Abstract: Disclosed are an offset calibration method and circuit applied to a comparator array. The offset calibration circuit includes a global calibration voltage generation module, integrators, comparators, a global logic control circuit, and local logic control circuits; an entire comparator array shares the single global calibration voltage generation module, and each of the comparators only needs to introduce an integrator circuit, such that a large calibration range and a small calibration step are achieved, a long calibration cycle and a large circuit area are required, and the requirements for a low area are satisfied. The offset calibration method provided by the present disclosure is similar to a binary search algorithm, which is adopted to search for the offset voltage, the calibration step of 1 2 N ? Vref can be realized by only N cycles, and short calibration time is thus realized.

Abstract: Disclosed are an offset calibration method and circuit applied to a comparator array. The offset calibration circuit includes a global calibration voltage generation module, integrators, comparators, a global logic control circuit, and local logic control circuits; an entire comparator array shares the single global calibration voltage generation module, and each of the comparators only needs to introduce an integrator circuit, such that a large calibration range and a small calibration step are achieved, a long calibration cycle and a large circuit area are required, and the requirements for a low area are satisfied. The offset calibration method provided by the present disclosure is similar to a binary search algorithm, which is adopted to search for the offset voltage, the calibration step of 1 2 N ? Vref can be realized by only N cycles, and short calibration time is thus realized.

Abstract: A method and apparatus are provided for efficient improved data transmissions on telephone links between service providers and remote clients. The method and apparatus perform the steps of receiving an analog encoded data signal, selectively routed by a switch which is communicatively connected to a set of central office switch assembly codecs, and performing a high precision, synchronized analog to digital conversion while the signal is relatively close to a phone company central office switch assembly. The signal is transferred to output circuitry used to transmit signals on phone company subscriber lines. The signal is converted back to an analog signal prior to its final transmission to a subscriber client modem. In an embodiment of the invention, the high precision, synchronized analog to digital conversion is performed by a client-type modem and the output is transferred to a server-type modem which transmits the converted signal, in digital form, over a pair gain system.

Abstract: A method and apparatus are provided for improved data transmissions on telephone links between service providers and remote clients. The method and apparatus perform the steps of receiving an analog encoded data signal and performing a high precision, synchronized analog to digital conversion while the signal is relatively close to a phone company central office switch assembly. The signal is transferred to output circuitry used to transmit signals on phone company subscriber lines. The signal is converted back to an analog signal prior to its final transmission to a subscriber client modem. In an embodiment of the invention, the high precision, synchronized analog to digital conversion is performed by a client-type modem and the output is transferred to a server-type modem which transmits the converted signal, in digital form, over a pair gain system.