Abstract: A successive-approximation register (SAR) analog-to-digital converter (ADC) circuit includes a comparator circuit and a plurality of latch circuits. The comparator circuit is configured to compare an analog signal with a plurality of reference levels. The latch circuits, coupled to the comparator circuit and connected in series, are triggered sequentially in response to a plurality of trigger signals, respectively, to store a comparator output of the comparator circuit and accordingly generate a digital signal. A first latch circuit and a second latch circuit of the latch circuits are triggered in response to a first trigger signal and a second trigger signal of the trigger signals, respectively. The first latch circuit is configured to generate the second trigger signal according to the comparator output stored in the first latch circuit.

Abstract: A file protection method is used for preventing files stored in a solid state disc array system from being reproduced unauthorizedly. After a file is produced completely, it is stored in a solid state disc array system connected to an external computer. When the external computer is to execute the files stored in the solid state disc array system, it checks the files and parameters (e.g. key password or serial number) set in the solid state disc array system step by step. Only when all of the parameters are correct and correspond to one another, the files can be executed normally. In this way, the files can be protected from being copied unauthorizedly.