| 摘要 |
<p>A disc device signal processing device includes a VGA to which two different gain control voltages are applied and the VGA amplifies an FCM signal by the gain corresponding to the gain control voltage applied. The FCM signals amplified have peak levels detected by a peak hold circuit. According to the gain control voltages applied to the VGA and the peak levels detected by the peak hold circuit, a DSP approximates the VGA characteristic by a quadratic curve. According to this quadratic curve, an optimal gain control voltage where the optimal peak level can be obtained is calculated. The VGA amplifies the FCM signal according to the optimal gain control voltage calculated.</p> |
