Title:
AUTOMATIC LEVEL CONTROL SYSTEM, AND DIGITAL ELECTRONIC APPARATUS PROVIDED WITH THE SAME
Document Type and Number:
Japanese Patent JP2005159757
Kind Code:
A
Abstract:
To provide an automatic level control (ALC) system with excellent linearity capable of ensuring a wide dynamic range for an audio input signal and being configured of CMOS transistors.
A variable impedance circuit 2 configuring an attenuator together with an attenuation resistor in the ALC system is provided with: a transconductance amplifier 8 employing a CMOS transistor whose output is connected to the attenuation resistor; and a voltage division means 9 for dividing a voltage at the connecting point and giving the divided voltage to the transconductance amplifier 8.
Inventors:
KONNO CHIKASHIGE
Application Number:
JP2003395951A
Publication Date:
June 16, 2005
Filing Date:
November 26, 2003
Export Citation:
Assignee:
ROHM CO LTD
International Classes:
G10K15/04; H03G3/30; H03H11/46; (IPC1-7): H03H11/46; G10K15/04; H03G3/30
Attorney, Agent or Firm:
Tsuneo Fujikawa