Abstract: A differential bidirectional transceiver is provided. The differential bidirectional transceiver includes a first current transmitter, a second current transmitter and a receiver. The first current transmitter and the second current transmitter are coupled to a first interconnection and a second interconnection, respectively. Each of the current transmitters includes two current sources and two switches. The receiver includes an input circuit consisting of four differential pairs, a current summation circuit and a buffer.

Abstract: A cycle time to digital converter comprises a dual delay lock loop, multi phase sampling detector and VDL sampling detector. The dual delay lock loop generates the first voltage corresponding to the first delay time and the second voltage corresponding to the second delay time. The multi phase sampling detector receives first start signal, first stop signal and first voltage to detect a coarse delay time, generates the first group signals according to the coarse delay time, delays the first stop signal by a common delay time to generate the second stop signal, and delays the first start signal by the coarse delay time and the common delay time to generate the second start signal. The VDL sampling detector receives first voltage, second voltage, second start signal and second stop signal for detecting a fine delay time and generates the second group signals according to the fine delay time.

Abstract: A digitally controlled oscillator (DCO) includes a pulse generator for generating a pulse signal upon an edge of a trigger signal, and at least one delay circuit coupled to delay the pulse signal generated by the pulse generator. The pulse generator is coupled to receive one of the delayed pulse signal from the at least one delay circuit and an enable signal as the trigger signal. A digitally controlled varactor (DCV) includes a transistor having a gate, a source, a drain, and a substrate, wherein at least one of the gate, the source, the drain, and the substrate is coupled to receive one of two or more voltages, wherein at least one of the two or more voltages is not a power supply voltage or ground.

Abstract: A bidirectional current-mode transceiver is provided for improving transmission rates on a transmission line in a manner of current signal transmission, and for reducing the swing of the voltage signal on the transmission line by using a termination resistor, thus improving operating speed. Therefore, the provided transceiver can be applied to a long transmission line.

Abstract: A DLL-based programmable clock generator using a threshold-trigger delay element and an edge combiner is proposed. A threshold-trigger delay element with full swing complementary output signals consumes no dc power. It exhibits small delay error resulting reduced out jitter. It also increases the linearity of delay time versus control voltage. The circular edge combiner can multiply the input signal at a lower supply voltage. The rise and fall time of output signal are more symmetrical. It also present the multiplication factor of the clock generator can be easy to choose with the increasing of the number of delay elements.

Abstract: A pulse-width control loop (PWCL) for clock with any pulse-width ratio within a wide range is provided. A differential programmable charge pump is employed to stabilize the current source by complementary connection. The differential programmable charge pump has a pair of differential charge pumps and a current source module to adjust the ratio of charge to discharge, so as to accelerate the range of the adjustable pulse-width ratio of the output clock and increase the output resolution. Further, a ratioless input control stage is employed to simplify the circuit design and avoid static power consumption. Moreover, the control stage adjusts rising pulse width and dropping pulse width at one period, thereby accelerating the lock speed and the range of the adjustable pulse-width ratio (i.e., duty cycle) of the input clock.

Abstract: A bidirectional current-mode transceiver is provided for improving transmission rates on a transmission line in a manner of current signal transmission, and for reducing the swing of the voltage signal on the transmission line by using a termination resistor, thus improving operating speed. Therefore, the provided transceiver can be applied to a long transmission line.

Abstract: A DLL-based programmable clock generator using a threshold-trigger delay element and an edge combiner is proposed. A threshold-trigger delay element with full swing complementary output signals consumes no dc power. It exhibits small delay error resulting reduced out jitter. It also increases the linearity of delay time versus control voltage. The circular edge combiner can multiply the input signal at a lower supply voltage. The rise and fall time of output signal are more symmetrical. It also present the multiplication factor of the clock generator can be easy to choose with the increasing of the number of delay elements.

Abstract: An N times frequency multiplication circuit uses duty cycle control buffers in combination with edge detectors to provide both multiplication and 50% duty cycle adjustment. Parallel branches of duty cycle control buffers are preset for respective duty cycles of 1/N, 2/N,...,N−1/N. The buffers each receive a common edge detected input signal and simultaneously output their respective duty cycle adjusted clock signals. A rising and falling edge detector generates a pulse train at double the frequency of the 1/N buffer output, while falling edge detectors generate time spaced pulse trains from the outputs of their respective 2/N,...,N−1/N buffers. These pulse trains are combined in an OR gate to provide an output pulse train at a frequency N times the input clock frequency fin. A final stage duty cycle control buffer adjusts the N times fin output signal to a 50% duty cycle.

Abstract: A duty cycle control buffer uses an edge detector input stage to detect the transitions of an unpredictable clock signal input. The edge detector generates one shot output signals in synchronism with the clock signal. A pulse width controllable monostable multivibrator converts the one shot signals into rectangular pulses, at the same frequency as the original clock input. The rectangular pulses are inverted and then averaged, to provide a voltage input to one side of an operational amplifier. A reference voltage is supplied to the other side of the operational amplifier, such that the difference between the average voltage and the reference voltage generates an output control voltage from the operational amplifier. This control voltage provides negative feedback to a pulse width control stage within the monostable multivibrator, thereby adjusting the pulse width of the rectangular pulse output until a steady state is reached.