RFID Charge Pump Using Antenna Voltage Phases
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Solution Overview
Problem
Conventional charge pumps for RFID tags are inefficient at lower source voltages, leading to increased power consumption and reduced operating range, and can cause voltage collapse or interference with RFID communications when activated in weak RF fields.
Innovation Solution
Incorporating a charge pump into the RFID tag circuitry that uses antenna voltage phases to eliminate the need for a clock generator and reduce the number of pump stages, allowing for a higher dynamic starting voltage and reduced current consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional charge pumps are used with internally generated clock signals, then high voltage can be generated for EEPROM programming, but power consumption increases and operating range decreases
Solution Approach 1:
The charge pump circuit uses the antenna voltage phases themselves as the clock signal source, eliminating the need for separate clock generation circuitry. The antenna voltage phases directly drive the pump stages, making the system self-sufficient and reducing power consumption without compromising the operating range.
Solution Approach 2:
The invention merges the clock signal generation function with the existing antenna voltage phase detection circuitry. By using the antenna voltage phases as both the power source and the clock signal, the patent combines multiple functions into a single integrated approach, reducing overall power consumption and maintaining operating range.
2Device complexity
If charge pump clock generator and drivers are included, then charge pump operation is controlled, but die area increases and cost increases
Solution Approach 1:
The patent extracts and eliminates the separate clock generator and driver circuits from the charge pump design. By using the antenna voltage phases directly as the clock signal, the invention removes unnecessary circuit components, reducing die area and manufacturing cost while maintaining charge pump functionality.
Solution Approach 2:
The antenna voltage phases serve multiple functions: they provide power to the charge pump circuitry and simultaneously serve as the clock signal for controlling pump operations. This multi-functionality eliminates the need for separate dedicated clock generation circuitry, reducing die area and cost.
3Power
If charge pump is activated in weak RF fields, then high voltage can be generated for programming, but internal voltage may collapse causing illegal write
Solution Approach 1:
The charge pump circuit continuously monitors the antenna voltage phases and adjusts its operation accordingly. The feedback mechanism ensures that the charge pump only operates when sufficient voltage is available from the antenna, preventing voltage collapse and illegal writes while maintaining reliable programming when conditions permit.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach increases the operational range of RFID tags by reducing power consumption and die area, while enabling continued voltage scaling and minimizing interference with RFID communications.
Implementation Method 1
Voltage conversion circuitry in the RFID tag is coupled to the antenna circuitry and operable for converting a varying magnetic field induced in the antenna to a voltage source
Implementation Method 2
The charge pump is coupled to the voltage signals of the antenna circuitry which provide the charge pump with a high starting reference voltage and a two phase pump clock
Data Source
AI summary
A charge pump is incorporated into circuitry of an RFID tag. The charge pump takes advantage of an antenna voltage phase to eliminate the need for a charge pump clock generator. Placement of the charge pump in the RFID circuitry reduces the number of pump stages and eliminates drivers used in each pump stage. In some implementations, an RFID tag comprises antenna circuitry, including a tuned antenna, for receiving an RF signal. Voltage conversion circuitry in the RFID tag is coupled to the antenna circuitry and operable for converting a varying magnetic field produced in the antenna to a voltage source. A charge pump is coupled to output voltage signals of the antenna circuitry which provide the charge pump with a high starting reference voltage and a two phase pump clock.