Equipment for contactless communication with terminals

Abstract

A device for contactless communication with a terminal, the device comprising: an antenna for receiving a wireless signal emitted by the terminal; an embedded chip configured to generate data for communicating with the terminal to perform a first function associated with the device; and a module separate from the chip, configured to perform processing as part of a second function associated with the device, the module being connected to the antenna and comprising a power collection unit, the power collection unit being configured to collect power from the received wireless signal to at least power the module.

Description

Technical Field

[0001] The present invention relates to the architecture of a multifunctional device. In particular, certain aspects relate to the architecture of a device capable of operating in a contactless mode of operation. Background Art

[0002] A smart card may refer to a device that includes an embedded integrated circuit chip and internal memory. The internal memory may be located on the integrated circuit chip, or may be a separate chip embedded within the card. A smart card may be a contact card; a contactless card, or may be capable of operating as both a contact card and a contactless card. Smart cards exist in a variety of form factors, including plastic cards, key fobs, watches, wearable devices, electronic passports, and USB-based tokens and subscriber identity modules (SIMs) used in mobile phones.

[0003] A contact card communicates with a terminal (e.g., a card reader) by being physically connected to the terminal. For example, a contact card may include one or more contact pads that provide an electrical connection to the terminal when the card and the terminal make appropriate physical contact (e.g., by inserting the card into a slot in the terminal).

[0004] Contactless cards communicate with terminals without direct physical contact. Typically, contactless cards communicate with terminals via radio waves. Contactless cards may include an antenna for receiving electromagnetic signals (e.g., RF signals) emitted from the terminal. Similarly, data from the card can be transmitted back to the terminal by means of the card's antenna.

[0005] Some contactless cards are "passive". A passive card will power the embedded chip with energy harvested from the signal emitted by the terminal. One way to harvest energy from the emitted signal is to arrange the antenna as a coil which induces a voltage across its terminals by induction when it receives the emitted signal.

[0006] Smart card technology is implemented in a variety of devices that are used to perform an ever-changing range of functions, such as to perform payments, grant physical access to areas of an environment, store personal identity information of a user, identify or authenticate a user, etc. In some cases, it may be desirable for a device to be able to perform multiple different functions.

[0007] Several difficulties are faced when attempting to implement multiple functions into a device using smart card technology, particularly when a device designed to perform a "basic" or primary function is adapted to perform additional functions. One problem is that the industry standards governing smart card technology were originally designed for payment / authentication cards. As a result, the existing infrastructure was designed in accordance with these standards and is suitable for powering this primary function of facilitating payments or transactions, which can impose constraints on the power that can be consumed by any additional functions placed on the card. This problem can be further complicated by the fact that additional functions can consume more power and / or require longer periods of time than the primary function of the card. Another problem is that for cards operating in contactless mode, the power drawn by the additional functions can affect the load modulation of the signal emitted by the terminal, which can introduce additional noise to the terminal. Summary of the invention

[0008] According to the present invention, there is provided a device for contactless communication with a terminal, the device comprising:

[0009] An antenna, used to receive a wireless signal sent by the terminal;

[0010] an embedded chip configured to generate data for communicating with the terminal to perform a first function associated with the device; and

[0011] A module separate from the chip is configured to perform processing as part of a second function associated with the device, the module is connected to the antenna and includes a power collection unit, the power collection unit is configured to collect power from the received wireless signal to power at least the module.

[0012] The module may be connected to the chip via a link, the module comprising a power management unit configured to control transmission of harvested power to power the chip.

[0013] The module may be configured to manage the transmission and reception of messages with the reader, the messages containing data generated by the chip.

[0014] The chip may be connected to the antenna and include a power harvesting unit configured to harvest power from received wireless signals to power the chip.

[0015] The module may be configured to harvest power from received wireless signals independently of the chip.

[0016] The modules and chips may each include a dedicated microcontroller unit (MCU).

[0017] The device may be configured such that only the chip is arranged to manage message transmission and reception with the terminal.

[0018] The device may be configured such that only the chip is adapted to communicate messages with the terminal via the antenna.

[0019] The chip may include a modem configured to extract data from a received wireless signal transmitted from the terminal.

[0020] The modem may also be configured to modulate data generated by the chip onto the signal sent by the terminal to transmit the data to the terminal.

[0021] The device may be used for contact and contactless communication with the terminal, and may further include:

[0022] At least one contact element is connected to the embedded chip and the module and is arranged to supply power from the terminal to the embedded chip and the module when the device is in contact communication with the terminal.

[0023] The module may also include a noise mitigation circuit configured to store charge using power harvested from received wireless signals when the device comes within range of the terminal.

[0024] The noise mitigation circuit may be configured to provide current required by one or more components of the module to inhibit current drawing from the antenna during operation of those components.

[0025] The noise mitigation circuit may be located within the power harvesting unit.

