Communication cell for an integrated circuit operating in contact and contactless mode, electronic chip comprising the communication cell, electronic system including the chip, and test apparatus

A communication method for an integrated circuit, comprising the steps of:

• receiving, by a physical interface coupled to a first input terminal of the communication cell, an input signal, wherein, in a first operating condition, said input signal is a first operating signal supplied by a capacitive-signal source capacitively coupled to the physical interface and, in a second operating condition, said input signal is a second operating signal supplied by an ohmic-signal source ohmically coupled to the physical interface;
• and
• in the second operating condition, receiving by a buffer said second operating signal and generating a third intermediate signal correlated to said second operating signal,
• in the first operating condition, receiving and amplifying, by a second receiver circuit including a transimpedance-amplifier circuit, said first operating signal, thus generating a first intermediate signal;
• and
• receiving, by a selector device, the first intermediate signal and the second intermediate signal, and making available to said integrated circuit only the first intermediate signal in the first operating condition and only the second intermediate signal in the second operating condition.

A circuit, comprising:

• a first input/output node configured to be coupled to a communications interface;
• an input node configured to be coupled to an output of an integrated circuit;
• an output node configured to be coupled to an input of the integrated circuit;
• a driving circuit coupled between the input node and the input/output node;
• a buffer circuit having an input coupled to the input/output node and an output;
• a capacitive communication receive circuit having an input coupled to the input/output node and an output;
• an inductive communication receive circuit having an input coupled to the input/output node and an output;
• a switching circuit having inputs coupled to the outputs of the capacitive and inductive communication receive circuits and having an output;
• a multiplexer having inputs coupled to the outputs of the switching circuit and the buffer circuit and having an output coupled to the output node;
• a first selection input configured to receive a first selection signal for controlling operation of the switching circuit to selectively coupled the output of the switching circuit to a selected one of the outputs of the capacitive and inductive communication receive circuits;
• and
• a second selection input configured to receive a second selection signal for controlling operation of the multiplexer to select between a signal at the output of the buffer circuit and a signal at the output of the switching circuit.

A communication cell, comprising:

• a physical interface coupled to a first input terminal of the communication cell and configured to supply to the first input terminal an input signal,
• wherein, in a first operating condition, said input signal is a first operating signal supplied by a capacitive-signal source and, in a second operating condition, said input signal is a second operating signal supplied by an ohmic-signal source;
• and
• a first receiver circuit including a buffer configured to form an interface for reception of said second operating signal and generation of a second intermediate signal correlated to said second operating signal;
• a second receiver circuit including a transimpedance-amplifier circuit operatively coupled to said capacitive-signal source and configured to receive and amplify said first operating signal to generate a first intermediate signal;
• an output stage configured to be coupled to said integrated circuit and including a selector device configured to receive the first intermediate signal and the second intermediate signal and to make available to said integrated circuit only the first intermediate signal in the first operating condition and only the second intermediate signal in the second operating condition;
• wherein, in a third operating condition, said input signal is a third operating signal supplied by an inductive-signal source, said communication cell further comprising:
• a third receiver circuit including a differential-amplifier circuit configured to be operatively coupled to said inductive-signal source to receive and amplify said third operating signal to generate a third intermediate signal,
• wherein said selector device is further configured to receive the third intermediate signal and to make available to said integrated circuit only one from among the first intermediate signal, the second intermediate signal, and the third intermediate signal during the respective first, second, and third operating conditions.

A communication cell, comprising:

• a physical interface coupled to a first input terminal of the communication cell and configured to supply to the first input terminal an input signal,
• wherein, in a first operating condition, said input signal is a first operating signal supplied by a capacitive-signal source and, in a second operating condition, said input signal is a second operating signal supplied by an ohmic-signal source;
• a first receiver circuit including a buffer configured to form an interface for reception of said second operating signal and generation of a second intermediate signal correlated to said second operating signal;
• a second receiver circuit including a transimpedance-amplifier circuit operatively coupled to said capacitive-signal source and configured to receive and amplify said first operating signal to generate a first intermediate signal;
• an output stage configured to be coupled to said integrated circuit and including a selector device configured to receive the first intermediate signal and the second intermediate signal and to make available to said integrated circuit only the first intermediate signal in the first operating condition and only the second intermediate signal in the second operating condition;
• and
• a detection circuit configured to detect the first and second operating modes, including:
• an input stage configured to generate an operating signal that has a first value in the first operating condition and a second value, different from the first value, in the second operating condition;
• and
• a comparator configured to receive the operating signal and a comparison signal and to output a control signal representing one of the first operating condition or the second operating condition.

