Abstract: An integrated circuit includes a plurality of flip-flops and a global reset network for resetting the flip-flops. The integrated circuit includes a synchronous clock delay circuit that delays, responsive to a global reset signal, a transition in a clock signal provided to the flip-flops. The delay in the transition of the clock signal ensures that all of the flip-flops receive the global reset signal within a same delayed clock cycle and that the flip-flops do not receive the global reset signal during a rising or falling edge of the clock signal.

Abstract: A quantizer generates a thermometer coded signal from an analog voltage signal. Data weighted averaging (DWA) of the thermometer coded signal is accomplished by controlling the operation of a crossbar switch controlled by a switch control signal to generate an output DWA signal. The output DWA signal is latched to generate a latched output DWA signal which is processed along with bits of the thermometer coded input signal in feedback loop to generate the switch control signal. The latching of the output DWA signal is performed in an input register of a digital-to-analog converter which operates to convert the latched output DWA signal to a feedback analog voltage from which the analog voltage signal is generated. The switch control signal specifies a bit location for a beginning logic transition of the output DWA signal cycle based on detection of an ending logic transition of the latched DWA signal.

Abstract: A recursive digital sinusoid generator generates recursive values used in the production of a digital sinusoid output. The recursive values are generated at a first frequency. A sinusoid value generator generates replacement values at a second frequency, wherein the second frequency is less than the first frequency. The generated recursive values are periodically replaced with the generated replacement values without interrupting production of the digital sinusoid output at the first frequency. This periodic replacement effectively corrects for a finite precision error which accumulates in the recursive values over time.

Abstract: A first sampling circuit takes phase offset first samples of a received serial data stream in response to a first edge of a sampling clock and a first comparator circuit determines whether the plurality of phase offset first samples have a same logic state. A second sampling circuit takes phase offset second samples of the received serial data stream in response to a second edge of the sampling clock, opposite the first edge, and a second comparator circuit determines whether the phase offset second samples have a same logic state. One of the first samples or one of the second samples is then selected in response to the determinations made by the first and second comparator circuits. A serial to parallel converter circuit generates an output word including the selected one of the first and second samples.

Abstract: A sigma-delta modulator includes an N-bit quantization circuit that generates a stream of N-bit code words and a feedback signal path with an N-bit DAC circuit, having a non-ideal operation due to mismatch error, that converts the stream of N-bit code words to generate a feedback signal. A digital DAC copy circuit provides a digital replication of the N-bit DAC circuit. The digital replication accounts for the non-ideal operation of the N-bit DAC circuit 126 due to mismatch error, and converts the stream of N-bit code words to generate a stream of P-bit code words, where P>N, that are functionally equivalent to the feedback signal output from the N-bit DAC circuit.

Abstract: Individual bits of a K bit unary data word, wherein K is greater than one, are applied to K polyphase finite impulse response filter circuits. Each polyphase finite impulse response filter circuit receives a different bit and operates with a single bit precision to generate from each received bit a filtered output data word. A gain adjustment is applied by a gain stage circuit to each filtered output data word to generate a corresponding gain adjusted output data word. The gain adjusted output data words from the gain stage circuits are summed to generate an output data word. The unary data word may be output from a source such as a data encoder or a quantizer.

Abstract: A debounce circuit and a method for masking or filtering a glitch from an input signal are provided. The debounce circuit includes a reset synchronizer circuit and a logic circuit. The reset synchronizer circuit receives the input signal, detects a glitch in the input signal and outputs one or more reset synchronizer output signals having a first reset synchronizer state indicating detection of the glitch. The logic circuit receives the one or more reset synchronizer output signals, determines that the one or more reset synchronizer output signals are in the first reset synchronizer state indicating detection of the glitch and in response to determining that the one or more reset synchronizer output signals are in the first reset synchronizer state, keeps an output signal of the debounce circuit in a present state of the output signal of the debounce circuit.

Abstract: A quantizer generates a thermometer coded signal from an analog voltage signal. Data weighted averaging (DWA) of the thermometer coded signal is accomplished by controlling the operation of a crossbar switch controlled by a switch control signal to generate an output DWA signal. The output DWA signal is latched to generate a latched output DWA signal which is processed along with bits of the thermometer coded input signal in feedback loop to generate the switch control signal. The latching of the output DWA signal is performed in an input register of a digital-to-analog converter which operates to convert the latched output DWA signal to a feedback analog voltage from which the analog voltage signal is generated. The switch control signal specifies a bit location for a beginning logic transition of the output DWA signal cycle based on detection of an ending logic transition of the latched DWA signal.

Abstract: A first multiplier multiplies a first input with a first coefficient and a first adder sums an output of the first multiplier and a second input to generate a first output. A second multiplier multiplies a third input with a second coefficient, a third multiplier multiplies a fourth input with a third coefficient, and a second adder sums outputs of the second and third multipliers to generate a second output. The second and third inputs are derived from the first output and the first and fourth inputs are derived from the second output. The first and second outputs generate digital values for first and second digital sinusoids, respectively.

Abstract: A delay line includes a delay chain, a pulse generator generating a pulse based on a received input signal, and a delay chain control circuit. The delay chain control circuit has a first input receiving the pulse, a second input receiving output from a last element of the delay chain, and a selection input receiving a delayed version of the received input signal. The delay chain control circuit has an output coupled to provide input to a first element of the delay chain in response to the delayed version of the received input signal. An output selection circuit receives outputs from each element of the delay chain, counts assertions of the output of the last element of the delay chain and, in response to the count being equal to a desired count, passes a desired one of the outputs of the elements of the delay chain as output.