[0026] The noise mitigation circuit may comprise one or more charging elements for storing electrical charge, the charging elements being arranged to discharge to provide the required current.

[0027] The noise mitigation circuit may include a rectifier circuit coupled to the antenna and configured to output a rectified voltage to charge the first charging element.

[0028] The noise mitigation circuit may further include a power regulation circuit configured to output a regulated voltage to charge the second charging element.

[0029] The noise mitigation circuit may also include a control block configured to control an amount of current provided from the charging element to the one or more components based on a deviation from a required current of those components.

[0030] The noise mitigation circuit may include a first voltage regulator coupled to the rectifier circuit and a first component of the module and a second voltage regulator coupled to the rectifier circuit and a second component of the module, the first voltage regulator being configured to output a different regulated voltage level than the second voltage regulator.

[0031] The first component of the module may be an ASIC configured to control a sensor forming part of the module, and the second component of the module may be a microcontroller unit.

[0032] The first voltage regulator may be configured to output a higher regulated voltage than the second voltage regulator.

[0033] The first voltage regulator may be a low dropout regulator and the second voltage regulator may be a switch mode power supply.

[0034] The noise mitigation circuitry may be located locally at a component of the module.

[0035] The chip may be a secure element.The chip may be a first integrated circuit chip, and the module may be implemented on a second integrated circuit chip.

[0036] The module may be a biometric sensor module.

[0037] The device may be configured to communicate with the terminal according to ISO 14443 and / or ISO 7816 standards.

[0038] The first function may be one of the following: ID verification; physical access control; financial transaction; personal information retrieval; health record retrieval.

[0039] The second function may be biometric authentication of the user.

[0040] The device may be a contactless card and the terminal may be a point of sale terminal.

[0041] Also provided is a device for communicating with a terminal in a contact or contactless operation mode, the device comprising:

[0042] An antenna, used to receive wireless signals sent by the terminal;

[0043] an embedded chip configured to generate data for communicating with the terminal to perform a first function associated with the device;

[0044] a biometric sensor module, separate from the chip and configured to perform processing forming part of the biometric sensing of a user characteristic, the module being connected to the antenna and comprising a power harvesting unit configured to harvest power from the received wireless signal to power one or more internal components of the module when the device is operating in the contactless mode of operation; and

[0045] one or more contact elements configured to supply power from a terminal to the biometric sensor module when the device is operating in the contact mode of operation;

[0046] The biometric sensor module further comprises a power regulation circuit coupled to at least one of the one or more contact elements, the power collection unit, and the internal components of the module; the power regulation circuit comprising:

[0047] a circuit path coupled at a first end to the one or more contact elements and at a second end to the power harvesting unit and the at least one internal component of the module;

[0048] a switching element interconnecting a first portion of the circuit path including the first end and a second portion of the circuit path including the second end;

[0049] a bypass circuit providing a path around the switching element, the bypass circuit allowing current to flow in a direction from a first end to a second end of the circuit; and

[0050] a coupling unit coupled to the first portion of the circuit path and the switching element;

[0051] The circuit is arranged so that: when the card operates in contact mode, the power provided by the contact element drives the switch element to an open circuit configuration via the coupling unit, thereby limiting the current flowing from the first end of the circuit to the second end of the circuit through the bypass circuit; and when the card operates in contactless mode, the power collected by the power collection unit causes the switch element to adopt an open circuit configuration, thereby preventing the current from flowing from the second end of the circuit to the first end of the circuit.

[0052] The bypass circuit may include a diode that limits current flow in a direction from the first portion of the circuit to the second portion of the circuit. The bypass circuit may also include one or more resistor elements arranged in series with the diode.

[0053] The power regulation circuit may include only a single switching element. The switching element may be a bipolar transistor. The switching element may be a PNP transistor. The emitter of the transistor may be electrically connected to the first portion of the circuit path, and the collector may be electrically connected to the second portion of the circuit path.

[0054] The power regulation circuit may also include a low pass filter. The bypass circuit may form part of the low pass filter, thereby limiting the current flowing through the low pass filter from the first end of the circuit to the second end of the circuit when the card is in contact communication with the terminal and the switch element is in an open circuit configuration.

[0055] The coupling unit may be a capacitor.At least one internal component of the module may be a power management unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The present invention will now be described by way of example with reference to the accompanying drawings. In the drawings:

[0057] Figure 1 A first example of a card architecture is shown.

[0058] Figure 2 A second example of a card architecture is shown, where the module is connected to the card antenna.

[0059] Figure 3 A third example of a card architecture is shown, where the module and the embedded chip are connected to the card antenna.

[0060] Figure 4 Shows the use of Figure 3 An example implementation of a card of the illustrated card architecture.

[0061] Figure 5 An example of a module including a power regulation circuit is shown.

[0062] Figure 6 An example of a power regulation circuit is shown.

[0063] Figure 7 A first example of a noise mitigation circuit for reducing noise feedback to a card reader is shown.

