| 摘要 |
<p>A circuit and method for producing a signal the magnitude of which varies with the logarithm of an input signal supplied to a plurality of cascaded differential amplifier stages (10, 12, etc.) each having substantially equal gain. As particular ones of the stages go into limiting the DC rectified voltage produced at the differential common mode (22, 40, etc.) of each of the stages is detected to produce a plurality of currents. These currents are summed to the input (83) of a current turn-around circuit (84) which produces the signal at an output.</p> |
