A frequency determination device for determining a frequency relationship between a reference signal and a clock signal. Each constituent TDC is configured to provide a digitally represented constituent output signal in response to receiving a constituent reference signal and a constituent clock signal, and the frequency determination device is configured to successively provide respectively delayed versions of the constituent clock signal of a first constituent TDC as respective constituent clock signals to the other constituent TDC:s. The reference signal provider is configured to provide the respective constituent reference. The switching circuitry is configured to provide the reference signal as the constituent clock signal to the first constituent TDC. The determination circuitry is configured to determine a number of consecutively same-valued symbols in a concatenation of the digitally represented constituent output signals of the constituent TDC:s, and to determine the frequency relationship.