摘要:
A differential clock signal gating method and system is provided, wherein a clock buffer circuit control path develops a clock gating signal with a timing relationship to a clock signal. The clock gating signal gates a buffer on the clock buffer circuit controlled path in communication with the clock signal responsive to a first clock signal pulse negative half. The buffer provides second and successive clock signal pulses occurring immediately and sequentially after the first clock signal pulse as a buffer clock signal output to a second buffer stage in a second stage clock path, each having the nominal clock amplitude and the nominal clock pulse width of the clock signal without jitter.
摘要:
A differential clock signal gating method and system is provided, providing a clock gating signal with a timing relationship to a clock signal and a differential pair current to a buffer differential pair load element. Switching the differential pair current from the load element to a buffer differential pair responsive to a gating signal pulse, the gating signal pulse correlated to a first clock signal pulse, the buffer differential pair buffers a second clock signal pulse occurring immediately and sequentially after the first clock signal pulse and successive clock signal pulses as a buffer clock signal output, the output comprising a plurality of pulses each having the clock signal amplitude and the clock signal pulse width.
摘要:
A circuit design, method, and system for tracking VCO calibration without requiring an over-designed divider as in conventional implementation. A filter reset component is added to the inputs of the VCO. A process step is added to the calibration mechanism/process that shorts the filter nodes and thus centers the frequency of the VCO before stepping from one frequency band to the next.
摘要:
Aspects for reducing jitter in a PLL of a high speed serial link are described. The aspects include examining at least one parameter related to performance of a voltage controlled oscillator (VCO) in the PLL, and controlling adjustment of a supply voltage to the VCO based on the examining. A regulator control circuit performs the examining and controlling.
摘要:
Substantially-accurate calibration of output impedance of a device-under-test (DUT) to within a predetermined range of allowable impedance. The DUT is part of a source series terminated (SST) serial link transmitter, in which two branches of parallel transistors each provide an impedance value when particular transistors of the parallel branch are turned on. The impedance value is added to a series-connected resistor to provide the output impedance. The DUT consists of one branch of parallel transistors in series with a resistor. Output impedance of the DUT is compared to the resistance of a reference resistor, and the comparator provides a control signal based on whether the output impedance falls within the pre-set percentage variance of the reference resistance. The control signal is processed by a FSM (finite state machine) that individually turns on or off the transistors within the parallel branch until the DUT impedance value falls within the desired range.
摘要:
A self-adaptive voltage regulator for a phase-locked loop is disclosed. The phase-locked loop includes a phase detector, a charge pump, a low pass filter, and a voltage control oscillator, wherein the low pass filter inputs a control voltage to a voltage controlled oscillator for generation of an output clock. According to the method and system disclosed herein, the self-adaptive voltage regulator is coupled to an output of the low pass filter for sensing the control voltage during normal operation of the phase-locked loop, and for dynamically adjusting the supply voltage, which is input to the voltage controlled oscillator in response to the control voltage, such that the phase-locked loop maintains the control voltage within a predefined range of a reference voltage.
摘要:
A method for providing quality control on wafers running on a manufacturing line is disclosed. The resistances on a group of manufacturing test structures within a wafer running on a wafer manufacturing line are initially measured. Then, an actual distribution value is obtained based on the result of the measured resistances on the group of manufacturing test structures. The difference between the actual distribution value and a predetermined distribution value is recorded. The predetermined distribution value is previously obtained based on a ground rule resistance. Next, the resistances on a group of design test structures within the wafer are measured. The measured resistances of the group of design test structures are correlated to the measured resistances of the group of manufacturing test structures in order to obtain an offset value. The resistance of an adjustable resistor circuit within the wafer is then adjusted accordingly, and subsequent wafers running on the wafer manufacturing line are also adjusted according to the offset value.