Patent ID: 6297697
Filing Date: 2001-10-02
Classification: H03F

Abstract:
A signal processing circuit for processing an input signal, comprising:a frequency selective network;an amplification stage coupled to the frequency selective network, the amplification stage comprising a switching amplifier, an analog amplifier, and an output terminal;at least one continuous-time feedback path from the output terminal of the amplification stage to the frequency selective network; andswitching circuitry for alternately enabling the switching and analog amplifiers for processing of the input signal, the switching circuitry comprising level detection circuitry for monitoring a signal level indicative of the input signal, and wherein the switching circuitry is configured to alternately enable the switching and analog amplifiers in response to the signal level such that where the signal level is below a first threshold level the input signal is processed with the analog amplifier, and where the signal level is above the first threshold level the input signal is processed with the switching amplifier.