A method of Vernier digital-to-analog conversion, the method including: performing conversion of a reference signal Y using a control code X=M+α.sup.−αN with a length ψ=α+β, wherein M is a control code with a length α, including high-order bits of the control code X, and α.sup.−αN is a control code with a length β, including lower-order bits of the control code X, wherein α≈β; performing digital multiplication of the lower-order a.sup.−αN bits of the control code X by a.sup.α times algebraic summing α of the high-order bits of the control code X and β of the lower-order bits of a.sup.−αN of the control code X being a result of multiplication by a.sup.α times, according to formula Q=M±N, wherein Nis a resulting digital code of the digital multiplication, and Q is a resulting digital code of M±N; converting the resulting digital code Q from a reference signal Y.sub.1 to an analog signal Z.sub.1, and converting the resulting digital code N from a reference signal Y.sub.2 to an analog signal Z.sub.2, wherein reference signals Y.sub.1 and Y.sub.2 are related by a ratio: Y.sub.2=Y.sub.1(1±a.sup.−α), wherein a is a base of number system, α is a number of bits of shifting the control code a.sup.−αN; and summing analog signals Z.sub.1 and Z.sub.2 to generate an analog output signal Z.sub.0.

A method for self-calibration of reference voltage drop in a Digital to Analog Converter (DAC) includes measuring each one of a plurality of thermometric weightages associated with a respective one of a plurality of thermometric bits, wherein the DAC includes a plurality of sub-binary bits and the plurality of thermometric bits. For each sequentially increasing combination of thermometric bit settings including at least two thermometric bits coupled to a high reference voltage and each sub-binary bit coupled to a low reference voltage, performing the steps of: determining a respective combined weightage correction; adding the combined weightage correction to the highest order bit of the combination of thermometric bit settings; and incrementing a number of bits of the combination of thermometric bit settings in response to the number of bits of the sequential combination being less than a total number of the plurality of thermometric bits.

A latch circuit sequentially latches a first data weighted averaging (DWA) data word and then a second DWA data word. A first detector circuit identifies a first bit location in the first DWA data that is associated with an ending of a first string of logic 1 bits in the first DWA data word. A second detector circuit identifies a second bit location in the second DWA data word associated with an ending of a second string of logic 1 bits in the second DWA data word. A DWA-to-binary conversion circuit converts the second DWA data word to a binary word by using the first bit location and second bit location to identify a number of logic 1 bits present in said second DWA data word. A binary value for that binary word that is equal to the identified number is output.

An imaging element according to a first aspect includes: a successive approximation resistor type analog-digital converter that converts an analog signal output from a pixel including a photoelectric conversion part into a digital signal, in which the successive approximation resistor type analog-digital converter has a preamplifier having a band limiting function. An imaging element according to a second aspect includes a DAC in which the successive approximation resistor type analog-digital converter uses a capacitance element to convert a digital value after AD conversion to an analog value, and sets the analog value to a comparison reference for comparison with an analog input voltage. Then, the DAC includes one of lower-bit capacitance elements including a plurality of capacitance elements, and after performing AD conversion for all bits, each of the plurality of capacitance elements is selectively applied with at least a first reference voltage to a fourth reference voltage, so that re-AD conversion is performed for lower bits.

A successive approximation ADC includes: a comparator generating a judge signal related to an input analog and a reference signals; a SAR successively generating a register signal including a first and a second bit signals based on the judge signal and generating an AD conversion value of the input analog signal; a thermometer decoder switching different thermometer code conversion rules and converting the first bit signal to thermometer codes corresponding to the different thermometer code conversion rules in one AD conversion cycle; a first and a second DA converters respectively converting the thermometer codes to a first analog signal and the second bit signal to a second analog signal; an average value calculator averaging the AD conversion values by the thermometer codes. Two of the different thermometer codes have values that a high-order bit and a low-order bit groups by dividing total bits of the thermometer code equally are exchanged.

The inventive concept relates to a method and system for cost-effectively predicting the dynamic nonlinearities of on-chip segmented digital-to-analog converter (DAC) and analog-to-digital-converter (ADC), by looping a DAC to an ADC, using a programmable-gain-amplifier (PGA) and an external load board. The method may include a first loopback step of supplying an output signal from a coarse DAC, to which a sinusoidal signal is supplied, to a coarse ADC and a fine ADC through an external load board, a second loopback step of supplying an output signal from a fine DAC, to which a sinusoidal signal is supplied, to the fine ADC and the coarse ADC through the load board, and a step of predicting dynamic nonlinearity of each of a DAC and an ADC by processing equations exhibiting dynamic nonlinearity of a sub-DAC and a sub-ADC, which are obtained in the first loopback step and the second loopback step.

A digital-to-analog converter (DAC) system preferably includes one or more optical modulators and can optionally include one or more electronic DAC arrays. A method for digital-to analog conversion preferably includes receiving digital inputs and providing analog optical outputs. The method for digital-to analog conversion is preferably performed using the DAC system.

Certain aspects of the present disclosure provide a digital-to-analog converter (DAC). The DAC generally includes a plurality of current-steering cells, each having a bypass switch, and a resistor ladder circuit having multiple segments. Each segment may include a first resistive element and a second resistive element, the bypass switch being configured to selectively provide a bypass current to a common node between the first resistive element and the second resistive element.

A latch circuit sequentially latches a first data weighted averaging (DWA) data word and then a second DWA data word. A first detector circuit identifies a first bit location in the first DWA data that is associated with an ending of a first string of logic 1 bits in the first DWA data word. A second detector circuit identifies a second bit location in the second DWA data word associated with an ending of a second string of logic 1 bits in the second DWA data word. A DWA-to-binary conversion circuit converts the second DWA data word to a binary word by using the first bit location and second bit location to identify a number of logic 1 bits present in said second DWA data word. A binary value for that binary word that is equal to the identified number is output.

A solid state imaging element according to an embodiment includes: a converter (14) that converts an analog pixel signal read out from a pixel into a bit value, successively for each of a plurality of bits, on the basis of a threshold voltage set according to a conversion history of the bit converted before a target bit; a plurality of voltage generation units (102a and 102b) that each generate a plurality of reference voltages; and a setting unit (12d) that sets the threshold voltage using the reference voltage selected from the reference voltages generated by each of the voltage generation units on the basis of a conversion result.