[0064] Fig. 8A and Figure 8B A second example of a noise mitigation circuit for reducing noise feedback to a card reader is shown.

[0065] Fig. 9 A third example of a noise mitigation circuit for reducing noise feedback to a card reader is shown.

[0066] Fig.10A fourth example of a noise mitigation circuit for reducing noise feedback to a card reader is shown. DETAILED DESCRIPTION

[0067] The present disclosure relates to a device for contactless or contact communication with a terminal. The device includes: an antenna for receiving a wireless signal emitted by the terminal; an embedded chip (e.g., an integrated circuit chip) and an additional embedded module. The modules are separated from the chip (logically and / or physically); for example, they can be different components each embedded in the device. The chip generates data for communicating with the terminal to perform a first function associated with the device. The first function can be the basic or main function of the device. The chip may be, for example, a security element. The module is configured to perform processing as part of a second function associated with the device. Therefore, the device is a multifunctional device. The second function can be implemented by both the chip and the module; that is, the processing required to perform the second function can be distributed across both the chip and the module. Optionally, the processing required to perform the second function can be performed entirely by the module; that is, the module can perform the second function.

[0068] The device may be a smart card, and the terminal may be a card reader. In a specific embodiment, the device is a smart card, such as a bank card or a credit card, and the primary function is to perform financial transactions, such as making a purchase. The second function may be a biometric authentication. Biometric authentication may authenticate the user of the device to enable the first function (e.g., to perform a financial transaction). Alternatively, the second function may be to capture an image of a portion of the user (e.g., for the purpose of biometric authentication). Other example embodiments will be described in more detail below. The module is connected to an antenna and includes a power collection unit configured to collect power from a wireless signal received by the antenna from the terminal. This collected power is used to power at least the module within the device. In some examples, the power collected by the module is used to power both the module and the embedded chip. In other examples, the antenna is shared by both the embedded chip and the module, and each of the chip and the module includes a corresponding power collection unit to collect power from the wireless signal received by the antenna from the terminal.

[0069] Now refer to Figures 1 to 10Various internal architectures of multifunction devices are described. In each of these examples, the device is in the form of a smart card and the terminal communicating therewith is in the form of a card reader. This is for illustrative purposes only, and it should be understood that each of the following examples is implemented in any suitable device capable of performing contactless and / or contact communication with the terminal. For example, the following examples are implemented in a device that adopts a form factor other than a card, such as a fob, a dongle, or a security token (e.g., a USB token). Optionally, the following examples are implemented in the following devices: a device integrated into a communication device such as a mobile phone or smart phone; a wearable device (such as a bracelet, a watch, a glove / a pair of gloves, a pin (e.g., a brooch), a badge, or some other contactless wearable device).

[0070] Each of these figures shows a card that can communicate with a terminal by physical contact (by operating in a contact operating mode) and without direct physical contact (by operating in a contactless operating mode). These cards are called dual interface cards because they have a physical contact interface (e.g., in the form of a contact element) and a contactless interface (e.g., in the form of a contactless front end). These cards can be configured to communicate with the terminal according to any suitable radio communication standard when operating in contactless mode, such as near field communication (NFC). In each figure, the card includes: an embedded chip for performing a first function associated with the card; and a separate module that operates to perform a process that is part of a second function associated with the card. The second function can be performed entirely by the module, or both the chip and the module can perform portions of the processing to perform the second function.

[0071] The architecture illustrated in these figures can be implemented in a card incorporating a variety of different functions. For example, the chip can implement banking functionality. Alternatively, the chip can be operated to provide some other function associated with a card that requires communication with a terminal, such as: providing the card user with physical access to an environmental area (e.g., building access); identifying or authenticating the user; retrieving personal user information (e.g., medical information and records), etc. The chip can be configured to operate in accordance with the ISO14443 standard (when operating in contactless mode) and the ISO7816 standard as well as The module may provide some other functionality associated with a card that does not require communication with a card reader. For example, the module may be a biometric sensor module that includes one or more biometric sensors. The biometric sensor module may be operable to perform biometric identification or authentication of one or more biometric parameters, including, for example: fingerprint recognition; iris recognition; vein recognition; retinal recognition; voice recognition; behavior recognition; facial recognition, etc. Alternatively, the module may be a PIN or password generator, a movement or position sensor, a display screen, a status indicator, or a data input mechanism such as a keyboard.

[0072] Figure 1 An example card 100 is shown having an internal architecture of a first type. The card includes an antenna 104, a chip 106, a module 108, and a contact element 118. In general, the card may include one or more contact elements; a single contact element is shown here for clarity.

[0073] The chip is embedded in the card and may be, for example, a security element. Module 108 may also be embedded in the card. A module is a component physically and / or logically different from chip 106. Each of chip 106 and module 108 may, for example, be implemented on a corresponding integrated circuit chip embedded in the card. Module 108 and chip 106 are connected to each other via a link 110 such as a bus.

