| 摘要 |
PURPOSE:To attain compression simply to a signal not having a wide range of change for logarithmic compression by processing a current flowing to a transistor (TR) in response respectively to an input signal voltage and a reference signal voltage. CONSTITUTION:A current I1 in response to an input signal voltage VI is fed to a TR1 from a power supply VEE. A current I2 in response to a reference signal voltage VB is fed to a TR2 from the power supply VEE. Then the current I2 is nearly equal to a current IM flowing to the collector of the TR2 and a current I0 flowing to the collector of a TR8. Thus, a compressed output V0 is obtained from an output terminal 6 extracting VI-I0R0. Even a signal not having a wide range of change requiring logarithmic compression is compressed simply. |
