METHOD AND APPARATUS FOR CONTROLLING THE RATIO OF AN OUTPUT SIGNAL AND AN INPUT SIGNAL

摘要

The operating ratio of an input signal and an output signal of a device (for example, the gain of an amplifier) is controlled by the use of two signals having respective levels corresponding to the input and output signal levels. The ratio is controlled to a target value based on a difference between the two signals, without the need for either a reference signal representing the target value or a division operation to calculate the operating ratio. In a preferred mode, the two signals are produced by corresponding amplifier units which have known gains and which are connected, respectively, to the input and the output of the device.