| 摘要 |
<p>PURPOSE:To prevent signal degradation in the transmission path, by converting a signal from a microphone element to a digital signal in a microphone device. CONSTITUTION:Acoustic input A is converted to an electric signal by microphone element 1 and is amplified by variable amplification factor-type amplifier 2. The output of amplifier 2 is input to low-pass filter 3 and is sampled by sample hold amplifier 4 after the frequency band is limited to a prescribed range for the purpose of preventing returning distortion. Further, the sampled signal is converted to a digital signal by A/D converter 5 and is output to the outside fo microphone device 1. Amplification factor control signal 7, sample hold clock signal 8, and trigger clock signal 9 are supplied from digital signal processing device 6 to pertinent positions.</p> |
