| 摘要 |
PURPOSE:To realize a matched filter which provides high-speed data transmission with S/N maximized at the time of sampling, by adding a resistance and switch to a noise filter and then by controlling the switch in address ready mode. CONSTITUTION:A noise filter consists of series-connected resistance 8 and switch 9, and resistance 1 connected together in parallel. Switch 9, on the other hand, is turned ON-OFF by address-ready signal C from parallel-series converter 6 to change time constant (tau) of matched filter 10 over between two stages. Nearly at the switching time of analog inputs i1-in when address-ready signal C is zero, switch 9 is turned ON to insert resistance 8, and consequently even if noise would be left more or less, the time constant is decreased to shorten the response time. Around the sampling time of A/D converter 5 when address-ready signal C is one, switch 9 is OFF to increase the time constant for the maximization of SN, so that noise will completely be removed. Therefore, even if data transmission is increased in speed, the rounding of waveform never occurs. |
