Abstract: An apparatus is provided. The apparatus comprises a sample switch, a sampling capacitor, an amplifier, feedback branches, a second hold switch, an N-bit converter pair, a third hold switch, and an M-bit converter pair. The sample receives an input signal and is actuated by a sample signal. The sampling capacitor is coupled to the sample switch. The amplifier has a first input terminal that is coupled to the sampling capacitor. The feedback branches are coupled between the output terminal of the amplifier and the first input terminal of the amplifier, with each feedback branch including a feedback capacitor, and a first hold switch that is coupled to the feedback capacitor. The second hold switch is coupled to the sampling switch. The N-bit converter pair is coupled to the sampling switch and to the second hold switch. The third hold switch is coupled to at least one of the feedback branches, and the M-bit converter pair is coupled to the output terminal of the amplifier and to the third hold switch.

Abstract: Multiplying digital-to-analog converters (MDACs), which are generally employed in pipelined analog-to-digital converters (ADCs), can have a settling error associated with the MDAC amplifier. Here, a circuit is provided that includes additional amplifiers and a capacitor network that compensates for this settling error. Thus, a more accurate pipelined ADC can now be produced.

Abstract: Delay locked loops or DLLs are oftentimes employed in pipelined analog-to-digital converters (ADCs). Conventional DLLs, though, can consume an excessive amount of power. Here, a DLL is provided with a modified charge pump that allows for reduced power consumption.

Abstract: A time-interleaved analog-to-digital converter (ADC) is provided. The ADC generally comprises a first ADC, a second ADC, correction circuit, a divider, and a clocking circuit. The first ADC receives an analog input signal and generates a first output and a differentiated output. The second ADC receives the analog input signal and generates a second output. The correction circuit receives the first output, the second output, and the differentiated output and generates a first error signal and a second error signal. The divider receives the first error signal and the second error signal and generates a timing error by dividing the second error signal by the first error signal, and the clocking circuit receives a clock signal and the timing error and generates a plurality of corrected clocking signals, where each of the first and second ADCs receives at least one of the clocking signals.

Abstract: An apparatus is provided. The apparatus comprises a sample switch, a sampling capacitor, an amplifier, feedback branches, a second hold switch, an N-bit converter pair, a third hold switch, and an M-bit converter pair. The sample receives an input signal and is actuated by a sample signal. The sampling capacitor is coupled to the sample switch. The amplifier has a first input terminal that is coupled to the sampling capacitor. The feedback branches are coupled between the output terminal of the amplifier and the first input terminal of the amplifier, with each feedback branch including a feedback capacitor, and a first hold switch that is coupled to the feedback capacitor. The second hold switch is coupled to the sampling switch. The N-bit converter pair is coupled to the sampling switch and to the second hold switch. The third hold switch is coupled to at least one of the feedback branches, and the M-bit converter pair is coupled to the output terminal of the amplifier and to the third hold switch.

Abstract: A time-interleaved (TI) analog-to-digital converter (ADC) is provided. The TI ADC generally comprises a clock generator, two or more ADCs, adjustable delay elements, and an estimator. The clock generator generates clock signals. Each ADC is associated with at least one of the clock signals so as to sample an input signal that is generally wide-sense stationary at sampling instants, where correlation function exist between samples from a two or more of the ADCs that is a function of the time differences between associated sampling instants. The estimator is coupled to each of the adjustable delay elements and each of the ADCs so as to calculate the correlation function and adjust the adjustable delay elements to account for sampling mismatch between the ADCs based at least in part on the correlation function.

Abstract: A time-interleaved analog-to-digital converter (ADC) is provided. The ADC generally comprises a first ADC, a second ADC, correction circuit, a divider, and a clocking circuit. The first ADC receives an analog input signal and generates a first output and a differentiated output. The second ADC receives the analog input signal and generates a second output. The correction circuit receives the first output, the second output, and the differentiated output and generates a first error signal and a second error signal. The divider receives the first error signal and the second error signal and generates a timing error by dividing the second error signal by the first error signal, and the clocking circuit receives a clock signal and the timing error and generates a plurality of corrected clocking signals, where each of the first and second ADCs receives at least one of the clocking signals.

Abstract: Parallel search circuit for a medical implant receiver. The circuit includes a radio frequency receiver that receives a first set of contents of a band of channels. The circuit also includes a processing circuit coupled to the radio frequency receiver to process in parallel a second set of contents of a plurality of channels of the band of channels and to detect a signal in the band of channels.

Abstract: An offset correction circuit examines a residue signal of a stage of a pipeline analog to digital converter (ADC) to determine whether a parameter which could cause offset error, needs to be adjusted. In an embodiment, the parameter is adjusted until a maximum range of the residue signal equals an expected range. In the described examples, the adjusted parameters include timing offset error (when components of an ADC sample the input signal at different time instances) and a voltage offset error (the threshold voltage at which a sub-ADC in a stage the generated sub-code changes to a next value).

