A decision feedback equalizer includes a comparator configured to output a constant voltage in a reset period and to output a differential voltage corresponding to differential input signals in an evaluation period, a latch circuit configured to hold the differential voltage in the evaluation period, and an adjuster configured to adjust a logical threshold of the latch circuit closer to the output voltage in the reset period.

Embodiments of the present disclosure relate to a flip flop circuit that obviates the need of a transmission gate. The flip flop includes a first match multiplexer, a second match multiplexer and a separable inverter. The first match multiplexer receives an input data signal and generates a feedback output based on the input data signal and the logic levels at two nodes coupled to the first match multiplexer. The separable inverter receives the feedback output and switches the logic level of one of two nodes but maintains the logic level per each clock cycle. The second match multiplexer generates a signal output based on the logic levels at the two nodes and the signal output that is fed back into the second match multiplexer. Embodiments may reduce power consumption and operate at lower voltages.

A flip-flop circuit includes an evaluation part connected to a first node and a second node to discharge the second node according to a voltage level of the first node, a conditional delay part connected to the second node to discharge a third node to have a voltage level different from a voltage level of the second node, and a keeper logic part connected to the second node and third node to maintain a voltage level of one of the second and third nodes being not discharged.

A flip-flop is provided that includes an input latch, configured to receive a data signal and a complement and produce set and reset pulses based on a clock and a difference between the data signal and the complement; and an output latch, configured to store a data value in a first memory and a complement data value in a second memory based on the set and reset pulses and the clock. Various buffers configured to invert and amplify the set and reset pulses before provision to the output latch stages are optionally disposed between the input and output latches. The input latch includes two signal arms, two difference transistors (one gate controlled by the clock and the other by a clock complement) coupled oppositely to one another (by respective drains and sources) to the signal arms, and two regeneration inverters coupled oppositely to one another to the signal arms.

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 flip-flop is provided that includes an input latch, configured to receive a data signal and a complement and produce set and reset pulses based on a clock and a difference between the data signal and the complement; and an output latch, configured to store a data value in a first memory and a complement data value in a second memory based on the set and reset pulses and the clock. Various buffers configured to invert and amplify the set and reset pulses before provision to the output latch stages are optionally disposed between the input and output latches. The input latch includes two signal arms, two difference transistors (one gate controlled by the clock and the other by a clock complement) coupled oppositely to one another (by respective drains and sources) to the signal arms, and two regeneration inverters coupled oppositely to one another to the signal arms.

A semiconductor integrated circuit includes a sense amplifier circuit suitable for generating differential output signals by sensing and amplifying a level difference of differential input signals in response to a clock signal, and outputting the differential output signals to first and second nodes, respectively, a latch circuit suitable for feeding back and latching the differential output signals between the first and second nodes, and a control circuit suitable for controlling the feedback of the differential output signals between the first and second nodes in response to an initialization signal.

Described is an apparatus to widen or improve a common mode range of a strong arm latch (SAL). In some embodiments, the SAL comprises a master-slave architecture with a common latch. The apparatus includes: a sampler to sample an input with a first clock, and to provide a sampled output on a node. The SAL is to receive the sampled output on the node, and to sample the sampled output according to a second clock. The apparatus comprises a digital-to-analog converter (DAC) coupled to the node, wherein the DAC is to adjust a common mode of the sampled output according to a digital control to the DAC.

Synchronizer circuits having controllable metastability are provided, one of which includes: a first flip-flop circuit comprising a first master latch connected in series with a first slave latch; and a second flip-flop circuit comprising a second master latch connected in series with a second slave latch, wherein an output of the first flip-flop circuit is connected to an input of the second flip-flop circuit, at least a portion of the first flip-flop circuit is implemented in a first PWell isolated by an underlying a deep isolation NWell, at least a portion of the first flip-flop circuit is implemented in a first NWell that electrically contacts the deep isolation NWell, the first NWell is connected to a first bias voltage that is less than a positive power supply voltage, and the first PWell is connected to a second bias voltage that is greater than a negative power supply voltage.

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.