The radio-frequency differential circuit includes an input balun, an output balun, a first differential amplifying circuit, a second differential amplifying circuit, a first linear feedback circuit and a second linear feedback circuit; the first differential amplifying circuit is arranged between a first output end of the input balun and a first input end of the output balun; the second differential amplifying circuit is arranged between a second output end of the input balun and a second input end of the output balun; a first end of the first linear feedback circuit is connected with the input balun, a second end of the first linear feedback circuit is connected with the first differential amplifying circuit; a first end of the second linear feedback circuit is connected with the input balun, and a second end of the second linear feedback circuit is connected with the second differential amplifying circuit.

Provided herein are apparatus and methods for a multi-stage signal-processing circuit. The signal-processing circuit can include multiple configurable stages that can be cascaded and configured to process an input signal. Control circuitry can be used to select an output of the configurable stages. Serial data can be recovered with good signal integrity using a signal monitor with the configurable stages by virtually placing the signal monitor on a buffered output node.

A system for testing a subject transistor with constant power. The system may include an amplifier, a measurement voltage source, and a exercise voltage source. The amplifier may have an output connected to a gate of the subject transistor. The amplifier may have a first input and a second input. The measurement voltage source may be connected to the first input of the amplifier for use in measuring characteristics of the subject transistor. The exercise voltage source may be connected to the first input of the amplifier for exercising the subject transistor. The second input of the amplifier may be connected to a source of the subject transistor through a resistor.

A circuital system that includes a differential low-pass filter having a differential output and operable in a first voltage domain. Some embodiments include a differential integrator including a differential input and a differential output, and operable in a second voltage domain different from the first voltage domain. Some embodiments include a pair of AC coupling capacitors coupling the differential output of the differential low-pass filter to the differential input of the differential integrator.

A balanced differential transimpedance amplifier with a single-ended input operational over a wide variation in the dynamic range of input signals. A threshold circuit is employed to either or a combination of (1) generate a varying decision threshold to ensure a proper slicing over a wide range of input current signal levels; and (2) generate a bias current and voltage applied to an input of a transimpedance stage to cancel out a dependence of the transimpedance stage voltage input on input current signal levels.

An operational amplifier comprises: a first amplifier stage 4 comprising a first differential pair of transistors 8, 10 arranged to receive and amplify a differential input signal 18, 20 thereby providing a first differential output signal 22, 24; and a second amplifier stage 6 comprising a second differential pair of transistors 26, 28 arranged to receive and amplify the first differential output signal 22, 24 thereby providing a second differential output signal 38, 40.

An analog-to-digital converter circuit includes: a first operation amplifier suitable for comparing a ramp voltage and a voltage to be converted so as to produce an amplification result and outputting the amplification result; a second operation amplifier suitable for comparing the amplification result transferred to a first input terminal with a reference voltage transferred to a second input terminal so as to produce a comparison result and outputting the comparison result; a leakage current measurer suitable for measuring a leakage current to the first input terminal; and a leakage current generator suitable for causing a current of the same amount as that of the leakage current measured by the leakage current measurer to flow to the second input terminal.

A buffer circuit includes a first differential amplifier, second differential amplifier, third differential amplifier, and mixer. The first differential amplifier generates a positive differential signal and a negative differential signal based on an input signal and a reference voltage signal. The second differential amplifier generates a first signal based on the positive differential signal and the negative differential signal. The third differential amplifier generates a second signal having a different phase from the first signal based on the positive differential signal and the negative differential signal. The mixer outputs a signal, generated by mixing the first signal and the second signal, as an output signal.

A differential input amplification-stage circuit comprises a voltage unit, first and second bulk-driven transistors, first and second mirror current sources, and a differential amplifier unit. The first and the second bulk-driven transistors respectively receive first and second input voltages, and converts the first and the second input voltages into first and second output currents. The differential amplifier unit separately outputs first and second adjustment currents under an action of voltages output by the first to the third voltage output ends. The first and the second mirror current sources respectively output first and second predetermined currents according to the first output current and the first adjustment current, and the second output current and the second adjustment current, so as to maintain transconductance constancy of the differential input amplification-stage circuit. Therefore, output stability is improved.

According to one embodiment, an apparatus comprises a differential signaling bus, a tristate transmitter connected with the differential signaling bus, the tristate transmitter configured to provide a signal on the differential signaling bus responsive to a corresponding control signal, a receiver, a pair of differential inputs of the receiver connected with the differential signaling bus and configured to receive the signal from the differential signaling bus, and a termination circuit configured to couple a first differential input of the pair of differential inputs to a first voltage source and to couple a second differential input of the pair of differential inputs to a second voltage source, wherein the first and second voltage sources have different voltage levels.