[0074] The contact element 118 is connected to the chip 106. The chip can be connected to the contact element by a conductive link. The contact element enables the card to communicate with the card reader by direct physical contact. When the card and the reader are brought into appropriate physical contact, the contact element provides an electrical connection to the card reader. Therefore, when the card is operating in contact mode, the chip receives power from the card reader through the contact element. When operating in contact mode, the card can communicate with the card reader in accordance with the ISO7816 standard.

[0075] The chip includes a contact modem 120 that manages the transmission and reception of messages to and from the card reader when operating in contact mode. The contact modem 120 may also ensure that communications between the chip and the card reader when the card is operating in contact mode meet any relevant standards (eg ISO 7816).

[0076] The antenna 104 is connected to the chip 106. The antenna is not connected to the module 108. The chip includes a power collection unit 112 that collects power from a signal emitted by the card reader and received by the antenna 104 when the card is operating in contactless mode. The power collection unit 112 can, for example, induce a voltage from the received signal. This induced voltage can be supplied to the chip 106 and other components of the module 108. The chip also includes a receiver / transmitter (Rx / Tx) modem 114 that manages the transmission of messages to the card reader and the reception of messages from the card reader when in contactless mode. If the communication between the card 100 and the card reader 102 is subject to one or more standards, the transceiver modem 114 can operate to manage the reception and transmission of those messages to comply with the standards.

[0077] exist Figure 1 In the illustrated architecture, only the chip 106 is connected to the antenna 104, and therefore only the chip 106 harvests power from the signal received from the card reader. Power-up, subsequent power consumption of the module 108 during operation, and power-down are therefore controlled by the chip 106. The transfer of harvested power to the module 108 can be controlled by the power management unit 116 of the chip 106.

[0078] Already realized, Figure 1 A problem with the architecture shown is that the module 108 is not easily able to control or manage the amount of power it receives, as this is controlled independently of the module by the chip 106. However, in order to be able to efficiently manage power to the module, it may be desirable to have detailed knowledge of: (i) the timing and power requirements of the module; (ii) the stage or level of processing at the module; and (iii) knowledge of the available power within the magnetic field emitted by the reader. It is therefore likely to be challenging to achieve effective power management of the module from the chip, particularly if the module and chip are supplied from different suppliers. Figure 1 Another problem with the architecture shown is that it may require modifications to the chip to power the module. Such modifications to the chip can be expensive and time-consuming, especially if the chip is configured to comply with industry regulations and standards with strict safety requirements (such as ISO ISO14443, ISO7816 and standard).

[0079] Figure 2 An alternative architecture within a multifunction card is illustrated.

[0080] Card 200 includes antenna 204, embedded chip 206, module 208 and contact element 220. Module 208 can be embedded in the body of card 200. Module 208 is also a component different from chip 206 (i.e., the module is logically and / or physically separated from the chip). Module 208 can, for example, be implemented in an integrated circuit chip separated from chip 206. Module 208 and chip 206 are connected to each other via link 210. For example, link 210 may be a bus.

[0081] The contact element 220 is connected to the chip 206. The chip can be connected to the contact element by a conductive link. The contact element enables the card to communicate with the card reader 202 by direct physical contact. When the card and the reader are in suitable physical contact, the contact element provides an electrical connection to the card reader. Therefore, when the card is operating in contact mode, the chip receives power from the card reader through the contact element. When operating in contact mode, the card can communicate with the card reader in accordance with the ISO7816 standard. The power provided from the reader in contact mode can be provided to the module 208 to power its internal components. The power supply from the chip to the module in contact mode can be controlled by the power management unit 218 in the chip.

[0082] The chip may include a contact modem 222 that manages the transmission and reception of messages to and from the card reader when operating in contact mode. The contact modem 222 may also ensure that communications between the chip and the card reader meet any relevant standards (e.g., ISO 7816) when the card is operating in contact mode.

[0083] When operating in contactless mode, card 200 communicates with (eg, sends messages to and / or receives messages from) card reader 202 via antenna 204 .

[0084] exist Figure 2 In the illustrated architecture, only the module 208 is connected to the antenna 204; the chip 206 is not connected to the antenna. The module 208 includes a power harvesting unit 212 configured to harvest power from a signal received by the antenna 204 from the reader 202 when operating in the contactless mode. Figure 1In contrast to the illustrated architecture, chip 206 does not include a power collection unit because chip 206 is not connected to antenna 204 and is therefore not able to collect power from the received signal. The power collected by power collection unit 212 can be provided to other components of module 208. The power collected by power collection unit 212 can also be provided to chip 206. Module 208 can supply power to chip 206 to enable the chip to perform its functions. This power can be provided by link 210 or by another link (not shown). The transmission of the collected power to chip 206 can be controlled by power management unit 216 of module 208.

