An integrated sensor (5A-5C; 205A-205C), the integrated sensor being configured to receive a frequency-indication signal (S U, EXT_REF; REF1, REF2) and to supply an output digital signal (S O) including a plurality of samples, the integrated sensor comprising: a digital detector, configured to detect a physical quantity and generate a discrete detection signal (S D) indicative of the detected physical quantity; an output timing regulation block (80, 83), configured to receive the frequency-indication signal (S U, EXT_REF; REF1, REF2) and a set of local reference signals (CLK, INT_REF) and to generate a trigger signal (OUT_TRG) as a function of the frequency-indication signal and of the set of local reference signals; and an output stage, configured to receive the discrete detection signal and the trigger signal (OUT_TRG) and to supply the digital output signal (S O) and a locking signal (EXT_REF, INT_REF; REF1, REF2), wherein the output stage is configured to supply a sample of the discrete detection signal in response to the reception of the trigger signal, thereby generating the digital output signal, and to supply the locking signal in response to the reception of the trigger signal, the locking signal being temporally aligned with the digital output signal, wherein the integrated sensor is configured to be used as a reference sensor and/or as a slave sensor of an electronic apparatus (1; 200) comprising a plurality of integrated sensors (5; 205), the integrated sensor being configured, when used as reference sensor (5A; 205A, 205B), to provide at output the respective locking signal as external reference signal (EXT_REF; REF1, REF2) for use as frequency-indication signal by a slave sensor (5B, 5C; 205C) of the plurality of integrated sensors, the integrated sensor being configured, when used as slave sensor (5B, 5C; 205B), to use the respective locking signal as local reference signal (INT_REF; REF2). a digital detector, configured to detect a physical quantity and generate a discrete detection signal (S D) indicative of the detected physical quantity; an output timing regulation block (80, 83), configured to receive the frequency-indication signal (S U, EXT_REF; REF1, REF2) and a set of local reference signals (CLK, INT_REF) and to generate a trigger signal (OUT_TRG) as a function of the frequency-indication signal and of the set of local reference signals; and an output stage, configured to receive the discrete detection signal and the trigger signal (OUT_TRG) and to supply the digital output signal (S O) and a locking signal (EXT_REF, INT_REF; REF1, REF2), wherein the output stage is configured to supply a sample of the discrete detection signal in response to the reception of the trigger signal, thereby generating the digital output signal, and to supply the locking signal in response to the reception of the trigger signal, the locking signal being temporally aligned with the digital output signal, wherein the integrated sensor is configured to be used as a reference sensor and/or as a slave sensor of an electronic apparatus (1; 200) comprising a plurality of integrated sensors (5; 205), the integrated sensor being configured, when used as reference sensor (5A; 205A, 205B), to provide at output the respective locking signal as external reference signal (EXT_REF; REF1, REF2) for use as frequency-indication signal by a slave sensor (5B, 5C; 205C) of the plurality of integrated sensors, the integrated sensor being configured, when used as slave sensor (5B, 5C; 205B), to use the respective locking signal as local reference signal (INT_REF; REF2).