A switched capacitor digital power amplifier (DPA) or a digital-to-analog converter (DAC) is disclosed. The DPA/DAC includes a plurality of switched capacitor cells connected in parallel. Each switched capacitor cell includes a capacitor and a switch. The switch selectively drives the capacitor in response to an input digital codeword. The switched capacitor cells are divided into sub-arrays and a series capacitor is inserted in series between two adjacent sub-arrays of switched capacitor cells. All the sub-arrays of switched capacitor cells may be in a unary-coded structure. Alternatively, at least one of the sub-arrays may be in a C-2C structure and at least one another sub-array may be in a unary-coded structure. The switch in the switched capacitor cells is driven by a local oscillator signal, and a phase correction buffer may be added for adjusting a delay of the local oscillator signal supplied to sub-arrays of switched capacitor cells.

A digital-to-analog converter is provided. The digital-to-analog converter includes a plurality of digital-to-analog converter cells coupled to an output node of the digital-to-analog converter. At least one of the plurality of digital-to-analog converter cells includes a capacitive element configured to generate an analog cell output signal based on a drive signal. The at least one of the plurality of digital-to-analog converter cells further includes a driver circuit configured to generate the drive signal, and a resistive element exhibiting a resistance of at least 20. The resistive element is coupled between the driver circuit and the capacitive element or between the capacitive element and the output node.

Comparators are implemented in many circuits, including analog-to-digital converters (ADCs). Some ADCs demand high bandwidth, low power consumption, and high speed. To address these requirements, a comparator circuit can be implemented without a separate pre-amplifier, where a sampling network drives a latch directly. Specifically, the comparator circuit integrates a pre-amplifier within the latch in a manner that ensures low power and high speed operation.

Comparators are implemented in many circuits, including analog-to-digital converters (ADCs). Some ADCs demand high bandwidth, low power consumption, and high speed. To address these requirements, a comparator circuit can be implemented without a separate pre-amplifier, where a sampling network drives a latch directly. Specifically, the comparator circuit integrates a pre-amplifier within the latch in a manner that ensures low power and high speed operation.

This disclosure describes systems, methods, and apparatus for a digital-to-analog (DAC) converter, that can be part of a variable capacitor and/or a match network. The DAC can include a digital input, an analog output, N contributors (e.g., switched capacitors), and an interconnect topology connecting the N contributors, generating a sum of their contributions (e.g., sum of capacitances), and providing the sum to the analog output. The N contributors can form a sub-binary sequence when their contributions to the sum are ordered by average contribution. Also, the gap size between a maximum contribution of one contributor, and a minimum contribution of a subsequent contributor, is less than D, where D is less than or equal to two time a maximum contribution of the first or smallest of the N contributors.

SAR-DAC devices and operation methods of SAR-DAC devices are provided. An exemplary SAR-DAC device includes a comparator having a positive input terminal and a negative input terminal; and a DAC core unit including a first capacitor, a second capacitor, and a current-controlled discharging structure. The first capacitor includes a first charging-discharging terminal. The second capacitor includes a second charging-discharging terminal. The current-controlled discharging structure includes current beam circuit units. Each current beam circuit unit includes a first discharging input terminal connected to the first charging-discharging terminal and a second discharging input terminal connected to the second charging-discharging terminal. The current-controlled discharging structure is configured to discharge the first capacitor through the first discharging input terminal by using at least some of the current beam circuit units; and to discharge the second capacitor through the second discharging input terminal using at least some of the current beam circuit units.

This invention discloses a control circuit and a control method of a successive approximation register analog-to-digital converter (SAR ADC). The SAR ADC includes a comparator and a switched-capacitor digital-to-analog converter (DAC). The control circuit includes a memory, an inverter and a data path. The memory is configured to store an output value of the comparator. The inverter has an output coupled to a first end of a capacitor of the switched-capacitor DAC. A second end of the capacitor is coupled to an input of the comparator. The data path, coupled between an output of the comparator and an input of the inverter, temporarily causes a voltage at the first end of the capacitor to be controlled by the output value of the comparator. The data path does not contain any memory.

A memory array structure that includes memory columns having first bit lines and second bit lines is introduced. Each of the memory columns includes a bit line pair, a pre-charge switch pair and a first switch pair. Output voltages from the first bit lines and the second bit lines are used to generated a first average voltage and a second average voltage, respectively. One of the first average voltage and the second average voltage is a lower average voltage and another one of the first average voltage and the second average voltage is a higher average voltage. The pre-charge switch pair and the first switch pair of a selected memory column among the plurality of memory columns are controlled to repeatedly perform an incremental step to increment the lower average voltage by a step voltage until the lower average voltage is greater than the higher average voltage.

A multi-level capacitive digital-to-analog converter, comprises at least one capacitor switch circuit (100) including a differential operational amplifier (130) having a first input node (E130a) and a second input node (E130b). A first current path (101) is coupled to a first reference input terminal (E100a) to apply a first reference potential (RefP) and the second current path (102) is coupled to a second reference input terminal (E100b) to apply a second reference potential (RefN). The at least one capacitor switch circuit (100) comprises a first controllable switch (111) being arranged between the second input node (E130a) of the differential operational amplifier (130) and the first current path (101). The at least one capacitor switch circuit (100) comprises a second controllable switch (112) being arranged between the first input node (E130a) of the differential operational amplifier (130) and the second current path (102).

A stage, suitable for use in an analog to digital converter or a digital to analog converter where the stage comprises a plurality of slices that can be operated together to form a composite output, can have reduced thermal noise, whilst each slice on its own has sufficiently small capacitance to respond quickly to changes in digital codes applied to the slice. This allows a fast conversion to be achieved without loss of noise performance.