[0085] Because only module 208 is connected to antenna 204, when the card is operating in contactless mode, communication with the card reader 202 is performed by module 208. That is, module 208 controls and manages the transmission of messages to and from the card reader 202 in contactless mode. Control of messages to and from the card reader 202 is controlled by the Rx / Tx modem 214 within module 208. As described above, the communication between the card 200 and the card reader 202 may be subject to one or more standards. In such cases, the transceiver modem 214 can control the message exchange with the card reader to comply with the one or more standards. For example, these standards may specify a time window for the transmission and / or reception of messages; a format for messages; or an anti-collision and / or transmission protocol.

[0086] The data included in the message to be sent to the card reader 202 in contactless mode can be generated by the chip 206 during its operation. Similarly, the data included in the message received by the module 208 can be routed to the chip 206 (e.g., via the link 210). In other words, the chip 206 and the card reader 202 can transmit or exchange messages via the module 208 in contactless mode. Although the transceiver modem 214 that manages the communication with the card reader is located within the module 208, the module 208 itself may not generate the data or message transmitted to the card reader 202. That is, only the chip 206 can generate the data transmitted to the card reader. In this regard, the chip 206 can be referred to as a communication master because it is the only component of the card that communicates with the card reader (i.e., the only component that processes the message received from the card reader 202 and / or generates the message content for transmission to the reader). In some examples, the message containing data transmitted to the card reader 202 can also be generated only by the chip 206. The module 208 (eg, the transceiver modem 214 within the module) then operates to modulate the messages onto the signals emitted by the card reader to transmit those messages to the card reader.

[0087] exist Figure 3 Another example architecture is illustrated in .

[0088] Figure 3 A card 300 is shown. The card 300 includes an antenna 304, an embedded chip 306, a module 308, and a contact element 324. The module 308 is logically and / or physically separate from the chip 306. In the example shown, the module is a different component from the chip 306 connected by a link 310, which can be, for example, a bus. The module 308 can be implemented in an integrated circuit chip (ICC) separate from the chip 306. In other examples, the module and the chip can be integrated on a single ICC, but are logically separate. The card 300 communicates with the reader 302 (e.g., sends messages to the reader and / or receives messages from the reader) via the antenna 304 when operating in a contactless mode, and communicates with the reader 302 via the contact element 324 when operating in a contact mode. In general, a card can include one or more contact elements; one contact element is shown here for clarity.

[0089] Contact element 324 is connected to chip 306 and module 308, for example, by a conductive link. The contact element enables the card to communicate with the card reader by direct physical contact. When the card and the reader are in suitable physical contact, the contact element provides an electrical connection to the card reader. Therefore, when the card is operating in contact mode, chip 306 and module 308 receive power from the card reader through the contact element. The power provided from the reader in contact mode can be provided to the module and chip to power its internal components.

[0090] Antenna 304 is connected to both chip 306 and module 308. Antenna is shown connected to chip 306 and module 308 via power line 312, which is routed from the antenna to both the chip and module. Power line 312 may be a physical line, such as a conductive element.

[0091] Chip 306 includes a power harvesting unit 314. The power harvesting unit is operable to harvest power from signals received by antenna 304 when the card is operating in contactless mode. The power harvested by unit 314 may be provided to other components of chip 306 to power those components.

[0092] Chip 306 also includes a power management unit (PMU) 318. PMU 318 operates to manage or control the use of power (collected by power collection unit 314 in contactless mode or provided by contact element 324 in contact mode) by components of the chip. PMU 318 can control the power consumed by other components of the chip to perform their tasks.

[0093] Module 308 includes its own power collection unit 316. Power collection unit 316 is operable to collect power from signals received by antenna 304 in contactless mode. Power collected by unit 316 can be provided to other components of module 308 to power those components. The presence of power collection unit 316 within module 308 enables the module to collect power from signals received from reader 302 separately from chip 306.

[0094] Module 308 also includes its own power management unit 320 to manage or control the consumption of power by the components of the module (collected by power collection unit 316 in contactless mode or supplied through contact element 324 in contact mode). PMU 320 can control the power consumed by other components of module 308 to perform their tasks during their operation.

[0095] Because contact element 324 is connected to both chip 306 and module 308, and antenna 304 is also connected to both chip 306 and module 308, both chip and module can receive or collect power from reader separately from each other. However, only chip 306 can communicate with reader. That is, only chip 306 can generate a message and send it to reader (for example, by load modulating the signal sent by reader). Similarly, chip 306 is the only component that can receive and process the message transmitted from reader (for example, by demodulating the signal received by antenna) on card 300. In other words, only chip 306 generates data transmitted to reader 302. Therefore, although module 308 can generate data and transmit it to chip 306 in some examples, module 308 does not (directly or indirectly) communicate with reader 302. In other words, the data generated by module 308 can remain locally located on card 300.

