Circuit arrangement with electronically controllable transfer characteristic

A control circuit having an electronically controllable frequency transfer characteristic comprising:

• an amplifier having first and second inputs and a controllable negative feedback,
• a signal input terminal coupled to the first input of the amplifier,
• a signal output terminal,
• a frequency-dependent voltage divider coupled to an output of the amplifier and having a plurality of taps connectable to the second input of the amplifier via a first controllable switch and to said signal output terminal via a second controllable switch, wherein
• the first and second switches are controlled in a manner such that for boosting the input signal in a frequency band determined by the frequency-dependent voltage divider
• the first switch is set to a tap position such that boosting is effected with the desired frequency bandwidth, and that
• the tap position of the second switch is selected so as to obtain boosting to the desired degree, and that
• for attenuating the input signal in the frequency band determined by the frequency-dependent voltage divider
• the second switch is set to a tap position such that attenuation is effected with the desired frequency bandwidth, and that
• the first switch is set to a tap position so as to obtain attenuation to the desired degree.

A method of controlling the frequency transfer characteristic of a circuit which comprises an amplifier having a controllable negative feedback and connected to a frequency-dependent voltage-divider circuit which includes plural taps connectable to an input of the amplifier via a first controllable switch and to a circuit output via a second controllable switch, said method comprising:

• in order to boost an amplifier input signal in a frequency band determined by the frequency-dependent voltage divider;
• controlling the first switch to a tap position at which boosting is effected with a desired frequency bandwidth, and
• controlling the second switch to a tap position which produces the desired degree of boosting, and
• in order to attenuate the input signal in the frequency band determined by the frequency-dependent voltage divider;
• controlling the second switch to a tap position at which attenuation is effected with a desired frequency bandwidth, and
• controlling the first switch to a tap position which produces the desired degree of attenuation.