Realtek Semiconductor Inc.

Chuan-Ping Tu

Chun-Ta Ho

Fangjie Yang

A phase interpolator includes a current generating circuit, a current controlling circuit and a signal generating circuit, wherein the current generating circuit is arranged to generate a current; and the current controlling circuit is arranged to generate a control signal to the current generating circuit to control a current value of the current. The signal generating circuit includes a capacitor, wherein the signal generating circuit generates a phase interpolation signal by using the capacitor to receive the current, wherein a phase of the phase interpolation signal is varied according to the current.

Phase interpolator and clock generating method

A background self-calibrated DAC is presented. A virtual-short theory, applicable to input/output terminals of an operational amplifier, is periodically employed so as to self-calibrate a current source serially connected with an equivalent resistor, and the DAC using the same. The DAC does not require an additional self-calibration period, and digital-to-analog conversion thereof can be realized in merely a small amount of die area. Correspondingly, a compact and high-speed current steering DAC can be realized.

Self-calibrated current source and DAC using the same and operation method thereof

A current feedback circuit is used in the source follower. The source follower includes a first MOS transistor and a current mirror. The first MOS transistor has a gate receiving an inputting signal and a source outputting an output signal. A drain current flows through the first MOS transistor. The current mirror generates the drain current according to an adding current. The current feedback circuit is used for stabilizing the drain current to a constant value substantially. The current feedback circuit includes a passive component and an operational amplifier. The passive component has a first end and a second end, which has an error voltage when a corresponding current flows through the passive component. The magnitude of the corresponding current changes with the magnitude of the drain current. The operational amplifier outputs a reference signal to adjust the adding current according to the error voltage and a reference voltage.

Source follower and current feedback circuit thereof

An amplifier with increased bandwidth by current injection and a method thereof. The amplifier includes an input stage for receiving a first input signal, a load stage coupled to the input stage for generating a first output signal, a first current source coupled to the input stage for allowing a predetermined current to flow, and a second current source, coupled to the input stage, for injecting a first current into the input stage for outputting the first output signal.

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Hsinchu County, Taiwan

Chuan-Ping Tu