Background offset calibration of a high-speed analog signal comparator

    公开(公告)号:US11888492B2

    公开(公告)日:2024-01-30

    申请号:US17683650

    申请日:2022-03-01

    IPC分类号: H03M1/06

    CPC分类号: H03M1/0607

    摘要: A background offset calibration system for an analog signal comparator provides low offset without compromising tracking bandwidth. The comparator includes a preamplifier and a decision latch. A switching selectively couples outputs of an analog circuit to the inputs of the preamplifier stage. A state control logic alternatively operates the system in a first phase in which the analog circuit acquires an input signal while the comparator is calibrated, and a second phase in which a comparison is performed by the comparator. In the first phase, the switching circuit disconnects the outputs of the analog circuit from the preamplifier stage and applies a common mode reference to the inputs of the preamplifier. An offset correction circuit determines correction changes from a history of states of the decision latch across multiple sampling cycles. The offset correction circuit adjusts a threshold voltage of the decision latch by applying the correction changes.

    BACKGROUND OFFSET CALIBRATION OF A HIGH-SPEED ANALOG SIGNAL COMPARATOR

    公开(公告)号:US20230283286A1

    公开(公告)日:2023-09-07

    申请号:US17683650

    申请日:2022-03-01

    IPC分类号: H03M1/06

    CPC分类号: H03M1/0607

    摘要: A background offset calibration system for an analog signal comparator provides low offset without compromising tracking bandwidth. The comparator includes a preamplifier and a decision latch. A switching selectively couples outputs of an analog circuit to the inputs of the preamplifier stage. A state control logic alternatively operates the system in a first phase in which the analog circuit acquires an input signal while the comparator is calibrated, and a second phase in which a comparison is performed by the comparator. In the first phase, the switching circuit disconnects the outputs of the analog circuit from the preamplifier stage and applies a common mode reference to the inputs of the preamplifier. An offset correction circuit determines correction changes from a history of states of the decision latch across multiple sampling cycles. The offset correction circuit adjusts a threshold voltage of the decision latch by applying the correction changes.

    Successive approximation register analog-to-digital converter with multiple sample capacitors

    公开(公告)号:US10951225B1

    公开(公告)日:2021-03-16

    申请号:US16821667

    申请日:2020-03-17

    IPC分类号: H03M1/38 H03M1/46 H03M1/12

    摘要: A SAR ADC may include a plurality of capacitor networks, wherein each capacitor network of the plurality of capacitor networks has a sampling capacitor for sampling an analog input signal to the SAR ADC and at least one non-sampling capacitor. The SAR ADC may also include a DAC including a plurality of sub-DACs including at least a first sub-DAC representing most significant bits of an output of the SAR ADC, wherein the output of the first sub-DAC is coupled to the sampling capacitors of the plurality of capacitor networks and a second sub-DAC representing bits of the output of the SAR ADC lesser in magnitude significance than those of the first sub-DAC, wherein the output of the second sub-DAC is coupled to a respective one of at least one non-sampling capacitor of each of the plurality of capacitor networks.