Apparatus

An apparatus comprising:

• a transmitter element configured to generate one or both of a magnetic field or electromagnetic signal;
• a switched mode DC-DC converter configured to generate, based on a switching schedule, an output voltage for said transmitter element to generate the magnetic field or electromagnetic signal or for other components of the apparatus;
• a receiver path configured to sample a received signal over a plurality of sampling periods based on a sampling schedule;
• a noise detector configured to measure noise in the receiver path;
• a controller configured to perform a calibration process comprising:
• acquire a first measurement, by said noise detector, of noise in the receiver path for a first candidate offset setting, wherein the first candidate offset setting defines a first time offset applied to default timing of one of the switching schedule for DC-DC converter and the sampling schedule for the receiver path;
• acquire a second measurement, by said noise detector, of noise in the receiver path for a second candidate offset setting, wherein the second candidate offset setting defines a second, different, time offset applied to default timing of the one of the switching schedule for DC-DC converter and the sampling schedule for the receiver path;
• and
• select, for use in sampling the received signal, one of the first candidate offset setting and the second candidate offset setting based on which of the first measurement and the second measurement meets a noise-based criteria.

An electronic device comprising:

• a transmitter element configured to generate one or both of a magnetic field or electromagnetic signal;
• a switched mode DC-DC converter configured to generate, based on a switching schedule, an output voltage for said transmitter element to generate the magnetic field or electromagnetic signal or for other components of the apparatus;
• a receiver path configured to sample a received signal over a plurality of sampling periods based on a sampling schedule, the received signal from one of a near field communication (NFC) target and a radio frequency identifier (RFID) tag;
• a noise detector configured to measure noise in the receiver path;
• a controller configured to perform a calibration process comprising:
• acquire a first measurement, by said noise detector, of noise in the receiver path for a first candidate offset setting, wherein the first candidate offset setting defines a first time offset applied to default timing of one of the switching schedule for DC-DC converter and the sampling schedule for the receiver path;
• acquire a second measurement, by said noise detector, of noise in the receiver path for a second candidate offset setting, wherein the second candidate offset setting defines a second, different, time offset applied to default timing of the one of the switching schedule for DC-DC converter and the sampling schedule for the receiver path;
• and
• select, for use in sampling the received signal, one of the first candidate offset setting and the second candidate offset setting based on which of the first measurement and the second measurement meets a noise-based criteria.