An apparatus includes a delta-sigma modulator digital-to-analog converter section having a multiple stag cascaded error cancellation architecture, each stage including a delta-sigma modulator followed by a digital-to-analog converter, the delta-sigma modulator digital-to-analog converter section configured to receive a digital input and to generate an analog output. An inverting amplifier-based analog filter is coupled to receive the analog output, the inverting amplifier-based analog filter configured to filter the analog output to produce a filtered analog output.

A circuit includes a first current source configured to produce a first current in a first current line through a first diode-connected transistor having a voltage drop across the first diode-connected transistor, the first current being proportional to an absolute temperature via a first proportionality factor; a second current source configured to produce a second current in a second current line through a second diode-connected transistor having a voltage drop across the second diode-connected transistor, the second current being proportional to the absolute temperature via a second proportionality factor; a third current source configured to produce a third current in a third current line through a third diode-connected transistor having a voltage drop across the third diode-connected transistor; and a processing network including a sigma-delta analog-to-digital converter, the processing network being coupled to the, the second, and the third diode-connected transistors.

The present invention provides a fractional-N frequency synthesizer comprising a divider controller comprising a multistage noise Shaping (MASH) digital delta-sigma modulator comprising L stages, wherein the Lth stage is configured to receive as an input a high amplitude dither signal.

A delta-sigma modulator (DSM) includes: a first summation circuit coupled to an input signal for subtracting an error feedback signal from the input signal; a tunable signal transfer function coupled to the first summation circuit for setting a desired pole in a frequency response of the DSM; a second summation circuit coupled to the tunable signal transfer function for adding a noise transfer function to an output of the tunable signal transfer function; and a quantizer coupled to the second summation circuit for quantizing an output of the second summation circuit to generate an output of the DSM. The output of the DSM is used as feedback to the first summation circuit as the error feedback signal, and the tunable signal transfer function is dynamically tuned to allow selecting and tuning a center frequency and a bandwidth of the DSM.

An apparatus includes a delta-sigma modulator digital-to-analog converter section having a multiple stag cascaded error cancellation architecture, each stage including a delta-sigma modulator followed by a digital-to-analog converter, the delta-sigma modulator digital-to-analog converter section configured to receive a digital input and to generate an analog output. An inverting amplifier-based analog filter is coupled to receive the analog output, the inverting amplifier-based analog filter configured to filter the analog output to produce a filtered analog output.

In a described example, a circuit includes a digital-to-analog converter (DAC) unit element switch circuit including first and second sign switch inputs, first and second select switch inputs, and first, second and third DAC outputs. Synchronizer logic includes a selection input and first and second synchronization outputs, in which the first synchronization output is coupled to the first select switch input and the second synchronization output is coupled to the second select switch input. Selection logic includes a data input, a sign control output and a selection control output, in which the sign control output is coupled to the first and second sign switch inputs, and the selection control output is coupled to the selection input.

An integrated circuit (IC) chip containing a Delta-Sigma () filter module for a analog-to-digital converter and a method of providing analog to digital conversion are disclosed. The IC chip includes a filter that is connected to receive a digital data stream created by a modulator, provide a multibit data value when a counter reaches a selected number of received bits, and reset the counter responsive to receiving a synchronization pulse. The IC chip also includes a FIFO buffer connected to store the multibit data value only when a synchronization flag is on and to send an interrupt towards a processing unit only after storing a selected number of multibit data values. The IC chip further includes a synchronization module connected to turn on the synchronization flag responsive to receiving the synchronization pulse and to turn off the synchronization flag responsive to the sending of the interrupt.

An integrated circuit (IC) chip containing a Delta-Sigma () filter module for a analog-to-digital converter and a method of providing analog to digital conversion are disclosed. The IC chip includes a filter that is connected to receive a digital data stream created by a modulator, provide a multibit data value when a counter reaches a selected number of received bits, and reset the counter responsive to receiving a synchronization pulse. The IC chip also includes a FIFO buffer connected to store the multibit data value only when a synchronization flag is on and to send an interrupt towards a processing unit only after storing a selected number of multibit data values. The IC chip further includes a synchronization module connected to turn on the synchronization flag responsive to receiving the synchronization pulse and to turn off the synchronization flag responsive to the sending of the interrupt.

Provided is a circuit which can correct an output state in real time and reduce influences of distortion/noise components generated by a delay device. A signal modulation circuit includes a subtractor, an integrator, a phase inverting circuit, a DFF for while inserting a zero level at timing synchronous with the clock signal, delaying and quantizing the signal, a ternary signal generating circuit for generating a ternary signal for selectively driving a load connected to a single power supply into ternary conductive states including a positive current on-state, a negative current on-state, and an off-state, a driver circuit for generating a driving signal for driving a load, and a feedback circuit for feeding back the driving signal from the driver circuit to the input signal.

An analog-to-digital converter circuit usable for measuring a voltage having a large common-mode voltage includes two input voltage nodes, a voltage sensing circuit (that includes a sigma-delta modulator) that senses a voltage between the nodes, a digital filter that outputs a multi-bit digital value, and an input current cancellation circuit. The input current cancellation circuit supplies/draws cancellation currents to/from the nodes to compensate for currents drawn from/supplied to the nodes by the voltage sensing circuit. The input current cancellation circuit includes a digitally-programmable digital processing circuit and a current canceling circuit. In one example, the digital processing circuit includes a sigma-delta modulator that transforms a single-bit digital signal output by the voltage sensing circuit into a single-bit digital signal that drives the current canceling circuit. The transfer function of the current compensation loop is programmable and adjustable by loading digital trim values into the circuit.