Comparators are implemented in many circuits, including analog-to-digital converters (ADCs). Some ADCs demand high bandwidth, low power consumption, and high speed. To address these requirements, a comparator circuit can be implemented without a separate pre-amplifier, where a sampling network drives a latch directly. Specifically, the comparator circuit integrates a pre-amplifier within the latch in a manner that ensures low power and high speed operation.

An Analog to Digital (ADC) is provided, where the ADC may include a sample and hold circuitry to sample an analog input signal, and a summation block to iteratively generate a subtraction signal. The subtraction signal may be based on a difference between the analog input signal and a feedback signal. The ADC may further include a common input stage to receive the subtraction signal, and a plurality of comparison and latch circuitries arranged in parallel, where individual ones of the plurality of parallel comparison and latch circuitries may sequentially receive an output of the common input stage.

Techniques are disclosed relating to level-shifting circuitry and time borrowing across voltage domains. In some embodiments, sense amplifier circuitry generates, based on an input signal at a first voltage level, an output signal at a second, different voltage level. Pulse circuitry may generate a pulse signal in response to an active clock edge of a clock signal that is input to the sense amplifier circuitry. Initial resolution circuitry may drive the output signal of the sense amplifier circuitry to match the value of the input signal during the pulse signal. Secondary resolution circuitry may maintain a current value of the output signal after expiration of the pulse signal. This may allow the input signal to change during the pulse, e.g., to enable time borrowing by upstream circuitry.

A strobe generation circuit includes: a main hybrid multiplexing circuit outputting a main pull-up signal and a main pull-down signal to first and second nodes, respectively, the main pull-up and pull-down signals being selectively controlled based on first pull-up and pull-down control signals generated by removing an input loading of main data; a sub hybrid multiplexing circuit outputting a sub pull-up signal and a sub pull-down signal to the first and second nodes, respectively, the sub pull-up and pull-down signals being selectively controlled based on second pull-up and pull-down control signals generated by removing an input loading of sub data; a latch circuit latching a signal of the first node and a signal of the second node to output a first latch signal and a second latch signal; and an output driver outputting a strobe signal according to the first and second latch signals.

A level shifter includes: an input terminal configured to receive an input signal in a first voltage domain; a first output terminal; a second output terminal; a first inverter configured to receive and shift the input signal to a first output signal at the first output terminal in a second voltage domain higher than the first voltage domain in response to a logical high state of an enable signal in the first voltage domain; a second inverter configured to receive and shift a complement of the input signal to a second output signal at the second output terminal in the second voltage domain in response to the logical high state; a pair of NMOS sensing transistors; a PMOS transistor configured to equalize the first output signal and the second output signal in response to a logical low state of the enable signal.

The invention relates to a high-speed decision device that comprises a first branch and a second branch that are connected in parallel between a power supply end and a clock signal input end; wherein the first branch is used for providing a normal-phase input end, and the second branch is used for providing an inverted-phase input end; a first adjusting point and a second adjusting point are arranged; and an adjusting branch is arranged between the first adjusting point and the second adjusting point, and the adjusting branch is used for adjusting the response speed when the clock signal changes. The benefit of the invention is that the response time of the circuit is further improved, the resolution of the high-speed decision device is improved, and the clock and data recovery performance of the high-speed decision device is further improved.

Comparator circuitry for use in a comparator to capture differences between magnitudes of a pair of comparator input signals in a series of capture operations defined by a reset signal, the circuitry comprising: latch circuitry, comprising a pair of latch input transistors which form corresponding parts of first and second current paths of the latch circuitry respectively, which current paths extend in parallel between high and low voltage sources, a pair of latch output nodes at corresponding positions along the first and second current paths of the latch circuitry respectively, and timing circuitry; and gain-stage circuitry, comprising a pair of cross-coupled gain-stage output transistors connected along respective first and second current paths of the gain-stage circuitry which extend in parallel between high and low voltage sources, and a pair of diode-connected gain-stage output transistors connected in parallel with the pair of cross-coupled gain-stage output transistors, respectively.

A clocked comparator includes a first clocked transconductance amplifier configured to receive a first voltage signal and output a first current signal to an internal node in accordance with a clock; a clocked regenerative load configured to enable a second voltage signal at the internal node to self-regenerate in accordance with the clock; a SR (set-reset) latch configured to receive the second voltage signal at the internal node and output a third voltage signal; and a second clocked transconductance amplifier configured to receive the third voltage signal and output a second current signal to the internal node.

A clocked comparator includes an upper-side sampling latch configured to output a first decision in accordance with a detection of a sign of an input voltage signal plus an offset voltage at an edge of a clock signal; a lower-side sampling latch configured to output a second decision in accordance with a detection of a sign of the input voltage signal minus the offset voltage at the edge of the clock signal; and a decision-arbitrating latch configured to receive the first decision and the second decision and output a final decision in accordance with whichever one of the first decision and the second decision that is resolved earlier.

A level shifter is configured to receive an input signal in a first voltage domain and output an output signal in a second voltage domain. An input terminal is configured to receive an input signal in a first voltage domain. A first sensing circuit is configured to shift the input signal from the first voltage domain to the second voltage domain, and a second sensing circuit is configured to shift the input signal from the first voltage domain to the second voltage domain. An enable circuit is configured to equalize a voltage level of first and second output signals at respective first and second output terminals in response to an enable signal. The first and second sensing circuits are configured output complementary output signals in the second voltage domain at the first and second output terminals in response to the enable signal and the input signal.