Radio frequency data communications device
First Claim
Patent Images
1. A radio frequency identification device comprising:
- an integrated circuit including a transmitter and a receiver, the integrated circuit being adapted to be coupled to a battery, and further including a comparator configured to compare the voltage of the battery with a predetermined voltage and to generate a low battery signal if the voltage of the battery is less than the predetermined voltage, the integrated circuit further including a band gap voltage generator configured to generate a reference voltage, the predetermined voltage being the reference voltage produced by the band gap voltage generator;
a wake-up circuit configured to activate the receiver from time to time so the receiver can listen for any RF command from an interrogator; and
a power-up circuit configured to provide a power-up signal to the processor in response to determining that the receiver received a valid RF signal.
3 Assignments
0 Petitions
Accused Products
Abstract
A radio frequency identification device comprises an integrated circuit including a receiver, a transmitter, and a microprocessor. The receiver and transmitter together define an active transponder. The integrated circuit is preferably a monolithic single die integrated circuit including the receiver, the transmitter, and the microprocessor. Because the device includes an active transponder, instead of a transponder which relies on magnetic coupling for power, the device has a much greater range.
-
Citations
25 Claims
-
1. A radio frequency identification device comprising:
-
an integrated circuit including a transmitter and a receiver, the integrated circuit being adapted to be coupled to a battery, and further including a comparator configured to compare the voltage of the battery with a predetermined voltage and to generate a low battery signal if the voltage of the battery is less than the predetermined voltage, the integrated circuit further including a band gap voltage generator configured to generate a reference voltage, the predetermined voltage being the reference voltage produced by the band gap voltage generator; a wake-up circuit configured to activate the receiver from time to time so the receiver can listen for any RF command from an interrogator; and a power-up circuit configured to provide a power-up signal to the processor in response to determining that the receiver received a valid RF signal. - View Dependent Claims (2)
-
-
3. A radio frequency identification device comprising:
an integrated circuit including a transmitter and a receiver, the integrated circuit being adapted to be coupled to a battery, and further including a comparator configured to compare the voltage of the battery with a predetermined voltage and to generate a low battery signal if the voltage of the battery is less than the predetermined voltage, the integrated circuit further including a band gap voltage generator configured to generate a reference voltage, the predetermined voltage being the reference voltage produced by the band gap voltage generator, the integrated circuit being configured to respond to commands received by the receiver from an interrogator, the integrated circuit further including a status register having, in operation, a value indicating whether battery voltage is less than the predetermined voltage, and the transmitter being configured to transmit the value of the status register in response to a command received by the receiver. - View Dependent Claims (4)
-
5. A radio frequency identification device comprising:
-
an integrated circuit including ROM, a processor, a transmitter and a receiver, the ROM, the transmitter and receiver being coupled to the processor, the integrated circuit having a power input terminal configured to be coupled to a battery; a wake-up circuit configured to periodically activate the receiver, the wake-up circuit being coupled to the receiver and the processor and periodically waking the receiver using a sleep interval derived by the processor from received commands, the wake-up circuit being configured to determine when a valid command is being received and to supply electrical power from the battery to the processor in response thereto; a power-up circuit configured to provide a power-up signal in response to determination of reception of a valid interrogation signal by the wake-up circuit, the power-up signal being reset in response to the processor completing a wake-up program stored in ROM including resetting of the wake-up circuit; and a low battery detection circuit configured to be coupled to the battery and configured to provide a signal indicative of battery voltage having fallen below a predetermined limit in response to the power-up signal being reset and the battery voltage having fallen below the predetermined limit, the low battery detection circuit having an output coupled to the processor for setting a data bit indicative of battery status responsive to resetting of the power-up signal. - View Dependent Claims (6, 7, 8)
-
-
9. A radio frequency identification device comprising:
-
an integrated circuit including a processor, a transmitter and a receiver, the transmitter and receiver being coupled to the processor, the integrated circuit having a power input terminal configured to be coupled to a battery; a power-up circuit configured to provide a power-up signal in response to determination of reception of a valid interrogation signal, the power-up signal being reset when the processor completes a wake-up routine; and a low battery detection circuit configured to be coupled to the battery and configured to provide a signal indicative of battery voltage having fallen below a predetermined limit in response to the power-up signal being reset, the low battery detection circuit being configured to set a data bit indicative of battery status responsive to resetting of the power-up signal. - View Dependent Claims (10, 11, 12, 13, 14)
-
-
15. A method of operating a radio frequency device comprising:
-
coupling an integrated circuit including ROM, a processor, a transmitter and a receiver to a battery, the ROM, the transmitter and receiver being coupled to the processor; selectively supplying electrical power from the battery to the receiver at predetermined intervals by control signals from a wake-up circuit; determining, by a wake-up circuit coupled to the processor and receiver, when a valid command is being received and supplying electrical power from the battery to the processor in response thereto; providing a power-up signal from a power-up circuit in response to determination of reception of a valid interrogation signal by the wake-up circuit; resetting the power-up signal in response to the processor completing a wake-up program stored in ROM including resetting of the wake-up circuit; and providing a signal from a low battery detection circuit indicative of battery voltage having fallen below a predetermined limit in response to the resetting, the low battery detection circuit having an output coupled to the processor for setting a data bit indicative of battery status responsive to resetting of the power-up signal. - View Dependent Claims (16, 17, 18, 19)
-
-
20. A method of operating a radio frequency device comprising:
-
coupling an integrated circuit including a processor, a transmitter and a receiver to a battery, the transmitter and receiver being coupled to the processor; selectively supplying electrical power from the battery to the receiver at predetermined intervals by control signals from a wake-up circuit coupled to the receiver and the processor; determining, by the wake-up circuit, when a valid command is being received and supplying electrical power from the battery to the processor in response thereto; providing a power-up signal from a power-up circuit in response to determination of reception of a valid interrogation signal by the wake-up circuit; resetting the power-up signal when the processor completes a wake-up routine including resetting of the wake-up circuit; and providing a signal from a low battery detection circuit indicative of battery voltage having fallen below a predetermined limit in response to resetting, the low battery detection circuit having an output coupled to the processor for setting a data bit indicative of battery status responsive to resetting of the power-up signal. - View Dependent Claims (21, 22, 23, 24, 25)
-
Specification