Receiver circuit

A data communications receiver, comprising:

• a receiver coil;
• filter circuitry coupled to filter low frequency components from a signal received by the receiver coil and output a filtered signal;
• amplification circuitry coupled to receive the filtered signal and to amplify differences between the filtered signal relative to a threshold;
• and
• hysteretic level shifting circuitry to shift a level of
• a) part of the filtered signal received by the receiver coil,
• b) the threshold, or
• c) both part of the filtered signal and the threshold
• such that, in response to the filtered signal having crossed the threshold, a threshold crossing in the other direction is delayed.

A data communications receiver, comprising:

• a receiver coil;
• a first amplification stage coupled to the receiver coil, the first amplification circuitry to amplify a difference between
• a) at least part of signal received by the receiver coil and
• b) a threshold;
• a current amplification circuit having an input coupled to receive the amplified difference from the first amplification;
• and
• hysteretic level shifting circuitry to shift a level of
• a) part of the filtered signal received by the receiver coil,
• b) the threshold, or
• c) both part of the filtered signal and the threshold
• such that, in response to the at least part of the signal received by the receiver coil having crossed the threshold, a threshold crossing in the other direction is delayed.