Abstract: An analog-to-digital converter circuit incorporating includes a multi-bit input buffer having a differential input and configured to generate, at a plurality of differential outputs, a plurality of residues of a differential input sample relative to a corresponding plurality of zero-crossing references. Chopping stages chop the residues, for example with a pseudo-random binary sequence. The circuit further includes zero-crossing comparators, each with differential inputs coupled to receive one of the chopped residues. The zero-crossing comparators are in an ordered sequence of zone thresholds within the input range of the circuit. Folding logic circuitry has inputs coupled to outputs of the comparators, and outputs a delay domain signal indicating a magnitude of the one of the residues relative to a nearest zone threshold. Digital stage circuitry generates a digital output word representing the received input sample responsive to the comparator outputs and the delay domain signal.

Abstract: An analog-to-digital converter (ADC) including: a signal input adapted to receive an analog signal; a first reference voltage input adapted to receive a first reference voltage; a second reference voltage input adapted to receive a second reference voltage, the second reference voltage is different than the first reference voltage; a first delay circuit having a first delay input coupled to the signal input, a second delay input coupled to the first reference voltage input, a first delay output and a second delay output; a second delay circuit having a third delay input coupled to the signal input, a fourth delay input coupled to the second reference voltage input; a third delay output and a fourth delay output; a first comparator having a first comparator input coupled to the first delay output, a second comparator input coupled to the second delay output and a first comparator output; and a second comparator having a third comparator input coupled to the third delay output, a fourth comparator input coupled

Abstract: An analog to digital converter (ADC) comprising: a delay circuit having a complementary signal output; a first comparator having an input coupled to the complementary signal output of the delay circuit, the first comparator having a first output and a second output; a first dummy comparator having a first dummy input coupled to the first output and a second dummy input coupled to the second output, the first dummy comparator having a dummy output; a first interpolation comparator having an interpolation output and a first interpolation input coupled to the first output; a second dummy comparator having an input coupled to the interpolation output; and a second interpolation comparator having a second interpolation input and a third interpolation input, the second interpolation input coupled to the interpolation output and the third interpolation input coupled to the dummy output.

Abstract: An analog-to-digital converter (ADC) including: a signal input adapted to receive an analog signal; a first reference voltage input adapted to receive a first reference voltage; a second reference voltage input adapted to receive a second reference voltage, the second reference voltage is different than the first reference voltage; a first delay circuit having a first delay input coupled to the signal input, a second delay input coupled to the first reference voltage input, a first delay output and a second delay output; a second delay circuit having a third delay input coupled to the signal input, a fourth delay input coupled to the second reference voltage input; a third delay output and a fourth delay output; a first comparator having a first comparator input coupled to the first delay output, a second comparator input coupled to the second delay output and a first comparator output; and a second comparator having a third comparator input coupled to the third delay output, a fourth comparator input coupled

Abstract: A method of converting an analog signal to a digital code, comprising: using a first comparator to receive an input signal and a first comparison signal, and to generate a first output as a function of the input signal and the first comparison signal; using a second comparator to receive the input signal and a second comparison signal, and to generate a second output as a function of the input signal and the second comparison signal; and using an interpolation comparator to receive the first and second outputs, and to generate a third output based on relative timing of the first and second outputs; further including multiplexing to permit a second-level comparator to receive timing signals from the interpolation comparator and only one of two dummy comparators.

Abstract: An analog to digital converter (ADC) comprising: a delay circuit having a complementary signal output; a first comparator having an input coupled to the complementary signal output of the delay circuit, the first comparator having a first output and a second output; a first dummy comparator having a first dummy input coupled to the first output and a second dummy input coupled to the second output, the first dummy comparator having a dummy output; a first interpolation comparator having an interpolation output and a first interpolation input coupled to the first output; a second dummy comparator having an input coupled to the interpolation output; and a second interpolation comparator having a second interpolation input and a third interpolation input, the second interpolation input coupled to the interpolation output and the third interpolation input coupled to the dummy output.

