Qualcomm Incorporated

University of California

Marzio Pedrali-Noy

Ashwin Raghunathan

Sameer Wadhwa

Mustafa Keskin

Charles James Persico

Sang Wook Park

Martin Saint-Laurent

Xuhao Huang

Jeffrey Mark Hinrichs

Xiaohong Quan

Deepti Vijayalakshmi Sriramagiri

Michael Drop

Raghu Sankuratri

Zhengzheng Wu

Edwin Jose

Yi-Hung Tseng

William W Moses

Deping Huang

Eric Beuville

Chao Song

Ian Galton

Ashok Swaminathan

Xufeng Chen

Sungmin Ock

Christian Venerus

Yuhe Wang

Ashwin Ragunathan

Sylvain M Colin

Jun Young Park

Sang-Wook Park

Deepti Sriramagiri

An apparatus is disclosed for making circuitry with passive fundamental components more robust. In example implementations, an apparatus includes at least one passive fundamental component and at least one redundant passive fundamental component. The apparatus also includes fault tolerant circuitry coupled to the at least one passive fundamental component and the at least one redundant passive fundamental component. The fault tolerant circuitry includes fault detection circuitry configured to detect a fault of the at least one passive fundamental component. The fault tolerant circuitry also includes component repair circuitry configured to disconnect the at least one passive fundamental component based on the fault.

Robust circuitry for passive fundamental components

An apparatus is disclosed for robust transistor circuitry. In example implementations, an apparatus includes a current mirror and fault handler circuitry that is coupled to the current mirror. The current mirror includes a core transistor having a control terminal, a first transistor, and a second transistor. The first transistor has a control terminal that is coupled to the control terminal of the core transistor. The second transistor has a control terminal that is coupled to the control terminal of the core transistor. The fault handler circuitry is configured to select the first transistor or the second transistor to provide a mirrored current of the current mirror.

Robust transistor circuitry

An apparatus including: a phase lock loop (PLL), including: a phase detector and loop pass filter (PD/LF), including: a phase/frequency detector including a first input configured to receive a reference signal, and a second input configured to receive a feedback signal, and an output configured to produce an output signal based on the reference and feedback signals; a first capacitor; and a charge pump, including: a charging path configured to generate a charging current to charge the first capacitor based on the output signal; and a discharging path including a first resistor configured to discharge the first capacitor.

High gain low power phase detector and loop filter for phase lock loop (PLL)

A sub-ranging time-to-digital converter (TDC) is disclosed that includes two ring oscillators for determining a time difference between two clock edges.

Clock screening with programmable counter-based clock interface and time-to-digital converter with high resolution and wide range operation

A process-invariant RC circuit is formed by patterning a metal layer using the same mask pattern to form a metal layer resistor and a metal layer capacitor. The same mask pattern results in the metal layer resistor and the metal layer capacitor each having a plurality of longitudinally-extending fingers having the same width and separation.

Process-invariant resistor and capacitor pair

A subranging time-to-digital converter (TDC) is disclosed that includes two ring oscillators for determining a time difference between two clock edges.

Methods, systems, and circuits for providing compensation for voltage variation are disclosed. A system includes: a voltage comparator configured to assert a control signal in response to detecting that one or more of power supply voltages droops below a threshold amount; a phase locked loop (PLL) configured to divide an output frequency for the PLL in response to the assertion of the control signal; a plurality of voltage sensors corresponding to the plurality of power supply voltages, the voltage sensors configured to output respective digital signals indicative of a voltage level of its corresponding power supply voltage; and a control circuit configured to control an oscillator frequency in the PLL during the open-loop mode responsive to the respective digital signals.

Circuits and methods providing clock frequency adjustment in response to supply voltage changes

Certain aspects of the present disclosure support a method and apparatus for fast frequency throttling and re-locking in a phase-locked loop (PLL) device. Aspects of the present disclosure present a method and apparatus for operating in an open loop control (OLC) mode of the PLL device for generating a periodic signal. During the OLC mode, clocking of circuitry interfaced with a digitally-controlled oscillator (DCO) of the PLL device can be disabled. A PLL output frequency associated with the periodic signal generated by the DCO can be controlled directly through a digital control word input into the DCO.

