Techniques for compensating high-speed digital-to-analog converters (DACs) for static mismatch are described. In ideal circumstances, the current sources of a DAC are identical to each other, leading to a frequency response presenting a relatively flat noise spectrum. In the presence of mismatch, however, the response creates unwanted spurious content, which can negatively affect the DAC's dynamic range. The techniques described herein involve randomized thermometric encoders. First, the direction in which a packet contracts or expands, depending on the value to be encoded, can be randomized. Second, pairs of values in a packet (and/or pairs of values outside the packet) can be swapped with one another in a randomized fashion. Third, the decision of whether to apply randomization or not can itself be randomized. By applying one or more of the randomization techniques described herein, the negative effects of switch timing offset and errors in DC linearity can be mitigated.

Reducing distortions in a digital-to-analog converter is a challenge for circuit designers. For current steering digital-to-analog converters (DACs), a quad switching scheme has been used to remove code-dependent glitching which is otherwise present in dual switching schemes. However, due to various impairments in the circuit, e.g., mismatches in the transistors, some code-dependent distortions remain even when a quad switching scheme is implemented. To address this issue, the quad switching scheme can be randomized to improve dynamic linearity while relaxing driving circuitry design and power constraints. Advantageously, randomization reduces the code dependency of the distortions and makes the distortions appear more noise-like at the output of the DAC.

There is described an analog-to-digital converter, ADC, device (100), comprising: i) a first converter stage (110), comprising a first digital-to-analog converter, DAC, (115), comprising at least two first unit elements (116, 117, 118) each with a first unit element value (U11, U12, U13); ii) a second converter stage (120), comprising a second DAC (125), comprising at least two second unit elements each with a second unit element value (U21, U22, U23); and iii) a control device (180), coupled to the first DAC (115) and the second DAC and configured to: swap at least one of the first unit element values (U1) with at least one of the second unit element values (U2) to obtain corresponding third unit element values (U3) and forth unit element values (U4).

This disclosure relates to a system for mitigating distortion in a signal, including a first calculation circuit configured to determine a bit-cell population available to be activated of a plurality of bit-cells based on a signal strength of an input signal, a second calculation circuit configured to determine a number of bit-cells to be activated based on the signal strength of the input signal, the number of bit-cells to be activated being less than or equal to the bit-cell population, a variable-width dynamic element matching network (variable DEM) configured to activate a first subset of bit-cells of the bit-cell population based on the number of bit-cells to be activated, and one or more fixed-width dynamic element matching networks (fixed DEMs) configured to activate a second subset of bit-cells of the bit-cell population based on the number of bit-cells to be activated.

A circuit 100 is described comprising (i) a first digital-to-analog converter 110, (ii) a second digital-to-analog converter 111, (iii) a plurality of unit elements 120, and (iv) switching circuitry 130. The switching circuitry 130 is adapted so that in a first switching state 231, a set of unit elements 221 of the plurality of unit elements 120 forms part of the first digital-to-analog converter 110, and in a second switching state 232, the set of unit elements 221 forms part of the second digital-to-analog converter 111. Furthermore, a corresponding method of operating a circuit 100 is described.

A multi-step analog-to-digital converter (ADC). The ADC includes a sampling circuitry, a comparator, a trimming circuitry, and a DC offset actuator. The sampling circuitry is configured to sample an input analog signal. The comparator is for comparing the input analog signal sample or a residual component of the input analog signal sample to a reference value in each step. The trimming circuitry is configured to receive at least one low-order bit (e.g., a least significant bit and/or a second-least significant bit) of digital binary bits of each input analog signal sample and average the low order bit over a plurality of input analog signal samples and generate a control signal for correcting an input DC offset of the comparator based on an average value of the low-order bits. The DC offset actuator is configured to correct the input DC offset of the comparator based on the control signal.

A circuit for channel randomization based on time-interleaved ADC includes: a channel selection module for outputting M clock reception control signals and encoded N data reception control signals based on a main clock and a generated random number; a multi-phase clock distribution module for generating N multi-phase clocks according to a sampling main clock, redistributing the multi-phase clocks according to the clock reception control signals, and outputting M redistributed clock signals; a time-interleaved ADC module for outputting M output data and a corresponding number of channel quantization completion signals according to the redistributed clock signals; an adjustable delay module for setting a delay length for the data reception control signals; and a timing distribution control module for controlling, according to delayed data reception control signals and the channel quantization completion signals, the output data to be output sequentially in chronological order.

Computational weight data for an in-memory computation operation is stored in a column of memory cells. The in-memory computation operation is executed by actuating word lines connected to the column of memory cells in response to feature data of the in-memory computation operation. An analog signal generated on a bit line of the column is converted, during a converter computation cycle, a digital signal. That digital signal is processed to generate an output of the in-memory computation operation. A randomization signal is generated and applied to control application of a randomized variation to the converter computation cycle. The processing of the digital signal includes adjusting the digital signal to remove error introduced by the random variation applied to the converter computation cycle. The applied random variation affects the power waveform of the in-memory computation device making it more difficult for a power-based side channel attack to succeed.