A communication cell, comprising:

• a physical interface coupled to a first input terminal of the communication cell and configured to supply to the first input terminal an input signal,
• wherein, in a first operating condition, said input signal is a first operating signal supplied by a capacitive-signal source and, in a second operating condition, said input signal is a second operating signal supplied by an ohmic-signal source;
• and
• a first receiver circuit including a buffer configured to form an interface for reception of said second operating signal and generation of a second intermediate signal correlated to said second operating signal;
• a second receiver circuit including a transimpedance-amplifier circuit operatively coupled to said capacitive-signal source and configured to receive and amplify said first operating signal to generate a first intermediate signal;
• wherein the transimpedance-amplifier circuit comprises an operational amplifier having an inverting input coupled to the first input terminal for receiving the input signal, a non-inverting input biased to a reference voltage, and a feedback branch including a resistor which electrically couples an output terminal of the operational amplifier to the inverting input;
• and
• the second receiver circuit further comprising a hysteresis threshold comparator configured to restore the logic levels of the signal supplied at output from the transimpedance amplifier and generate said first intermediate signal correlated to the first operating signal;
• an output stage configured to be coupled to said integrated circuit and including a selector device configured to receive the first intermediate signal and the second intermediate signal and to make available to said integrated circuit only the first intermediate signal in the first operating condition and only the second intermediate signal in the second operating condition.

A communication method for an integrated circuit, comprising the steps of:

• receiving, by a physical interface coupled to a first input terminal of the communication cell, an input signal, wherein, in a first operating condition, said input signal is a first operating signal supplied by a capacitive-signal source and, in a second operating condition, said input signal is a second operating signal supplied by an ohmic-signal source;
• in the second operating condition, receiving by a buffer said second operating signal and generating a third intermediate signal correlated to said second operating signal,
• in the first operating condition, receiving and amplifying, by a second receiver circuit including a transimpedance-amplifier circuit, said first operating signal, thus generating a first intermediate signal;
• receiving, by a selector device, the first intermediate signal and the second intermediate signal, and making available to said integrated circuit only the first intermediate signal in the first operating condition and only the second intermediate signal in the second operating condition;
• wherein, in a third operating condition, said input signal is a third operating signal supplied by an inductive-signal source;
• in the third operating condition, receiving and amplifying said third operating signal, thus generating a third intermediate signal;
• and
• receiving, by the selector device, the third intermediate signal and making available to said integrated circuit only one from among the first intermediate signal, the second intermediate signal and the third intermediate signal in the respective first, second, and third operating conditions.

A communication method for an integrated circuit, comprising the steps of:

• receiving, by a physical interface coupled to a first input terminal of the communication cell, an input signal, wherein, in a first operating condition, said input signal is a first operating signal supplied by a capacitive-signal source and, in a second operating condition, said input signal is a second operating signal supplied by an ohmic-signal source;
• in the second operating condition, receiving by a buffer said second operating signal and generating a third intermediate signal correlated to said second operating signal,
• in the first operating condition, receiving and amplifying, by a second receiver circuit including a transimpedance-amplifier circuit, said first operating signal, thus generating a first intermediate signal;
• receiving, by a selector device, the first intermediate signal and the second intermediate signal, and making available to said integrated circuit only the first intermediate signal in the first operating condition and only the second intermediate signal in the second operating condition;
• generating an operating signal that assumes a first value in the first operating condition and a second value, different from the first value, in the second operating condition;
• and
• generating, by a comparator, on the basis of the operating signal and of a comparison signal, a control signal representing the first operating condition or the second operating condition.