Radio frequency data communications device

A method of operating a radio frequency device comprising an integrated circuit including a microprocessor, a receiver configured to receive radio frequency commands from an interrogation device, the receiver including an amplifier, the receiver having an output coupled to the microprocessor, and a wake-up timer circuit coupled to the receiver and configured to determine when a signal received by the receiver is a radio frequency command from the interrogation device, the method comprising:

• switching the integrated circuit between a sleep mode and a receiver on mode, more power being consumed in the receiver on mode than in the sleep mode;
• determining when the signal received by the receiver is a radio frequency command from the interrogation device;
• and
• switching the integrated circuit to a microprocessor on mode from the receiver on mode when the integrated circuit determines that the signal received by the receiver is a radio frequency command from the interrogation device, more power being consumed in the microprocessor on mode than in the receiver on mode.

A method of operating a radio frequency device comprising an integrated circuit including a microprocessor, a receiver configured to receive radio frequency commands from an interrogation device, the receiver including an amplifier, the receiver having an output coupled to the microprocessor, and a wake-up timer circuit coupled to the receiver and configured to determine when a signal received by the receiver is a radio frequency command from the interrogation device, the method comprising:

• switching the integrated circuit between a sleep mode and a receiver on mode, more power being consumed in the receiver on mode than in the sleep mode;
• determining when the signal received by the receiver is a radio frequency command from the interrogation device;
• switching the integrated circuit to a microprocessor on mode from the receiver on mode when the integrated circuit determines that the signal received by the receiver is a radio frequency command from the interrogation device, more power being consumed in the microprocessor on mode than in the receiver on mode;
• and
• powering the amplifier by a selectively engageable voltage source engaged in the receiver on mode but not in the sleep mode, the amplifier including first and second inputs for receiving an input signal to be amplified, the inputs respectively including coupling capacitors, the amplifier including a differential amplifier having inputs respectively connected to the first and second inputs through the coupling capacitors, and having an output.

An integrated circuit comprising:

• a microprocessor;
• a receiver configured to receive radio frequency commands from an interrogation device and having an output coupled to the microprocessor, the receiver including an amplifier powered by a selectively engageable voltage source;
• and
• a control circuit coupled to the receiver and the microprocessor, the control circuit being configured to:
• determine when a signal received by the receiver is a radio frequency command from the interrogation device;
• switch the integrated circuit between a sleep mode and a receiver on mode, more power being consumed in the receiver on mode than in the sleep mode;
• and
• switch the integrated circuit from the receiver on mode to a microprocessor on mode in response determining that the signal received by the receiver is a radio frequency command from the interrogation device, more power being consumed in the microprocessor on mode than in the receiver on mode.

A radio frequency device comprising an integrated circuit including a microprocessor, a receiver configured to receive radio frequency commands from an interrogation device and having an output coupled to the microprocessor, a transmitter configured to transmit a signal identifying the device to the interrogator in response to a command from the microprocessor, and a wake-up timer circuit coupled to the receiver and configured to determine when a signal received by the receiver is a radio frequency command from the interrogation device, the radio frequency command from the interrogator including data transition pulses, the integrated circuit at times switching between a sleep mode and a receiver on mode, more power being consumed in the receiver on mode than in the sleep mode, the integrated circuit switching from the receiver on mode to a microprocessor on mode when logic in a wake-up timer circuit determines that a signal received by the receiver is a radio frequency command from the interrogation device, the logic configured to perform a plurality of tests, each test including counting at least some of the data transition pulses, the determination being made in response to the plurality of tests, the receiver further including an amplifier powered by a selectively engageable voltage source engaged in the receiver on mode but not in the sleep mode, the amplifier including first and second inputs for receiving an input signal to be amplified, the inputs respectively including coupling capacitors, a differential amplifier having inputs respectively connected to the first and second inputs through the coupling capacitors, and having an output, selectively engageable resistances between the voltage source and respective inputs of the differential amplifier, second selectively engageable resistances between the voltage source and respective inputs of the differential amplifier, the second resistances respectively having smaller values than the first mentioned resistances, the second resistances being engaged then disengaged in response to the integrated circuit switching from the sleep mode to the receiver on mode.

A method of operating a radio frequency device comprising an integrated circuit including a microprocessor, a receiver configured to receive radio frequency commands from an interrogation device, the radio frequency commands including data transition pulses, the receiver including an amplifier, the receiver having an output coupled to the microprocessor, the integrated circuit including a transmitter configured to transmit a signal identifying the device to the interrogator in response to commands from the microprocessor and a wake-up timer circuit coupled to the receiver and configured to determine when a signal received by the receiver is a radio frequency command from the interrogation device, the method comprising:

• switching the integrated circuit between a sleep mode and a receiver on mode, more power being consumed in the receiver on mode than in the sleep mode;
• powering the amplifier by a selectively engageable voltage source engaged in the receiver on mode but not in the sleep mode, the amplifier including first and second inputs for receiving an input signal to be amplified, the inputs respectively including coupling capacitors, the amplifier including a differential amplifier having inputs respectively connected to the first and second inputs through the coupling capacitors, and having an output;
• engaging first selectively engageable resistances between the voltage source and respective inputs of the differential amplifier;
• engaging second selectively engageable resistances between the voltage source and respective inputs of the differential amplifier, the second resistances respectively having smaller values than the first mentioned resistances, the second resistances being engaged then disengaged in response to the integrated circuit switching from the sleep mode to the receiver on mode;
• and
• performing a plurality of tests using the wake-up timer circuit, each test including counting data transition pulses, and making the determination in response to the plurality of tests.