Fast frequency throttling and re-locking technique for phase-locked loops

A method for data synchronization is provided according to certain embodiments. The method comprises receiving data, a data clock signal, and a clean clock signal, sampling the data using the data clock signal, synchronizing the sampled data with the clean clock signal, and outputting the synchronized sampled data. The method also comprises tracking a phase drift between the data clock signal and the clean clock signal, and pulling in the output of the synchronized sampled data by one clock cycle of the clean clock signal if the tracked phase drift reaches a first value in a first direction.

Low latency synchronization scheme for mesochronous DDR system

In one embodiment, a memory interface comprises a cleanup phase-locked loop (PLL) configured to receive a reference clock signal, and to generate a clean clock signal based on the reference clock signal. The memory interface also comprises a synchronization circuit configured to receive data, a data clock signal, and the clean clock signal, wherein the synchronization circuit is further configured to sample the data using the data clock signal, and to synchronize the sampled data with the clean clock signal.

Temperature-independent delay elements and oscillators are disclosed. In one design, an apparatus includes at least one delay element, a bias circuit, and a current source. The delay element(s) receive a charging current from the current source and provide a delay that is dependent on the charging current. Each delay element may be a current-starved delay element. The delay element(s) may be coupled in series to implement a delay line or in a loop to implement an oscillator. The bias circuit controls generation of the charging current based on a function of at least one parameter (e.g., a switching threshold voltage) of the at least one delay element in order to reduce variations in delay with temperature. The current source provides the charging current for the delay element(s) and is controlled by the bias circuit.

Temperature-independent oscillators and delay elements

A circuit for detecting a voltage change is described. The circuit includes a supply insensitive pulse generator that generates a pulse signal. The circuit also includes a time-to-digital converter coupled to the supply insensitive pulse generator. The time-to-digital converter generates a digital signal based on the pulse signal and a voltage. The circuit also includes a controller coupled to the time-to-digital converter that detects a voltage change based on the digital signal.

Circuit for detecting a voltage change using a time-to-digital converter

An injection-locked oscillator circuit includes a master oscillator, a slave oscillator, and an injection lock control circuit. The slave oscillator is decoupled from the master oscillator (for example, due to an unlock condition). When the slave is free running, its oscillating frequency is adjusted (for example, as a function of a supply voltage). After an amount of time, the slave is to be relocked to the master (for example, due the unlock condition no longer being present). The slave oscillating frequency is made to be slightly lower than the master oscillating frequency. The slave is then only recoupled to the master upon detection of an opposite-phase condition between the master oscillator output signal and the slave oscillator output signal. By only recoupling the slave to the master during opposite-phase conditions, frequency overshoots in the slave oscillating frequency are avoided that may otherwise occur were the recoupling done during in-phase conditions.

Injection-locking a slave oscillator to a master oscillator with no frequency overshoot

Closed-loop techniques for adjusting the duty cycle of a cyclical signal, e.g., a clock signal, to approach a target value. In an exemplary embodiment, a charge pump is coupled to a charge and sample module, which drives a de-skew circuit in a negative feedback loop. The charge and sample module couples the charge pump to the integration capacitor during two of four successive phases, and also couples the integration capacitor to sampling capacitors during the other two of the four successive phases. The voltages across the sampling capacitors may be used to control the de-skew circuit, which adjusts the duty cycle of a cyclical signal to be adjusted.

Duty cycle correction circuitry

A supply-regulated VCO exhibits reduced or no supply sensitivity peaking. The VCO includes an oscillator whose supply current is regulated to control the oscillating frequency of the oscillator. A VCO input signal controls the supply current so that there is a relationship between the input signal and the oscillator output frequency. Power supply noise that might otherwise affect oscillator operation is shunted from a supply current input lead of the oscillator to ground by a bypass capacitor. In one example, an auxiliary circuit supplies an auxiliary supply current to the oscillator, thereby reducing the amount of supply current a supply regulation control loop circuit must supply. In another example, a supply regulation control loop circuit supplies a control current to a main oscillator, but the bypass capacitor is not coupled to this oscillator but rather is coupled to a slave oscillator that is injection locked to the main oscillator.

Growing community of inventors

San Diego, CA, United States of America

Marzio Pedrali-Noy