[0096] Control of messages to and from the card reader 302 (more specifically, between the chip 306 and the reader 302) is performed by an Rx / Tx transceiver modem 322 and a contact modem 326 within the chip 306. The transceiver modem 322 controls message communications with the reader 302 in contactless mode, while the contact modem 326 controls message communications with the reader 302 in contact mode.

[0097] The transceiver modem 322 may, for example, control the exchange of messages with the card reader 302 to comply with one or more standards governing communication between the card 300 and the reader 302 (e.g., ISO 14443, ISO 7816, and Standards). For example, these standards may specify time windows for transmission and / or reception of messages; formats for messages; or anti-collision and / or transmission protocols. Transceiver modem 322 may also be responsible for modulating the message payload generated by chip 306 onto signals emitted by reader 302 to transmit those messages to the reader, and demodulating signals received by antenna 304 to decode messages received from the reader.

[0098] The contact modem 326 may similarly control the message exchange with the card reader 302 to comply with standards governing communication between a card and a reader in contact mode (e.g., ISO 7816 and standard).

[0099] Figure 3 The illustrated architecture can conveniently present advantages over Figure 1 Several advantages of the illustrated architecture.

[0100] First, because the antenna 304 is shared by both the chip 306 and the module 308, and both the chip 306 and the module 308 include corresponding power collection units, the module 308 can collect power from the received signal independently of the chip 306 in the contactless mode, for example, independently of the operation of the chip. In addition, because the chip 306 and the module 308 include corresponding power management units, the module 308 and the chip 306 can control and manage the power consumption of the corresponding internal components independently of each other. This can enable greater control over the processing tasks and functions performed by the various components of the chip and the module, which may be particularly advantageous in embodiments when: the power collected from the card varies over the typical time required to perform those tasks and functions (for example, due to changes in the physical position of the card in space); and / or when the communication between the card and the reader is strictly regulated, such as when the card communicates with the reader to perform banking functionality, in which case the communication must particularly meet Independent control and management of the power consumption of chip 306 and module 308 also enables the chip and module (or their alternative components) to be powered down or placed in a low power mode when they are not needed, thereby eliminating the need for such independent control. Figure 1 and Figure 2 The power savings achieved by the illustrated architecture result in greater power savings in comparison.

[0101] Second, enabling both chip 306 and module 308 to access and collect power from the antenna independently of each other reduces the complexity of controlling the power management of both components. As described above, effective power management of module 308 may require knowledge of parameters including the timing and power requirements of the module, knowledge of available power that can be collected from signals emitted by the reader, and knowledge of various stages or levels of processing of the module. That is, effective power management of module 308 may require local knowledge of the module and its operation. Therefore, enabling module 308 to manage its power independently of chip 306 thus simplifies the implementation of the module's effective power management strategy.

[0102] Third, connecting module 308 to antenna 304 enables the module to harvest power from received signals without input or control from chip 306, meaning that the basic operation of the chip can remain unchanged compared to the situation where module 308 is not present on the card. This is convenient because in certain embodiments where communication between the chip and the reader is strictly regulated, modification of the connection or operation of the chip (e.g., by enabling access to the chip from another component) may be restricted or technically complex to implement. Figure 3 The illustrated architecture may enable a card including a chip implementing a basic or primary functionality to be more easily adapted to include an additional module implementing a secondary or additional functionality, since substantial modification of the chip may be avoided.

[0103] Figure 3 The illustrated architecture can also provide advantages over Figure 2 Advantages of the illustrated architecture.

[0104] Figure 3 The illustrated architecture enables the Rx / Tx modem to remain within chip 306. This is particularly convenient because including the Rx / Tx modem within a module (as in card 200) can present several challenges. For example:

[0105] (i) Including an Rx / Tx modem within the module may enable the module to manipulate the communication between the card and the reader, or introduce interference to otherwise manipulate the results of the primary function of the card, thereby raising security concerns. Therefore, when the card and reader are configured to comply with a communication protocol with relatively strict security requirements (e.g. ), implementing the Rx / Tx modem within an external module will likely impose additional safety requirements on the module that might otherwise be needed.

[0106] (ii) Communication between the chip and the reader will require sending messages over the link 210, which may consume additional power, bandwidth and introduce additional latency.

[0107] (iii) The Rx / Tx modem is a relatively complex component that may require expertise to implement effectively (especially when compliance with ISO14443, ISO7816 and Including the Rx / Tx modem within the module increases its complexity, which may be of practical significance when the chips and modules are supplied by different suppliers.

[0108] and Figure 2 Compared to the architecture shown, Figure 3 The architecture is also more compatible with contact operation mode. Figure 2 In the architecture shown, the modem for contact mode communication is located within chip 206, whereas the modem for contactless mode communication is located within module 208. The result of this is that the communication paths for messages exchanged between the card and the reader are different for the two operating modes, which may, for example, lead to more complex routing strategies. Figure 3 In the architecture shown, both the transceiver modem 322 and the contact modem 326 are located within the chip 306, which means that the communication path for messages exchanged with the card reader is the same for both contact and contactless modes.