Abstract: A comparator includes a pair of back-to-back negative-AND (NAND) gates and a delay circuit coupled to the pair of back-to-back NAND gates. The delay circuit is configured to modulate a triggering clock signal by an input voltage to generate a delayed clock signal with a delay that is based on the input voltage. Each of the pair of back-to-back NAND gates is configured to receive the delayed clock signal and generate a comparator output signal based on the delayed clock signal.

Abstract: A clock-less delay comparator coupled to a first input signal and a second input signal, the clock-less delay comparator comprising: a first transistor having a control terminal coupled to the second input signal, a first current terminal coupled to a first voltage supply, and a second current terminal; a second transistor having a control terminal, a first current terminal coupled to the first voltage supply, and a second current terminal; a third transistor having a control terminal, a first current terminal coupled to the first voltage supply, and a second current terminal; a fourth transistor having a control terminal coupled to the first input signal, a first current terminal coupled to the first voltage supply, and a second current terminal; a fifth transistor having a control terminal coupled to the second input signal, a first current terminal, and a second current terminal coupled to the control terminal of the third transistor; a sixth transistor having a control terminal coupled to the first input

Abstract: A clock-less delay comparator coupled to a first input signal and a second input signal, the clock-less delay comparator comprising: a first transistor having a control terminal coupled to the second input signal, a first current terminal coupled to a first voltage supply, and a second current terminal; a second transistor having a control terminal, a first current terminal coupled to the first voltage supply, and a second current terminal; a third transistor having a control terminal, a first current terminal coupled to the first voltage supply, and a second current terminal; a fourth transistor having a control terminal coupled to the first input signal, a first current terminal coupled to the first voltage supply, and a second current terminal; a fifth transistor having a control terminal coupled to the second input signal, a first current terminal, and a second current terminal coupled to the control terminal of the third transistor; a sixth transistor having a control terminal coupled to the first input

Abstract: An analog-to-digital converter, comprising: a voltage to delay circuit having a voltage input, a threshold voltage input, a first output and a second output, wherein a leading edge of the first output is delayed, by a first delay magnitude, in relationship to a leading edge of the second output; and a first stage including: a first logic gate having a first input coupled to the first output of the voltage to delay circuit, a second input coupled to the second output of the voltage to delay circuit, and an output; and a first stage delay comparator having a first input coupled to the first output of the voltage to delay circuit, a second input coupled to the second output of the voltage to delay circuit, a sign signal output and a first stage delay comparator output, wherein the sign signal output represents whether the voltage input is greater than or less than the threshold voltage input.

Abstract: An analog-to-digital converter, comprising: a voltage to delay circuit having a voltage input, a threshold voltage input, a first output and a second output, wherein a leading edge of the first output is delayed, by a first delay magnitude, in relationship to a leading edge of the second output; and a first stage including: a first logic gate having a first input coupled to the first output of the voltage to delay circuit, a second input coupled to the second output of the voltage to delay circuit, and an output; and a first stage delay comparator having a first input coupled to the first output of the voltage to delay circuit, a second input coupled to the second output of the voltage to delay circuit, a sign signal output and a first stage delay comparator output, wherein the sign signal output represents whether the voltage input is greater than or less than the threshold voltage input.

Abstract: A method of converting an analog signal to a digital code, comprising: using a first comparator to receive an input signal and a first comparison signal, and to generate a first output as a function of the input signal and the first comparison signal; using a second comparator to receive the input signal and a second comparison signal, and to generate a second output as a function of the input signal and the second comparison signal; and using an interpolation comparator to receive the first and second outputs, and to generate a third output based on relative timing of the first and second outputs; further including multiplexing to permit a second-level comparator to receive timing signals from the interpolation comparator and only one of two dummy comparators.