Abstract: A delay line includes a delay chain, a pulse generator generating a pulse based on a received input signal, and a delay chain control circuit. The delay chain control circuit has a first input receiving the pulse, a second input receiving output from a last element of the delay chain, and a selection input receiving a delayed version of the received input signal. The delay chain control circuit has an output coupled to provide input to a first element of the delay chain in response to the delayed version of the received input signal. An output selection circuit receives outputs from each element of the delay chain, counts assertions of the output of the last element of the delay chain and, in response to the count being equal to a desired count, passes a desired one of the outputs of the elements of the delay chain as output.

Abstract: A sigma-delta modulator includes an N-bit quantization circuit that generates a stream of N-bit code words and a feedback signal path with an N-bit DAC circuit, having a non-ideal operation due to mismatch error, that converts the stream of N-bit code words to generate a feedback signal. A digital DAC copy circuit provides a digital replication of the N-bit DAC circuit. The digital replication accounts for the non-ideal operation of the N-bit DAC circuit 126 due to mismatch error, and converts the stream of N-bit code words to generate a stream of P-bit code words, where P>N, that are functionally equivalent to the feedback signal output from the N-bit DAC circuit.

Abstract: A continuous time Delta-Sigma (CT-??) modulator has an input node configured to receive an input signal and an output node configured to output a digital output signal. The CT-?? modulator includes a feedback loop with a summation circuit configured to sum the digital output signal with a jitter perturbed test signal to generate a signal supplied to an input of a digital to analog converter circuit. A single tone signal is injected with a jitter error of a clock signal to generate the jitter perturbed test signal. A processing circuit processes the digital output signal to detect a signal to noise ratio of the CT-?? modulator. The detected signal to noise ratio is indicative of presence of jitter in the clock signal.

Abstract: A continuous time Delta-Sigma (CT-??) modulator has an input node configured to receive an input signal and an output node configured to output a digital output signal. The CT-?? modulator includes a feedback loop with a summation circuit configured to sum the digital output signal with a jitter perturbed test signal to generate a signal supplied to an input of a digital to analog converter circuit. A single tone signal is injected with a jitter error of a clock signal to generate the jitter perturbed test signal. A processing circuit processes the digital output signal to detect a signal to noise ratio of the CT-?? modulator. The detected signal to noise ratio is indicative of presence of jitter in the clock signal.

Abstract: A recursive digital sinusoid generator generates recursive values used in the production of a digital sinusoid output. The recursive values are generated at a first frequency. A sinusoid value generator generates replacement values at a second frequency, wherein the second frequency is less than the first frequency. The generated recursive values are periodically replaced with the generated replacement values without interrupting production of the digital sinusoid output at the first frequency. This periodic replacement effectively corrects for a finite precision error which accumulates in the recursive values over time.

Abstract: A cascaded integrator-comb (CIC) decimation filter includes N integrator stages, N?1 differentiator stages, and a decimator coupled to receive an integrated signal that is output from the N integrator stage and generate a decimated signal that is input to the N?1 differentiator stages. The decimator periodically asserts an integration reset signal. A last integrator stage of the N integrator stages is reset in response to assertion of the integration reset signal.

Abstract: A digital filtering method includes receiving a digital signal, and passing the digital signal through a Pth order comb cascade. The method includes beginning pre-computing of intermediate integrator states of a Pth order integrator cascade as a function of the digital signal, prior to receiving output from a last comb of the Pth order comb cascade. The outputs from each comb of the Pth order comb cascade are then applied to the pre-computed intermediate integrator states to thereby produce a filtered version of the digital signal. The Pth order comb cascade may operate at a sampling frequency, and the pre-computing of the intermediate integrator states is performed at the sampling frequency, while the application of the outputs from each comb of the Pth order comb cascade to the pre-computed intermediate integrator states is performed at a multiple of the sampling frequency.

Abstract: Data words are received in parallel in response to an edge of a master clock signal and selected for serial output in response to a select signal. For a detected temporal offset of the serially output data words, the generation of the select signal and the master clock signal are controlled to correct for the temporal offset by shifting timing of the edge of the master clock signal and adjusting a sequence of values for the select signal that are generated within one cycle of the master clock signal. For a backward temporal offset, at least one count value in the sequence of values is skipped and the edge of the master clock signal occurs earlier in time. For a forward temporal offset, at least one count value in the sequence of values is held and the edge of the master clock signal occurs later in time.

Abstract: Data words are received in parallel in response to an edge of a master clock signal and selected for serial output in response to a select signal. For a detected temporal offset of the serially output data words, the generation of the select signal and the master clock signal are controlled to correct for the temporal offset by shifting timing of the edge of the master clock signal and adjusting a sequence of values for the select signal that are generated within one cycle of the master clock signal. For a backward temporal offset, at least one count value in the sequence of values is skipped and the edge of the master clock signal occurs earlier in time. For a forward temporal offset, at least one count value in the sequence of values is held and the edge of the master clock signal occurs later in time.

Abstract: A digital filtering method includes receiving a digital signal, and passing the digital signal through a Pth order comb cascade. The method includes beginning pre-computing of intermediate integrator states of a Pth order integrator cascade as a function of the digital signal, prior to receiving output from a last comb of the Pth order comb cascade. The outputs from each comb of the Pth order comb cascade are then applied to the pre-computed intermediate integrator states to thereby produce a filtered version of the digital signal. The Pth order comb cascade may operate at a sampling frequency, and the pre-computing of the intermediate integrator states is performed at the sampling frequency, while the application of the outputs from each comb of the Pth order comb cascade to the pre-computed intermediate integrator states is performed at a multiple of the sampling frequency.