[0109] It should be recognized that Figure 1-3 The card illustrated in the figure may include additional components not shown in the figure. For example, both the chip and the module may include a dedicated microcontroller unit (MCU).

[0110] Figure 4 Shows the use of Figure 3 A more specific implementation of a card having the architecture illustrated in FIG.

[0111] Figure 4 Card 400 is shown. Card 400 includes antenna 404, embedded chip in the form of security element 406 and module in the form of biometric sensor module 408. When the card is operated in contactless mode, when the card is close enough to the reader, antenna 404 receives the wireless signal sent by reader 402. In this particular example, the signal sent by the reader is an NFC signal. Therefore, the card and reader communicate according to the NFC radio communication standard. The contactless communication between card 400 and reader 402 can also comply with ISO / IEC 14443 standard and ISO / IEC 7816 standard. In this respect, reader 402 can be referred to as a proximity coupling device (PCD), and card 400 can be referred to as a proximity integrated circuit card (PICC).

[0112] Safety element 406 and sensor module 408 are logically and / or physically separated components of card 400. If physically separated, then they may not be implemented on a common chip, but are alternatively implemented on the separate corresponding chips embedded in the card separately. If only logically separated, then they can be implemented on a common chip. In the example shown here, they are physically separated.

[0113] The security element 406 and the sensor module 408 are interconnected via a link 430. The link 430 may be a bus, such as an inter-integrated circuit (IC) 2 C) bus.

[0114] Antenna 404 is shared between security element 406 and biometric sensor module 408. That is, both the security element and the biometric sensor module are connected to the antenna. The card includes a power line 410 that is routed from the antenna to both the security element and the biometric sensor module to connect those components to the antenna. The power line can be a physical line, such as a wire.

[0115] The card 400 also includes one or more contact elements 412 to enable the card to communicate with the reader 402 through direct physical contact. When the card and the reader are brought into appropriate physical contact, the contact elements provide an electrical connection to the card reader 402. The contact communication between the card and the card reader may be governed by the ISO / IEC 7816 standard. When the card is operating in contact mode, the security element 406 and the module 408 receive power from the card reader 402 through one or more contact elements 412 on the link 434.

[0116] The safety element 406 operates to perform a first function associated with the card 400. As part of performing this function, the safety element exchanges data with the card reader. This data is exchanged through a contactless interface when the card is operating in contactless mode, and through a contact interface when the card is operating in contact mode. The safety element includes a contactless front end 414, a transceiver modem 416, a safety microcontroller unit (MCU) 418, a power management unit 432, and a contact modem 436. The components of the safety element can be interconnected by a bus.

[0117] The contactless front end 414 operates to harvest power from wireless signals emitted by the reader 402 and received by the antenna 404 when the card is operating in contactless mode. The contactless front end may operate to harvest power from the received signal and output a rectified voltage to other components within the secure element, namely, to the transceiver modem 416, the power management unit 432, and the MCU 418. The contactless front end is an example of a power harvesting unit.

[0118] The power management unit 432 manages or controls the power supplied to the components of the secure element, which is collected by the contactless front end or provided through the contact element 412. In this way, the power management unit 432 can control the power consumed by other components of the secure element. The power management unit 432 can be physically interconnected to each of the following items: the contactless front end 414; the modems 416 and 436; and the MCU 418.

[0119] The transceiver modem 416 operates to extract data from the received wireless signal when the card is operating in contactless mode. The reader 402 transfers data to the card 400 by modulating the signal it generates. The reader can modulate the generated signal by means of amplitude modulation. The modem can then extract data from the received wireless signal by demodulating the amplitude changes of the voltage induced in the antenna caused by the amplitude modulation at the reader 402.

[0120] Modem 416 can also be operated to transfer data and messages from the security element to the card reader 402 when the card is operating in contactless mode. The modem can transfer messages to the reader by modulating the data generated in the security element onto the wireless signal emitted from the reader. To do this, modem 416 applies a modulated load to antenna 404. Modulating the antenna load at the card 400 changes the power drawn from the received signal according to the modulation. The change in the drawn power can be detected by the reader 402 and interpreted as data transmitted from the card. This process can be called load modulation.

[0121] The modem 416 may also be responsible for controlling the transmission of messages from the secure element to the reader to comply with the ISO / IEC 14443 and ISO / IEC 7816 standards. The modem 416 is thus an example of a transmission management unit.

[0122] The contact mode modem 436 operates to transfer and receive data and messages from the secure element to the card reader 402 when the card is operating in contact mode. The contact mode modem can exchange messages with the card reader 402 via the contact element 412. The contact mode modem can control the transmission of messages from the secure element to the reader to comply with the ISO / IEC 7816 standard.