Abstract: An analog-to-digital converter has first and second comparators and an interpolation comparator. The first comparator receives an input signal and a comparison signal, and generates an output as a function of the input signal and the comparison signal. The second comparator receives the input signal and a second comparison signal (different from the first comparison signal), and generates a second output as a function of the input signal and the second comparison signal. The interpolation comparator, operatively connected to the first and second comparators, receives the first and second outputs, and generates a third output based on relative timing of the first and second outputs.

Abstract: An analog-to-digital converter has a logic gate for generating an output signal having a delay corresponding to a delay between input signals. The logic gate includes inputs for receiving the input signals, and an output for outputting the output signal. A delay comparator generates a digital signal representative of the order of the input signals, and generates a delay signal having a delay corresponding to the delay between the input signals. The delay comparator has inputs for receiving the input signals, a digital output for outputting the digital signal, and a delay output for outputting the delay signal. A delay-based analog-to-digital converter, with a front stage and successive residual stages, is also disclosed. A delay comparator having merged comparator, sign-out, and delay-out circuits, and which may be operated within one of successive stages, without a clock, is also disclosed.

Abstract: An analog-to-digital converter has first and second comparators and an interpolation comparator. The first comparator receives an input signal and a comparison signal, and generates an output as a function of the input signal and the comparison signal. The second comparator receives the input signal and a second comparison signal (different from the first comparison signal), and generates a second output as a function of the input signal and the second comparison signal. The interpolation comparator, operatively connected to the first and second comparators, receives the first and second outputs, and generates a third output based on relative timing of the first and second outputs.

Abstract: A system for digitizing a sampled input value includes a digital-to-analog converter for generating an output signal as a function of (1) the sampled input value, (2) a reference value, and (3) digital codes, and a multi-bit analog-to-digital converter for determining the digital codes in first, intermediate, and subsequent cycles. Dither is dynamically added to the digital-to-analog converter in the intermediate cycle. The dither is corrected for in the subsequent cycle.

Abstract: A comparator includes a pair of back-to-back negative-AND (NAND) gates and a delay circuit coupled to the pair of back-to-back NAND gates. The delay circuit is configured to modulate a triggering clock signal by an input voltage to generate a delayed clock signal with a delay that is based on the input voltage. Each of the pair of back-to-back NAND gates is configured to receive the delayed clock signal and generate a comparator output signal based on the delayed clock signal.

Abstract: In described examples, an analog to digital converter (ADC) includes a flash ADC. The flash ADC generates a flash output in response to an input signal, and an error correction block generates a known pattern. A selector block is coupled to the flash ADC and the error correction block, and generates a plurality of selected signals in response to the flash output and the known pattern. A digital to analog converter (DAC) is coupled to the selector block, and generates a coarse analog signal in response to the plurality of selected signals. A residue amplifier is coupled to the DAC, and generates a residual analog signal in response to the coarse analog signal, the input signal and an analog PRBS (pseudo random binary sequence) signal. A residual ADC generates a residual code in response to the residual analog signal.

Abstract: A comparator includes a pair of back-to-back negative-AND (NAND) gates and a delay circuit coupled to the pair of back-to-back NAND gates. The delay circuit is configured to modulate a triggering clock signal by an input voltage to generate a delayed clock signal with a delay that is based on the input voltage. Each of the pair of back-to-back NAND gates is configured to receive the delayed clock signal and generate a comparator output signal based on the delayed clock signal.

Abstract: A comparator includes a first input stage coupled to a first signal input and a first reference input, wherein the first input stage is coupled between a first node and a second node. A second input stage is coupled to a second signal input and a second reference input, wherein the second input stage is coupled between a third node and the second node. An output stage generates at least one output signal in response to the first and second input signals. First switching circuitry is coupled between the first node and the output stage. The first switching circuitry is for coupling the first node to a fourth node in response to a reset signal. Second switching circuitry is coupled between the third node and the output stage. The second switching circuitry is for coupling the third node to a fifth node in response to the reset signal.