This disclosure describes techniques for performing computational operations on input unary bit streams using one or more scaling networks. In some examples, a device is configured to perform a digital computational operation, where the device includes a plurality of input wires and a plurality of output wires. Each input wire is configured to receive a respective input bit of an encoded input value, and each output wire is configured to output a respective output bit of an encoded output value. The device also includes scaling network circuitry configured to apply a function to the encoded input value by electrically routing at least one input wire of the plurality of input wires to at least two output wires of the plurality of output wires. The device can also include hybrid binary/unary computations.

A system includes an input shuffling circuit and digital-to-analog conversion circuitry. The input shuffling circuit includes a data input, a data output, and a control input. The input shuffling circuit is operable to receive, via the data input, an N-bit binary value, where N is an integer. The input shuffling circuit is operable to route each of the N bits of the N-bit binary word to one or more of M bits of the data output to generate an M-bit value, where M=2N, and the routing is based on a control value applied to the control input. The input shuffling circuit can be configured either in a dynamic element matching (DEM) mode or a regular binary to thermometer mode. The digital-to-analog conversion circuitry is operable to convert the M-bit value to a corresponding analog voltage and/or current. M different values of the control value may result in M different routings of the N bits of the binary word.

The n-bit decoder circuit includes 2.sup.n base circuits each outputting, as the output signal OA, 0, 1 or the input signal IA depending on setting of selection signals S<1:0>; and the (n1)-bit decoder circuit. The (n1)-bit decoder circuit includes 2.sup.(n-1) base circuits and an (n2)-bit decoder circuit in cases of n3, and includes the 1-bit decoder circuit in cases of n=2. The 1-bit decoder circuit outputs 00 in cases of the binary input BIN<0>=0 and outputs 01 in cases of the binary input BIN<0>=1 as thermometer outputs THM(1)<1:0>.

A family of current mode analog to digital converters, or TiADC, utilizing methods, circuits, and apparatuses, are disclosed with the following benefits: (1) There are normal and random non-systematic mismatch between devices in silicon manufacturing, that introduce non-linearity in current mode analog to digital converter's, or iADC, reference network. The iADC's linearity is improved by utilizing a thermometer current mode signal conditioning method, SCM. Successive applications of the SCM effectuates a segmented current reference network to function like a thermometer network, which operates based on the function of summation. Having a TiADC with a thermometer reference network, where current segments are summed or accumulated incrementally, would inherently reduce the impact of statistical distribution of component's random mismatch on the iADC's non-linearity. Accordingly, linearity of TiADC can be improved by the square root of the sum of the square of mismatch errors of the number of segmented current references in the thermometer network. (2) speed is improved by operating the TiADC in current mode, which is inherently faster. (3) voltage swings in current mode are small, which enables the iADC to operate at lower power supply voltages. (4) The TiADC can operate in subthreshold and at very low currents, which lower powers consumption. (5) the TiADC is asynchronous. Being clock free, TiADC has lower dynamic power consumption with reduces digital system noise. (6) the signal conditioning method or SCM utilized in TiADC provides concurrent functions of analog differencing and digital comparison. This trait enhances the dynamic response of iADC, wherein the digital output throughput accuracy degrades gradually and not abruptly as a function of increasing frequency of iADC's input signal. (7) No passive devices, such as capacitors or resistors, are required for the TiADC. (8) TiADC can be fabricated on low cost mainstream standard digital CMOS processes.

The n-bit decoder circuit includes 2.sup.n base circuits each outputting, as the output signal OA, 0, 1 or the input signal IA depending on setting of selection signals S<1:0>; and the (n-1)-bit decoder circuit. The (n-1)-bit decoder circuit includes 2.sup.(n-1) base circuits and an (n-2)-bit decoder circuit in cases of n 3, and includes the 1-bit decoder circuit in cases of n=2. The 1-bit decoder circuit outputs 00 in cases of the binary input BIN<0>=0 and outputs 01 in cases of the binary input BIN<0>=1 as thermometer outputs THM(1)<1:0>.

An apparatus may include a delta sigma modulator. A first portion of the delta sigma modulator may form a digital predictor while a second portion of the delta sigma modulator may form an analog approximator. An output of the analog approximator may be coupled with a quantizer. The digital predictor, the analog approximator, and the quantizer may form a digitizing loop configured to convert an analog input into a digital output. The digital predictor may be configured to generate, based on a polarity of one or more digital outputs from the quantizer, a digital prediction of an expected amplitude of the analog input. The quantizer may be configured to respond to the digital prediction by adjusting a dynamic range of the digitizing loop including by changing a quantization step size used by the quantizer to quantize the analog input. Related methods are also provided.

An analog-to-digital converter (ADC) includes a digital-to-analog converter (DAC) that has a configurable capacitor array. Based on measurements of differential nonlinearity (DNL) and/or integral nonlinearity (INL) error by an external test computer system, an order for use of the DAC's capacitors can be determined so as to reduce DNL error aggregation, also called INL. The DAC includes a switch matrix that can be programmed by programming data supplied by the test computer system.

A phase rotator receives control signals and thermometer coded signals that specifies the phase of an output signal. The phase rotator may be used, for example, by a clock and data recovery (CDR) circuit to continually rotate the phase of a clock to compensate for phase/frequency mismatches between received data and the clock. The control signals determine the phase quadrant (i.e., 0-90, 90-180, etc.) of the output signal. The thermometer coded signals determine the phase of the output signal within a quadrant by steering a set of bias currents between two or more nodes. The set of bias currents are selected to reduce the non-linearity between the thermometer coded value and the phase of the output signal.

A method of duty cycle adjustment includes conditionally inverting an input clock into a conditionally inverted clock; and adjusting a duty cycle of the conditionally inverted clock in one direction in accordance with an integer that represents an amount of duty cycle adjustment, using an uneven clock buffer and a plurality of uneven clock multiplexers that are cascaded and incrementally activated as a value of the integer increments.

A digital to analog converter (DAC) that receives a binary coded signal and generates an analog output signal includes a binary-to-thermometer decoder and a resistive network. The decoder receives the binary coded signal, and decodes it into thermometer signals. The resistive network has branches that are coupled to an output terminal of the DAC in response to the thermometer signals. Each of the branches includes first and second resistors, and a switch. The first resistor is coupled between a first reference voltage and the switch, and the second resistor is coupled between a second reference voltage and the switch. The switch couples either the first resistor or the second resistor to the output terminal in response to a corresponding thermometer signal.