Contactless Smart Card DC-DC Conversion for Longer Operating Range
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Solution Overview
Problem
Contactless smart cards face limitations in power supply due to increased complexity and functionality, requiring closer proximity to the card terminal to derive sufficient power, which restricts their usability and processing capabilities.
Innovation Solution
Incorporating a DC-DC converter with a switched capacitive network that dynamically adjusts the input power signal to match the operating current and voltage of the card circuitry, using a step-down or step-up converter to optimize power transfer and extend operational distance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the on-card circuitry incorporates increasingly varied and complex functionality such as biometric sensors, then the functionality and processing capability of the smart card is improved, but the power requirements of the card circuitry increase, requiring the user to bring the smart card closer to the landing plane of the card terminal
Solution Approach 1:
The patent changes the electrical parameters (voltage and current) of the power signal by incorporating a DC-DC converter that can step-up or step-down the voltage and adjust the current to match the specific operating requirements of different circuitry components. This allows complex functionality to be powered effectively from the contactless interface by optimizing power delivery parameters.
Solution Approach 2:
The DC-DC converter acts as an intermediary between the contactless power reception and the card circuitry. It receives the power signal from the antenna and conditions it to appropriate voltage and current levels before delivering it to the circuitry, enabling complex components to operate at optimal power levels without requiring closer proximity to the terminal.
2Stability of the object's composition
If the voltage regulator reduces the power received from the card terminal to a common level for all constituent circuits, then all integrated circuits can operate within common operating ranges, but the processing capability is limited and transaction times increase
Solution Approach 1:
The patent replaces the static voltage regulator with a dynamic DC-DC converter that can actively adjust its output voltage and current based on the specific requirements of the connected circuitry. This dynamic adjustment capability allows different components to operate at their optimal power levels simultaneously, improving processing capability while maintaining stable operation.
Solution Approach 2:
The DC-DC converter enables independent parameter optimization for different circuitry components by adjusting voltage and current output to match each component's specific operating requirements, rather than forcing all components to operate at a common reduced power level.
3Device complexity
If a voltage regulator is used to reduce the power received from the card terminal to a level which all constituent circuits operate at, then the device complexity is reduced with a single power management component, but the power efficiency is insufficient to support complex functionalities
Solution Approach 1:
The DC-DC converter optimizes power efficiency by adjusting voltage and current parameters to match the actual power requirements of the circuitry being powered. This prevents energy waste that occurs with fixed voltage regulators that must reduce all power to a common level, thereby supporting complex functionalities with better power utilization.
Solution Approach 2:
The DC-DC converter can detect the power requirements of connected circuitry and automatically adjust its output parameters to match those requirements, enabling the power management system to adapt to different operational modes and component needs without manual intervention or complex external control.
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
The solution enhances power efficiency, allowing contactless smart cards to operate at greater distances from the card terminal and supporting more complex functionalities by increasing the current and voltage supplied to the card circuitry, thereby reducing transaction times and improving usability.
Implementation Method 1
The contactless card is powered by harvesting power from the RF signal. The contactless card may include an antenna to receive an electromagnetic signal, such as an RF signal, emitted from the card terminal.
Implementation Method 2
Near Field Communication (NFC) driver source 103 generates a driving signal which is transmitted wirelessly to smart card 102 via inductive coupling of inductive antenna 104 of card terminal 101 to inductive antenna 105 of smart card 102.
Implementation Method 3
Capacitor 106 in parallel with inductive antenna 105 act as a power coupling circuit to couple power to the card circuitry 107.
Data Source
AI summary
A smart card inlay comprising an inductive antenna and a DC-DC converter. The inductive antenna is configured to (i) communicate wirelessly with a card terminal, and (ii) power card circuitry via inductive coupling to the card terminal. The DC-DC converter has an input coupled to the inductive antenna and an output connectable to card circuitry. The DC-DC converter is configured to receive an input power signal from the inductive antenna and convert that input power signal to an output power signal to send to the card circuitry, the output power signal matching the operating current and/or operating voltage of the card circuitry.