Techniques efficiently serialize multiple data streams using quadrature clocks. Serializer employs first, second, third, and fourth clock signals. Serializer receives multiple data streams via registers, with each of four paths comprising a register, buffer, and switch, with registers of first and fourth paths associated with third clock signal, and registers of second and third paths associated with first clock signal, and with switches of first and fourth paths associated with first clock signal, and switches of second and third paths associated with third clock signal. Switches of first and second paths transfer respective data bits to fifth switch via another buffer, wherein fifth switch is associated with a delayed second clock signal of a time delay component (TDC). Switches of third and fourth paths transfer respective data bits to sixth switch via another buffer, wherein sixth switch is associated with a delayed fourth clock signal of TDC.

A multiplexer (MUX) calibration system includes main MUX circuitry, first replica MUX circuitry, digital-to-analog (DAC) circuitry, detection circuitry, and control circuitry. The main MUX circuitry receives clock signals and outputs a first data signal based on the clock signals. The first replica MUX circuitry receives the clock signals and outputs a second data signal based on the clock signals. The DAC circuitry generates an offset voltage. The detection circuitry receives the second data signal and the offset voltage and generates a first error signal based on one or more of the second data signal and the offset voltage. The control circuitry receives the first error signal and generates a first control signal indicating an adjustment to the clock signals.

An apparatus for powering an electrical circuit includes a first voltage input configured to receive power from a first voltage source, a second voltage input configured to receive power from a second voltage source, wherein the second voltage source has a lower voltage than the first voltage source, a voltage regulator connected to the first voltage input, and a voltage output configured to switchably receive power from the first voltage input through the voltage regulator or from the second voltage input.

An apparatus for powering an electrical circuit includes a first voltage input configured to receive power from a first voltage source, a second voltage input configured to receive power from a second voltage source, wherein the second voltage source has a lower voltage than the first voltage source, a voltage regulator connected to the first voltage input, and a voltage output configured to switchably receive power from the first voltage input through the voltage regulator or from the second voltage input.

A data input circuit of a semiconductor apparatus may include a plurality of parallelizing units corresponding to a plurality of input/output pads in a one-to-one manner, and a data control block configured to transmit serial test data, which may be input through less than all of the plurality of input/output pads, to the plurality of parallelizing units in response to first and second control signals.

An example pulse generation circuit includes a parallel-to-serial circuit configured to convert parallel data to serial data according to parallel clock signal and a serial clock signal, the serial data comprises a sequence of pulses; a clock generator configured to generate a clock signal; and a phase controller configured to generate the serial clock signal from the clock signal based on a phase control signal.

An example pulse generation circuit includes a parallel-to-serial circuit configured to convert parallel data to serial data according to parallel clock signal and a serial clock signal, the serial data comprises a sequence of pulses; a clock generator configured to generate a clock signal; and a phase controller configured to generate the serial clock signal from the clock signal based on a phase control signal.

A method of protecting a serializer/deserializer (SERDES) differential input/output (I/O) circuit includes detecting an electrostatic discharge event. The method also includes selectively disengaging a power supply terminal from a pair of I/O transistors of the SERDES differential I/O circuit in response to the detected electrostatic discharge event. The method further includes selectively disengaging a ground terminal from the pair of I/O transistors of the SERDES differential I/O circuit in response to the detected electrostatic discharge event.

A method of protecting a serializer/deserializer (SERDES) differential input/output (I/O) circuit includes detecting an electrostatic discharge event. The method also includes selectively disengaging a power supply terminal from a pair of I/O transistors of the SERDES differential I/O circuit in response to the detected electrostatic discharge event. The method further includes selectively disengaging a ground terminal from the pair of I/O transistors of the SERDES differential I/O circuit in response to the detected electrostatic discharge event.

A transmission device of the disclosure includes a first selector configured to select one of a first signal and a second signal, and output the selected signal; a second selector configured to select one of an inversion signal of the first signal, the second signal, and an inversion signal of the second signal, and output the selected signal; a first control signal generator configured to generate a first control signal, a second control signal, and a third control signal, based on the first signal, the second signal, and a third signal; a first driver configured to set a voltage of a first output terminal, based on an output signal of the first selector and the first control signal; and a second driver configured to set a voltage of a second output terminal, based on an output signal of the second selector and the second control signal.