A circuit (100) comprises an input terminal (141) which is configured to receive an analog input signal (142). The circuit (100) also comprises a combination element (601) which is configured to combine a number of time-displaced signal values of the input signal (142) to form an analog combination signal (144). The circuit (100) also comprises a quantizer (131) having a converter core which is configured to receive the combination signal (144) via passive charge redistribution from the combination element (601) and to convert it into a digital output signal (145). Such techniques can thus provide for an analog/digital conversion with filtering in the analog domain.

Circuits and methods for inter-symbol interference compensation are described. These circuits and methods may be used in connection with delta-sigma analog-to-digital converter. During a sensing phase, a value indicative of the inter-symbol interference may be sensed. The value may be obtained by (1) causing the ADC to generate a first number of transitions during a first time interval; (2) causing the ADC to generate a second number of transitions during a second time interval; (3) sensing the number of logic-0s and logic-1s occurring in the first and second time intervals; and (4) computing the value based at least in part on the number of logic-0s and logic-1s occurring in the first and second time intervals. During a compensation phase, inter-symbol interference may be compensated based on the value obtained in the sensing phase.

A continuous-time delta-sigma modulator, CTDSM (400, 500, 700, 800) is described that comprises: an operational transconductance amplifier, OTA, (406, 506, 706, 806) having an input port (404, 504, 719, 739, 819, 839) configured to receive an analog input signal and an output port (408, 508, 707, 708, 807, 808); an input low pass filter network comprising at least one input resistor, R1, (402, 502, 702, 722, 802, 822) at least one first shunt capacitor, C1, (403, 503, 703, 803) and at least one feedback resistor, Rdac (410, 510, 710, 810, 730, 830) connected to the input port of the OTA; an output filter network comprising a shunt second resistor, R2, (415, 515, 715, 815) in parallel to a second shunt capacitor, C2, (414, 514, 714, 814), and coupled to the output port (408, 508, 707, 708, 807, 808) of the OTA; a quantizer (413, 513, 713, 813) connected to the output filter network and having at least one output connected to the input port of the OTA via the at least one feedback resistor, Rdac; and wherein the input and output port of the OTA connected by a third feedforward-feedback capacitor, C3, (409, 509, 709, 729, 809, 829) arranged to provide a positive feedback around the OTA.

An integrated circuit includes (a) an analog-to-digital converter operated according to a first clock signal; and (b) a charge pump circuit providing a negative power supply voltage to the integrated circuit, the charge pump circuit being operated according to a second clock signal having a frequency that is different from a frequency of the first clock signal, such that a noise level introduced by the charge pump into the analog-to-digital converter is less than the average noise level over a predetermined range of frequencies for the second clock signal. The integrated circuit may further include a clock divider circuit (e.g., a programmable clock divider) that generates both the first clock signal and the second clock signal.

An analog-to-digital converter (ADC) includes an input terminal configured to receive an analog input signal. A first ADC circuit is coupled to the input terminal and includes a VCO. The first ADC circuit is configured to output a first digital signal in a frequency domain based on the analog input signal. The first digital signal includes an error component. A first DAC is configured to convert the first digital signal to an analog output signal. A first summation circuit is configured to receive the analog output signal, the analog input signal, and a loop filtered version of the analog input signal and extract the error component, and output a negative of the error component. A second ADC circuit is configured to convert the negative of the error component to a digital error signal. A second summation circuit is configured to receive the first digital signal and the digital error signal, and to output a digital output signal corresponding to the analog input at an output terminal.

An analog-to-digital converter (ADC) includes an input terminal configured to receive an analog input signal. A first ADC circuit is coupled to the input terminal and includes a VCO. The first ADC circuit is configured to output a first digital signal in a frequency domain based on the analog input signal. The first digital signal includes an error component. A first DAC is configured to convert the first digital signal to an analog output signal. A first summation circuit is configured to receive the analog output signal, the analog input signal, and a loop filtered version of the analog input signal and extract the error component, and output a negative of the error component. A second ADC circuit is configured to convert the negative of the error component to a digital error signal. A second summation circuit is configured to receive the first digital signal and the digital error signal, and to output a digital output signal corresponding to the analog input at an output terminal.

A circuit includes a first amplifying stage, a noise extraction circuit and a noise cancellation circuit. The first amplifying stage is arranged for receiving an input signal to generate an amplified input signal. The noise extraction circuit is coupled to the first amplifying stage, and is arranged for receiving at least the amplified input signal to generate a noise signal associated with noise components of the amplified input signal. The noise cancellation circuit is coupled to the first amplifying stage and the noise extraction circuit, and is arranged for cancelling noise components of the amplified input signal by using the noise signal generated by the noise extraction circuit, to generate a noise-cancelled amplified input signal.

A circuit (100) comprises an input terminal (141) which is configured to receive an analog input signal (142). The circuit (100) also comprises a combination element (601) which is configured to combine a number of time-displaced signal values of the input signal (142) to form an analog combination signal (144). The circuit (100) also comprises a quantizer (131) having a converter core which is configured to receive the combination signal (144) via passive charge redistribution from the combination element (601) and to convert it into a digital output signal (145). Such techniques can thus provide for an analog/digital conversion with filtering in the analog domain.

A circuit includes a first amplifying stage, a noise extraction circuit and a noise cancellation circuit. The first amplifying stage is arranged for receiving an input signal to generate an amplified input signal. The noise extraction circuit is coupled to the first amplifying stage, and is arranged for receiving at least the amplified input signal to generate a noise signal associated with noise components of the amplified input signal. The noise cancellation circuit is coupled to the first amplifying stage and the noise extraction circuit, and is arranged for cancelling noise components of the amplified input signal by using the noise signal generated by the noise extraction circuit, to generate a noise-cancelled amplified input signal.

The described techniques address issues associated with hybrid current or magnetic field sensors used to detect both low- and high-frequency magnetic field components. The hybrid sensor implements a DC component rejection path in the high-frequency magnetic field component path. Both digital and analog implementations are provided, each functioning to generate a DC component cancellation signal to at least partially cancel a DC component of a current signal generated via the high-frequency magnetic field component path. The hybrid sensor provides a high-bandwidth, high-accuracy, and low DC offset hybrid current solution that also eliminates the need for DC decoupling capacitors in the high-frequency path. A modification is also described for implementing a Sigma-Delta () quantization noise reduction path to reduce the quantization noise and to improve accuracy.