A charge pump driver circuit comprises an output stage and a current generator component. The output stage is arranged to receive at an input node thereof a control current signal and comprises a resistance network coupled between the input node thereof and a reference voltage node and arranged to provide a resistive path through which the control current signal flows. The output stage is arranged to generate at an output node thereof a charge pump control voltage signal based on the voltage level at the input node thereof. The current generator component is arranged to receive an indication of a voltage level of a charge pump output signal, and to generate a feedback current dependent on the voltage level of the output signal, wherein the feedback current is injected into the resistive path of the resistance network through which the control current signal flows.

A circuit for measuring clock jitter includes: an internal signal generator configured to generate an internal clock signal and a single pulse signal, respectively synchronized with an input clock signal; a plurality of delay units being connected in series with each other and configured to generate respective delayed clock signals; a plurality of latch circuits configured to latch the single pulse signal in synchronization with the respective delayed clock signals, and output sampling signals; and a count sub-circuit configured to output a count value resulting from counting a number of active sampling signals of the sampling signals.

A circuit for measuring clock jitter includes: an internal signal generator configured to generate an internal clock signal and a single pulse signal, respectively synchronized with an input clock signal; a plurality of delay units being connected in series with each other and configured to generate respective delayed clock signals; a plurality of latch circuits configured to latch the single pulse signal in synchronization with the respective delayed clock signals, and output sampling signals; and a count sub-circuit configured to output a count value resulting from counting a number of active sampling signals of the sampling signals.

A tuning array selection circuit, together with a decoder and a voltage controlled oscillator (VCO), can be employed to overcome some disadvantages of previous methods of phase locked loops. For example, a VCO can include a coarse tuning array and a fine tuning array. A coarse tuning array can be used to tune a VCO to generate a signal within a wide frequency range. A fine tuning array can be used to tune a VCO to generate a signal within a narrow frequency range. In one embodiment, the narrow frequency range is within the wide frequency range. The tuning array selection circuit can coordinate selection of appropriate fine tuning devices and narrow tuning devices to reduce transition jitter and the risk of fail locking of phase locked loops.

A system includes a local oscillator (LO) signal generation circuit, a receiver (RX) circuit, and a calibration circuit. The LO signal generation circuit generates an LO signal according to a reference clock, and includes an active oscillator that generates the reference clock. The active oscillator includes at least one active component. The RX circuit generates a processed RX signal by processing an RX input signal according to the LO signal. The calibration circuit checks a signal characteristic of the processed RX signal by detecting if a calibration tone exists within a receiver bandwidth, set a frequency calibration control output in response to the calibration tone being not found in the receiver bandwidth, and output the frequency calibration control output to the LO signal generation circuit. The LO signal generation circuit adjusts an LO frequency of the LO signal in response to the frequency calibration control output.

A system includes a local oscillator (LO) signal generation circuit, a receiver (RX) circuit, and a calibration circuit. The LO signal generation circuit generates an LO signal according to a reference clock, and includes an active oscillator that generates the reference clock. The active oscillator includes at least one active component. The RX circuit generates a processed RX signal by processing an RX input signal according to the LO signal. The calibration circuit checks a signal characteristic of the processed RX signal by detecting if a calibration tone exists within a receiver bandwidth, set a frequency calibration control output in response to the calibration tone being not found in the receiver bandwidth, and output the frequency calibration control output to the LO signal generation circuit. The LO signal generation circuit adjusts an LO frequency of the LO signal in response to the frequency calibration control output.

Provided are a clock conversion device, a test system including the same, and a method of operating the test system. The clock conversion device includes a first clock generator configured to receive a first input clock signal from test logic and generate a first clock signal of which a frequency is multiplied and a phase is locked; a clock conversion circuit configured to receive the first clock signal and generate one or more second clock signals by converting at least one clock characteristic of the first clock signal; and an output selector configured to output any one of the first clock signal and the one or more second clock signals as an output clock signal, wherein the clock conversion device is configured to provide the output clock signal to a device under test (DUT).

A semiconductor device includes a clock generating circuit and a jitter measurement circuit. The clock generating circuit is input with a control value for changing a cycle of the clock thereof. The jitter measurement circuit has a first logic circuit operated with using an output clock of the clock generating circuit as an input and a first delay element, and is configured to output the presence/absence of a jitter of the clock generating circuit.

A frequency measurement circuit includes a counter circuit to receive a first digitally-controlled oscillator (DCO) clock signal corresponding to a first DCO input codeword and a measurement signal. The counter circuit is responsive to the measurement signal to generate a count representing a measured frequency of the first DCO clock signal. A control circuit is configured to selectively adjust a parameter of the measurement signal for generating a second count of a second DCO clock signal corresponding to a second DCO codeword. The control circuit selectively adjusts the parameter based on a received control signal.

A frequency measurement circuit includes a counter circuit to receive a first digitally-controlled oscillator (DCO) clock signal corresponding to a first DCO input codeword and a measurement signal. The counter circuit is responsive to the measurement signal to generate a count representing a measured frequency of the first DCO clock signal. A control circuit is configured to selectively adjust a parameter of the measurement signal for generating a second count of a second DCO clock signal corresponding to a second DCO codeword. The control circuit selectively adjusts the parameter based on a received control signal.