voltages remain unaffected by variations in process, voltage, and temperature.

A low voltage differential signaling circuit includes an output driver circuit configured to provide a differential signal pair based on a first signal and a second signal. A peak detect circuit is coupled to receive the differential signal pair and configured to provide a feedback signal based on the differential signal pair and the first and second signals. An amplifier circuit has a first input coupled to the peak detect circuit, a second input coupled to receive a reference voltage, and an output coupled to provide a bias voltage to the output driver circuit.

Low voltage differential signaling circuit

A power-on-reset (POR) circuit for a system-on-chip (SOC) includes a biased switching element having a source, drain, and gate, with the source being connected to a supply voltage and the drain and gate being connected to a control line. The POR circuit further includes a first delay switching element having a source connected to a reduced supply voltage, a gate connected to the control line, and a drain, and an inverter having an input and an output, with the input being connected to the drain of the first delay switching element. The inverter includes a first CMOS inverter coupled between the supply voltage and a reference voltage. A first capacitor is coupled between the inverter input and the reference voltage. A second capacitor coupled between the inverter input and an output of the first CMOS inverter.

Low variation power-on-reset circuit

A current-starved inverter circuit includes first and second current-mirror circuits, first and second transistors, a detector, and a current-booster. The first and second transistors receive a first source current and a first sink current from the first and second current-mirror circuits, respectively, and an input voltage signal, and generate an inverted input voltage signal (an output voltage signal). The detector generates a first detection signal when the output voltage signal exceeds a first threshold value and a second detection signal when the output voltage signal is less than a second threshold value. The current-booster, which is connected to the detector, receives the first and second detection signals and provides a second source current and a second sink current to the first and second transistors to pull-up and pull-down a voltage level of the output voltage signal, respectively.

Current-starved inverter circuit

A compensation circuit and a method that compensates for process, voltage and temperature (PVT) variations in an integrated circuit that includes functional modules. The compensation circuit includes a signal generator, a first code generator, a second code generator, and a mapping module. The signal generator generates a first signal and a second signal depending on aligned process corner, voltage and temperature variations and skewed process corner variations respectively. The first code generator receives the first signal, and generates a first calibration code. The second code generator receives the second signal, and generates a second calibration code. The mapping module provides the first and second calibration codes for compensating for the aligned process corner, voltage and temperature variations and the skewed process corner variations associated with the functional modules respectively.

PVT variation detection and compensation circuit

A compensation circuit and a method for detecting and compensating for process, voltage, and temperature (PVT) variations in an integrated circuit. The integrated circuit includes plural logic modules that include PMOS transistors and NMOS transistors. The compensation circuit includes first and second functional modules, which generate first and second calibration signals. The first and the second calibration signals are used to compensate for the PVT variations in PMOS and NMOS transistors.

A differential receiver circuit receives a differential input signal including first and second input signals (DP, DM) and generates a single-ended output signal. The receiver circuit includes first and second comparators that receive the differential input signal and generate respective first and second differential output signals. A current summer is connected to the first and second comparators and receives the first and second differential output signals and generates a third differential output signal. A differential to single-ended converter is connected to the current summer and receives the third differential output signal and generates the single-ended output signal. The differential input signal varies from a ground voltage level to an external reference voltage level (VUSB), while the first and second comparators are made with devices that operate at an internal reference voltage level that is lower than the external reference voltage level.

Differential receiver circuit

A compensation circuit and a method for compensating for process, voltage and temperature (PVT) variations in an integrated circuit (IC). The IC includes several functional modules, each of which includes a set of functional units, and generates an output signal in response to an input signal. The compensation circuit includes a code generator and a logic module. The code generator generates a digital code for each functional unit. The digital codes are based on phase differences between the input signal and the output signal. The logic module generates calibration codes based on the digital codes. The calibration codes compensate for the PVT variations in the corresponding functional units.

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Bhopal, India

Divya Tripathi