Abstract: 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.

Abstract: 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.

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

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

Abstract: 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.

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

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

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Techniques are described that embed a digital assisted regulator with an LDO regulator on a chip without requiring a capacitor external to the chip and to regulate a voltage without undershoot. The digital assisted regulator responds to information regarding operation of the LDO regulator and to a signal that provides advance notification of a load change. When the advance notification signal is received, the digital assisted regulator pulls a circuit's supply voltage up to a chip's incoming supply voltage. When the correct operating voltage has been reached and any undershoot problem removed, the digital assisted regulator balances the current it provides with the current provided by the LDO regulator, to allow a quick response time for other load changes. Also, bandwidth of an LDO regulator may be expanded by use of an advance notice signal to increase bias current of an LDO output device to meet an upcoming load change.

Abstract: 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.

Abstract: 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.

Abstract: 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.