According to one embodiment, a semiconductor device includes an input/output circuit to which a signal is input or from which a signal is output; a first terminal connected to a power line of the input/output circuit; a second terminal connected to the power line; a resistance element connected between the second terminal and the power line; and a first capacitance element connected between the second terminal and a ground terminal.

Embodiments include systems and methods for calibrating clocking circuits for improved jitter performance. Embodiments operate in context of a clocking circuit coupled with a transceiver system that has a receiver that tracks a recovered clock phase according to a tracking code. For example, candidate configurations can be identified, each corresponding to a different respective combination of parameter values for programmable clocking circuit parameters. For each candidate configuration, embodiments can configure the clocking system accordingly, and can sample the tracking code over a sample window to measure a tracking code spread for the candidate configuration. The clocking circuit can be programmed according to which of the candidate configurations manifested a minimum tracking code spread, thereby effectively configuring the clocking circuit for minimum jitter generation and optimizing jitter performance of the transceiver.

An apparatus is provided which comprises: an oscillator to generate a first clock having a first frequency; a divider coupled to the oscillator, wherein the divider is to generate a second clock having a second frequency; and a current reference generator comprising a switched capacitor circuitry which is to receive the second clock directly or indirectly.

A clock and data recovery circuit with jitter tolerance enhancement is provided. The CDR circuit includes: a bang-bang phase detector, a digital filter, a digitally controlled oscillator, and an adaptive loop gain control circuit. The CDR circuit detects a loop bandwidth variation and adjusts the loop bandwidth of CDR circuit by adjusting proportional path and integral path gain factors of the digital filter of the CDR circuit. The loop gain controller uses two methods to adjust the loop gain in CDR circuit: bang-bang adjusting method and linear adjusting method.

A magnitude difference between intrinsic positive and negative current components forming a PLL's charge pump output current is determined by simultaneously outputting the intrinsic positive and negative pump current components, and incrementally increasing a bias current added to one of the intrinsic current components (e.g., such that the total positive current component is gradually increased). Calibration control voltages generated by the calibration pump output current are measured to determine when magnitudes of the adjusted (e.g., positive) current component and the non-adjusted/intrinsic (e.g., negative) current component are equal, and the bias current amount required to achieve equalization is stored as a digital converter code. During subsequent normal PLL operations, the digital converter code is utilized to control the charge pump such that the magnitude of the positive current component is adjusted by the bias current amount such that the positive and negative current components are matched.

A phase locked loop arrangement (1) beamforming comprises two or more phase locked loops. The loops include a phase comparator (21, 22) and an adjustable charge pump arrangement (31, 32) having a loop filter (51, 52) and charge pump current source (41, 42) with an adjustment input (.sub.adj) connected to the loop filter (51, 52) to inject an adjustable charge pump current into the loop filter. A constant current source (71, 72) is configured to inject a first predetermined charge current into the loop filter (51, 52). The adjustable charge pump arrangements (31, 32) are connected to the respective phase comparators (21, 22) to provide a voltage control signal (vctrl) to an oscillator (61, 62) of the respective phase adjustable phase locked loop (11, 12) in response to the respective control signal (up, down) and to generate a phase deviation between the first and one of the at least one second oscillator signals (f.sub.osc1, f.sub.osc2) based on an adjustment signal applied to the adjustment input (.sub.adj).

An apparatus comprises a digitally controlled circuit having a variable capacitance and a controller configured to adjust a magnitude of the variable capacitance of the digitally controlled circuit. The digitally controlled circuit comprises a plurality of gain elements, the plurality of gain elements comprising one or more positive voltage-to-frequency gain elements and one or more negative voltage-to-frequency gain elements. The controller is configured to adjust the magnitude of the capacitance by adjusting the gain provided by respective ones of the gain elements in an alternating sequence of the positive voltage-to-frequency gain elements and the negative voltage-to-frequency gain elements.

The present disclosure discloses a multi-standard performance reconfigurable I/Q orthogonal carrier generator. The generator may implement a continuously covered I/Q carrier output of 0.1-5 GHz and continuously covered differential signal outputs of 5-10 GHz and 1.5-3 GHz by means of reasonable frequency assignment; also, carrier signals under various frequencies with different loop bandwidths, different phase noises, different power consumption levels and different locking times can be generated by configuring a programmable charge pump (102), a loop filter (103) parameter, a multi-path voltage-controlled oscillator (104) and a first multiplexer (105) corresponding thereto, a five-stage-division-by-two frequency division link (109) and a corresponding second multiplexer (110) and third multiplexer (112), so as to implement generation of a multi-standard performance reconfigurable I/Q orthogonal carrier.

A transceiver may include a reception (Rx) radio frequency (RF) part configured to process a received signal, a transmission (Tx) RF part configured to process a transmitted signal, and a phase lock loop (PLL) configured to provide a reception frequency to the reception RF part and provide a transmission frequency to the transmission RF part. The PLL may be controlled according to whether the reception RF part or the transmission RF part is on. In addition, a transceiver may include quenching waveform generator (QWGs) to control quenching waveforms of the RF parts corresponding to a plurality of antennas. The quenching waveforms may be generated respectively by VCOs operating at a same frequency. The QWGs may control the VCOs such that the quenching waveforms do not overlap.

A magnitude difference between intrinsic positive and negative current components forming a PLL's charge pump output current is determined by simultaneously outputting the intrinsic positive and negative pump current components, and incrementally increasing a bias current added to one of the intrinsic current components (e.g., such that the total positive current component is gradually increased). Calibration control voltages generated by the calibration pump output current are measured to determine when magnitudes of the adjusted (e.g., positive) current component and the non-adjusted/intrinsic (e.g., negative) current component are equal, and the bias current amount required to achieve equalization is stored as a digital converter code. During subsequent normal PLL operations, the digital converter code is utilized to control the charge pump such that the magnitude of the positive current component is adjusted by the bias current amount such that the positive and negative current components are matched.