NFC Chip Power Segmentation for Dual SIM Card Slot Operation
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Solution Overview
Problem
Mobile devices with integrated NFC chips and dual SIM cards, when powered off, can only perform NFC card reading functions using the embedded Secure Element (eSE) if a SIM card is blindly inserted, limiting functionality.
Innovation Solution
A mobile device design with an NFC chip, multiple SIM card slots, and an eSE, where a power supply unit connects to the NFC chip's second power port, allowing power to be supplied to the eSE and other SIM card slots under control of a first level signal, enabling NFC functionality using either the SIM card or eSE when the device is powered off.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the NFC chip has only two power ports and one is assigned to a SIM card slot, then the SIM card slot can be powered when needed, but the embedded Secure Element (eSE) cannot be powered simultaneously when the device is powered off
Solution Approach 1:
The power supply system is segmented into multiple independent power ports (first power port VCC and second power port VDD), allowing separate power management for different components. The first power port supplies power to one SIM card slot, while the second power port supplies power to the eSE and other SIM card slots, enabling independent operation of each component even when the main device is powered off.
Solution Approach 2:
The second power port VDD on the NFC chip is designed to serve multiple functions: it can power the eSE for NFC operations, and it can also power other SIM card slots for card reading operations. This multi-functional design allows the NFC chip to support both eSE-based NFC and SIM card-based NFC simultaneously, resolving the contradiction between reliability and adaptability.
2Loss of energy
If the mobile device is powered off, then power consumption is reduced, but the NFC card reading function cannot be implemented using SIM cards
Solution Approach 1:
The NFC chip's internal battery is pre-charged during device operation, storing energy in advance. When the device is powered off, this pre-stored energy in the internal battery immediately becomes available to power the second power port VDD, enabling SIM card reading operations without requiring the main device to be powered on. This preliminary energy storage resolves the contradiction between power saving and operational availability.
3Reliability
If the first power port supplies power to one SIM card slot, then that slot can function properly, but other SIM card slots cannot be powered when the device is powered off
Solution Approach 1:
The power distribution is segmented across two independent power ports: the first power port VCC is dedicated to powering one SIM card slot, while the second power port VDD is dedicated to powering the eSE and other SIM card slots. This segmentation allows each power port to independently manage its assigned components, enabling multiple SIM card slots to be powered simultaneously or independently based on operational needs.
Solution Approach 2:
The second power port VDD acts as an intermediary power source that bridges the gap between the NFC chip's internal battery and the other SIM card slots. It transfers and distributes power from the internal battery to the additional SIM card slots, enabling them to function independently of the first power port and the main device power state.
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
Ensures that the mobile device can perform NFC functions using either the SIM card or the eSE, even when powered off, by using the internal battery to supply power to the SIM card slot, thus maintaining functionality regardless of the SIM card's insertion slot.
Implementation Method 1
After the mobile device is powered off, a built-in battery on the NFC chip may supply power to the first power port
Data Source
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AI summary
Embodiments of the present invention provide a mobile device with an NFC function, to resolve a problem that, for a mobile device that is integrated with an NFC chip, has an eSE, and supports dual SIM cards, when a user blindly mates a SIM card, and if the mobile device is powered off, the mobile device may implement a card reading function only by using the eSE. The mobile device with the NFC function includes an NFC chip, multiple SIM card slots, a power supply unit, and an eSE integrated into the NFC chip. One SIM card slot is connected to a first power port on the NFC chip. The power supply unit is connected to a second power port on the NFC chip. When the mobile device performs near field communication, the second power port on the NFC chip is triggered to output a first level signal. Each of the rest SIM card slots is connected to the power supply unit. The eSE is connected to the power supply unit. The power supply unit is configured to: when the first level signal is received, supply power to the eSE and the SIM card slot that is connected to the power supply unit.