Taiwan Semiconductor Manufacturing Comp. Ltd.

Ya-Tin Chang

Ruey-Bin Sheen

Chih-Hsien Chang

Mao-Hsuan Chou

Tsung-Hsien Tsai

Cheng-Hsiang Hsieh

An automatic gain adjustor for a hybrid oscillator can be employed to overcome the frequency limitations of hybrid phase lock loops (PLLs). For example, an automatic gain adjustor for a hybrid oscillator can include a hybrid oscillator that is configured to receive a coarse tuning signal and a gain adjustment signal and generate an output signal with any frequency within the specified frequency range of the hybrid PLL. The automatic gain adjustor for a hybrid PLL may further include a fine tuning array that receives one or more fine tuning selection signals and generates a gain adjustment signal that is received by the hybrid oscillator. The fine tuning array generates a gain adjustment signal to adjust the gain of the hybrid oscillator according to an operating frequency range of the hybrid oscillator.

Automatic hybrid oscillator gain adjustor circuit

A circuit and a method for adjusting a periodic input signal are provided. The circuit includes a duty cycle calibration (DCC) device, a phase adjusting device, and a duty cycle measurement (DCM) device. The DCC device is configured to generate a first signal and a second signal in response to the periodic input signal. The first signal and the second signal have different phases. The phase adjusting device is configured to receive the first signal and the second signal to generate a third signal by combining the first signal and the second signal based on a selection signal. The DCM device is configured to measure and adjust a duty cycle of the third signal so that the selection signal is adjusted to generate a periodic output signal. A frequency of the periodic output signal is twice that of the periodic input signal.

Circuit and method for duty cycle adjustment

A device includes a phase detector circuit, a charge pump circuit, a sample and hold circuit, a comparator, and a controller. The phase detector circuit detects a clock skew between a reference signal and an input signal. The charge pump circuit translates the clock skew into a voltage. A sample and hold circuit samples the voltage, at a first time, and maintain the sampled voltage until a second time. The comparator (i) detects a loop gain associated with the input signal based on the sampled voltage and the voltage at the second time and (ii) outputs a loop gain signal for adjustment of the input signal. The controller is coupled to the phase detector, the comparator, and the sample and hold circuit. The controller generates a plurality of control signals for automatically controlling operation of the phase detector, the comparator, and the sample and hold circuit.

Loop gain auto calibration using loop gain detector

Digital delay lock circuits and methods for operating digital delay lock circuits are provided. A phase detector is configured to receive first and second clock signals and generate a digital signal indicating a relationship between a phase of the first clock signal and a phase of the second clock signal. A phase accumulator circuit is configured to receive the digital signal and generate a phase signal based on values of the digital signal over multiple clock cycles. A decoder is configured to receive the phase signal and generate a digital control word based on the phase signal. A delay element is configured to receive the digital control word. The delay element is further configured to change the relationship between the phase of the first clock signal and the phase of the second clock signal by modifying the phase of the second clock signal according to the digital control word.

Delay lock loop circuits and methods for operating same

A method and apparatus of generating precision phase skews is disclosed. In some embodiments, a phase skew generator includes: a charge pump having a first mode of operation and a second mode of operation, wherein the first mode of operation provides a first current path during a first time period, and the second mode of operation provides a second current path during a second time period following the first time period; a sample and hold circuit, coupled to a capacitor, and configured to sample a voltage level of the capacitor at predetermined times and provide an output voltage during a third time period following the second time period; and a voltage controlled delay line, coupled to the sample and hold circuit, and having M delay line stages each configured to output a signal having a phase skew offset with respect to preceding or succeeding signal.

Method and apparatus for precision phase skew generation

A system, a method and a built-in phase noise measurement apparatus are introduced. The built-in phase noise measurement apparatus includes a first DLL and a TDC, in which the first DLL circuit controls a delay of a first signal to generate a second signal based on a control code, tune the control code until a phase of the second signal is aligned to a phase of a reference clock signal, and record a value of the control code when the phase of the second signal is aligned to the phase of the reference clock signal. The DLL circuit controls the delay of the first signal based on the value of the control code after the phase of the second signal is aligned to the phase of the reference clock signal. The TDC determines the phase noise of the first signal based on the reference clock signal and the second signal.

Apparatus, system and method for phase noise measurement

An apparatus and method for providing a phase noise built-in self test (BIST) circuit are disclosed herein. In some embodiments, a method and apparatus for forming a multi-stage noise shaping (MASH) type high-order delta sigma (&#x394;&#x3a3;) time-to-digital converter (TDC) are disclosed. In some embodiments, an apparatus includes a plurality of first-order &#x394;&#x3a3; TDCs formed in an integrated circuit (IC) chip, wherein each of the first-order &#x394;&#x3a3; TDCs are connected to one another in a MASH type configuration to provide the MASH type high-order &#x394;&#x3a3; TDC, wherein the MASH type high-order &#x394;&#x3a3; TDC is configured to measure the phase noise of a device under text (DUT).

Built-in self test circuit for measuring phase noise of a phase locked loop

A method and apparatus of generating precision phase skews is disclosed. In some embodiments, a phase skew generator includes: a charge pump having a first mode of operation and a second mode of operation, wherein the first mode of operation provides a first current path during a first time period, and the second mode of operation provides a second current path during a second time period following the first time period, a sample and hold circuit, coupled to a capacitor, and configured to sample a voltage level of the capacitor at predetermined times and provide an output voltage during a third time period following the second time period; and a voltage controlled delay line, coupled to the sample and hold circuit, and having M delay line stages each configured to output a signal having a phase skew offset with respect to preceding or succeeding signal.

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Hsinchu, Taiwan

Ya-Tin Chang