SEQUENTIAL COMPARISON TYPE AD CONVERTER, SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE MANUFACTURING METHOD, AND SEMICONDUCTOR INTEGRATED CIRCUIT DEVICE MANUFACTURING METHOD

摘要

In order to satisfy various conversion accuracies and conversion speeds required for an AD converter, it is necessary to independently configure an AD converter by matching the capacity value of the capacity group with an optimal value in accordance with a necessary conversion accuracy and a conversion speed. This increases the cost of a semiconductor integrated circuit device having a built-in AD converter. In addition to the configuration of the conventional sequential comparison type AD converter, switches (121s to 126s) are provided as capacity varying means for varying the conversion speed in accordance with the accuracy required for the sequential comparison type AD converter. With the capacity varying means, it is possible to realize a highly accurate AD converter by increasing a capacity value of one AD converter or a high-speed AD converter by reducing the capacity value. Thus, it is possible to obtain an optimal conversion time and conversion accuracy in accordance with the accuracy required in the same AD converter.