The invention relates to the creation of a precise frequency standard (5) in an integrated circuit, by activating a reference oscillator (6) at specific intervals and by calibrating the local oscillator (2). To achieve this, a calibration circuit (8), which determines the pulse ratio between the internal clock pulse (3) and the reference clock pulse (7), is provided. The pulse ratio that has been determined is used to programme a frequency divider (4). The invention is particularly suitable for use in mobile radio devices. |