Patent ID: 6177845
Filing Date: 2001-01-23
Classification: H03B,H03K,H03L

Abstract:
A frequency-providing circuit for providing an output signal at a frequency f.sub.out, the circuit comprising:a frequency-generating unit, receiving a frequency-selecting control signal, for providing a frequency output at a frequency f.sub.osc, wherein the frequency-generating unit further comprises:a first oscillator, receiving a first oscillator control signal, for providing a first frequency output at a first oscillator frequency f.sub.oscA,a second oscillator, receiving a second oscillator control signal, for providing a second frequency output at a second oscillator frequency f.sub.oscB, anda frequency-selecting unit being controlled by the frequency-selecting control signal for selecting as the frequency output one of the first frequency output or the second frequency output,said frequency-providing circuit further comprising:a frequency-changing circuit, receiving the frequency output and a frequency-changing control signal, for deriving the output signal from the received frequency output, whereby the frequency f.sub.out of the output signal can be changed with respect to the frequency f.sub.osc by the frequency-changing circuit in accordance with the frequency-changing control signal, anda synchronizing circuit for synchronizing the frequency-selecting control signal and the frequency-changing control signal,whereby the frequency-generating unit is switchable between different frequencies substantially without a settling time.