Frequency-providing circuit

A frequency-providing circuit for providing an output signal at a frequency fout, the circuit comprising:

• a frequency-generating unit, receiving a frequency-selecting control signal, for providing a frequency output at a frequency fosc, 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 foscA,
• a second oscillator, receiving a second oscillator control signal, for providing a second frequency output at a second oscillator frequency foscB, and
• a 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 fout of the output signal can be changed with respect to the frequency fosc by the frequency-changing circuit in accordance with the frequency-changing control signal, and
• a 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.