Methods and systems are provided for circuits. One method is for increasing device threshold voltage distribution of a plurality of devices of a circuit. The method includes adjusting a device threshold voltage of the plurality of devices by different amounts; and selecting a subset of the plurality of devices with adjusted device threshold voltage by a device selection module for performing a function associated with the circuit. In one aspect, a system for device threshold voltage adjustment is provided. The system includes a sensor module for sensing one or more of temperature and voltage values of a die having a plurality of devices for a circuit; and a threshold temperature and voltage compensation module for receiving an input value from the sensor module to compensate variation in a device threshold voltage caused by changes of one or more of temperature and voltage of the die.

A high-speed and high-precision photonic analog-to-digital conversion device capable of realizing intelligent signal processing. Learning ability of deep learning technology is utilized to learn the nonlinear response and channel mismatch effect of the system and configure optimal parameters of the deep network. Deterioration of photonic analog-to-digital conversion system performance caused by nonlinear distortion and channel mismatch distortion is eliminated in real time, and performance indicators thereof are improved. By using the induction and deduction ability of deep learning technology, intelligent signal processing of the input signal is realized, and users are provided with digital signals that meet the requirements. It's important for improving the performance of microwave photonic systems that require high sampling rate, high time precision, and high sampling accuracy, such as microwave photonic radar and optical communication systems, and also critical to improve the signal processing ability of such systems under complex conditions.

Embodiments of the present disclosure propose analog-to-digital conversion (ADC) systems particularly suitable for Light Detection and Ranging (LIDAR) implementations. An exemplary proposed ADC system is configured to determine whether an absolute value of an analog value is greater than a threshold, and, upon positive determination, assign a predetermined digital value as a digital value corresponding to the analog value, without proceeding with the analog-to-digital conversion of the analog value. Because the ADC system only proceeds with the analog-to-digital conversion, using an ADC, when the input analog value is smaller than the threshold, and otherwise the input analog value is simply assigned some predefined digital value, design complexity and power consumption of the system may be significantly reduced, compared to conventional ADCs used in LIDAR applications.

An analog-to-digital converter including a first stage and a second stage. The first stage includes a first sample-and-hold (SH) having an input coupled to a voltage input node of the ADC, and having a first SH output. The first stage also includes a buffer, a first flash converter and a first digital-to-analog converter (DAC). The buffer has an input coupled to the first SH output and has a buffer output. The first flash converter has an input coupled to the first SH output, and has a first flash converter output. The first DAC has an input coupled to the first flash converter output. The second stage includes a second flash converter having an input coupled to the buffer output.

Amplifiers can be found in pipelined ADCs and pipelined-SAR ADCs as inter-stage amplifiers. The amplifiers can in some cases implement and provide gains in high speed track and hold circuits. The amplifier structures can be open-loop amplifiers, and the amplifier structures can be used in MDACs and samplers of high speed ADCs. The amplifiers can be employed without resetting, and with incomplete settling, to maximize their speed and minimize their power consumption. The amplifiers can be calibrated to improve performance.

A circuit, which is usable in a flash analog-to-digital converter, includes a first switch configured to provide a first reference voltage to a first reference node responsive to a first control signal and a second switch configured to provide the first reference voltage to a second reference node responsive to a second control signal. A third switch is coupled to the first switch and is configured to provide a second reference voltage to the first reference node responsive to a clock signal. Further, a fourth switch is coupled to the second switch and configured to provide the second reference voltage to the second reference node responsive to the clock signal.

A receiver includes: an automatic gain controller (AGC) configured to receive an analog signal; an analog-to-digital converter (ADC) configured to receive an output from the AGC and to output a digitized signal, wherein a most significant bit of the digitized signal corresponds to a sliced data, and a least significant bit of the digitized signal corresponds to an error signal; and an adaptation unit configured to control the AGC, the ADC, or both the AGC and the ADC, based at least in part on the digitized signal to achieve a desired data digitization and data slicing.

A subtractor circuit can be fabricated within an integrated circuit (IC) and can be configured to draw a difference output node to a voltage proportional to a difference between two received N-bit binary numbers. The subtractor circuit includes sets of N inputs that receive N-bit binary numbers, each set of N inputs indexed by an integer bit number n. The subtractor circuit includes two sets of scaled capacitors, each capacitor of one set connected to an n.sup.th input of the corresponding set of N inputs and to the difference output node. Each scaled capacitor has a capacitance equal to 2.sup.(n)*a unit capacitance (C.sub.UNIT). The subtractor circuit includes a reference capacitor connected to ground and the difference output node, and a reset circuit configured to draw, in response to a received RESET signal, the difference output node to ground.

Apparatuses and methods for a multi-level communication architectures are disclosed herein. An example apparatus may include an input/output (I/O) circuit comprising a driver circuit configured to convert a first bitstream directed to a first memory device and a second bitstream directed to a second memory device into a single multilevel signal. The driver circuit is further configured to drive the multilevel signal onto a signal line coupled to the first memory device and to the second memory device using a driver configured to drive more than two voltages.

A circuit, which is usable in a flash analog-to-digital converter, includes a first switch configured to provide a first reference voltage to a first reference node responsive to a first control signal and a second switch configured to provide the first reference voltage to a second reference node responsive to a second control signal. A third switch is coupled to the first switch and is configured to provide a second reference voltage to the first reference node responsive to a clock signal. Further, a fourth switch is coupled to the second switch and configured to provide the second reference voltage to the second reference node responsive to the clock signal.