Abstract: An offset correction circuit examines a residue signal of a stage of a pipeline analog to digital converter (ADC) to determine whether a parameter which could cause offset error, needs to be adjusted. In an embodiment, the parameter is adjusted until a maximum range of the residue signal equals an expected range. In the described examples, the adjusted parameters include timing offset error (when components of an ADC sample the input signal at different time instances) and a voltage offset error (the threshold voltage at which a sub-ADC in a stage the generated sub-code changes to a next value).

Abstract: Removing an Nth harmonic (of a fundamental frequency) generated due to non-ideal ADC operation from the output of the ADC. In an embodiment, digital values containing in-phase and quadrature phase components of the Nth harmonic are generated using mathematical operations, scaled using scaling factors, and then subtracted from the (non-ideal) output of the ADC. A continuous-time derivative of the input signal used to generate the quadrature phase component, enabling a same set of scaling factors to be used for the same input irrespective of the sampling frequency. Spurious Free Dynamic Range of the ADC is thus improved.

Abstract: A delay locked loop (DLL) circuit in which situations of lock to multiple periods of a reference signal is determined by a lock detector using dummy delay elements and a duty cycle correction circuit (DCC). The lock detector, the dummy delay elements and the delay control circuit are used in a path parallel to the delay elements which generate the desired delayed signals having different delays in relation to the reference signal. Due to the use of the parallel path, the throughput performance of the DLL circuit is not impeded. In an embodiment, separate charge pumps are used by a phase comparator and the lock detector used in the parallel path.

Abstract: According to an aspect of the present invention, samples of an input signal are provided with reduced distortion, when the input signal is received from a lead terminal offering lead inductance on an input path. Such a feature is achieved by charging a energy storage element to a value proportional to the input signal using a portion of charging energy received through a path having less lead inductance compared to the path connecting the input signal to the energy storage element. Thus, the energy drawn through the lead impedance is reduced, thereby reducing the magnitude of the distortion caused.

Abstract: Equal common mode voltage is present at the input terminals of an operational amplifier with amplifies the residue signal in a stage of an ADC in two phases while reducing the noise introduced into the amplified signal. A reference capacitor is coupled between an input terminal of the operational amplifier and a reference voltage in a first phase, and between the input terminal and a the reference voltage but with opposite polarity in the second phase.

Abstract: A stage of a pipeline ADC which uses separate pairs of sampling network and amplifier (in a sample and hold circuit (SHA)) to provide inputs to quantizer (which generates a sub-code) and a switched capacitor network (implementing a DAC, a subtractor and amplification). Due to the use of separate components/paths to provide the input signal, the throughput performance of the ADC is enhanced.

Abstract: A clamping circuit containing a transistor and a current amplifier. The transistor is designed to turn on when the voltage at a node exceeds (falls below) a specified upper (lower) level. The current amplifier is designed to draw substantial amount of current when the transistor is turned on to clamp the voltage at the node to the desired level.

Abstract: An integrated circuit provides digital output signals in either single-ended or differential form on a shared set of pins. A control circuit generates signals to ensure that when one form (single-ended or differential) of outputs are being provided, outputs in the other form are disabled. Outputs in differential form may be provided at twice the frequency as compared to the outputs in single-ended form. As a result the same number of pins can be supported for both single-ended and differential outputs for a desired data throughput, and the pin count of the integrated circuit is reduced.

Abstract: According to an aspect of the present invention, samples of an input signal are provided with reduced distortion, when the input signal is received from a lead terminal offering lead inductance on an input path. Such a feature is achieved by charging a energy storage element to a value proportional to the input signal using a portion of charging energy received through a path having less lead inductance compared to the path connecting the input signal to the energy storage element. Thus, the energy drawn through the lead impedance is reduced, thereby reducing the magnitude of the distortion caused.

Abstract: Providing a substantially constant reference voltage to a component from a reference buffer connected by a path. The load that would be offered to the reference buffer in desired durations is estimated, and a dummy load is added to the path such that the aggregate load on the path is approximately constant. In case of the stages of an ADC, the sub-code generated by each stage during a sampling phase is used to estimate the load that would be offered, and the dummy load is added in the hold phase to keep the reference voltage constant in the hold phase, as desired.

Abstract: A delay locked loop (DLL) circuit in which situations of lock to multiple periods of a reference signal is determined by a lock detector using dummy delay elements and a duty cycle correction circuit (DCC). The lock detector, the dummy delay elements and the delay control circuit are used in a path parallel to the delay elements which generate the desired delayed signals having different delays in relation to the reference signal. Due to the use of the parallel path, the throughput performance of the DLL circuit is not impeded. In an embodiment, separate charge pumps are used by a phase comparator and the lock detector used in the parallel path.