[0123] MCU 418 can be operated to store data (e.g., data received from reader 402 and / or data generated within the secure element or received from sensor module 408). MCU can also be operated to perform one or more tasks (e.g., encryption and / or authentication) to implement the first function and / or the second function associated with the card.

[0124] Biometric sensor module 408 operates to perform processes that are part of a second function associated with the card. In this example, the function is to perform biometric identification or authentication of the user of card 400. In some examples, module 408 performs all processes that form a biometric authentication; that is, module 408 performs biometric authentication. In other examples, the processes required to perform biometric authentication are distributed between module 408 and chip 406; that is, both the chip and the security element perform the processes required to perform biometric authentication. Examples of this will be described in more detail below.

[0125] In contrast to secure element 406, biometric sensor module does not exchange data with a card reader. Sensor module 408 includes contactless front end 420; power management unit 422; microcontroller unit (MCU) 424; biometric sensor 426 and application specific integrated circuit (ASIC) 428. The components of sensor module 408 may be interconnected by a bus.

[0126] The contactless front end 420 operates in a similar manner to the front end 414 and harvests power from wireless signals emitted from the card reader and received by the antenna 404 when the card is operating in contactless mode. Because both the secure element 406 and the biometric sensor module 408 are connected to the antenna and include their own contactless front ends, the biometric sensor module 408 is able to harvest power from the wireless signals received at the antenna independently of the secure element 406.

[0127] The contactless front end 420 outputs the collected power to other components of the biometric sensor module 408. The contactless front end can be operated to output a rectified voltage from the power collected from the received signal. The rectified voltage can be supplied to other internal components of the sensor module 408. In a specific arrangement, the contactless front end outputs the rectified voltage to a power management unit 422. The power management unit can be the only component of the biometric sensor module 408 that receives power from the contactless front end 420 in the contactless mode.

[0128] The power management unit 422 manages or controls the power supplied to the components of the biometric sensor module 408. In this way, the power management unit 422 can control the power consumed by other components of the sensor module. When the card is operating in contactless mode, the power management unit 422 receives the collected power from the contactless front end 420. When the card is operating in contact mode, the power management unit 422 receives the power provided from the card reader 402 through the contact element 412. Therefore, the power management unit can be connected to the contact element (e.g., through a conductive link).

[0129] The power management unit 422 can be physically interconnected to each of the MCU 424, the sensor 426, and the ASIC 428. This allows the power management unit to separately control the power supplied to each of these components. Including the power management unit 422 within the sensor module 408 also enables the sensor module to control the power consumption of each component within it independently of the security element 406.

[0130] Sensor 426 is a biometric sensor for capturing an image of a biometric source. For example, sensor 426 may be a fingerprint sensor, a retina sensor, an iris sensor, a facial sensor, etc.

[0131] ASIC 428 controls the operation of sensor 426. The ASIC may, for example, instruct the sensor to enter an acquisition mode in which the sensor captures an image of a biometric source (e.g., fingerprint, retina, iris, etc.). The ASIC may also receive image data captured by sensor 426 (e.g., during acquisition mode). The ASIC may transmit the captured image data to MCU 424. After capturing an image, the ASIC may also instruct the sensor to power down to a standby mode.

[0132] MCU 424 can perform image matching to compare the image captured by sensor 426 with a stored template image or with a stored template image. The template image is a credible image. The image can be credible in the sense that it is regarded as an image of a biometric source belonging to the user of card 400. In order to perform image matching, the MCU can perform feature extraction on the captured image to identify a set of one or more extracted features. The extracted features are then compared with the features of the template image to determine whether the captured image matches the template image. The MCU can, for example, compare the features of the image to determine the matcher score of the captured image. If the matcher score is above a predetermined threshold, the captured image can be considered to match the template image.

[0133] MCU can transmit the indication that the captured image matches the template image to security element 406. Security element 406 can then transmit the indication that the user of the card has been authenticated back to reader 402. Authentication of the card user can enable the primary function associated with card 400 to be completed. Alternatively, MCU can transmit to security element 406 that the captured image does not match the template image, in which case the user of the card has not been authenticated and the primary function associated with card 400 may not proceed, or may proceed in a modified manner due to the absence of a match. This is an example of an embodiment in which each stage or process of biometric authentication is performed by module 408.

[0134] In an alternative embodiment, the process of performing image matching may be performed by MCU 418 within secure element 406, rather than by MCU 424. This is an example of an embodiment in which the process of biometric authentication is performed by both secure element 406 and module 408; i.e., biometric authentication is not performed solely by module 408.

[0135] Figure 5 Another example of a module is shown. Module 508 is shown connected to antenna 504 and contact element 512. For the sake of clarity, chips (such as security elements) have been omitted. Figure 3 or Figure 4 Module 508 is implemented within the illustrated architecture.

[0136] Module 508 includes a contactless front end (CLF) 520, a power management unit 522, an MCU 524, a sensor 526, and an ASIC 528. These components can be used in conjunction with Figure 4 Module 508 also includes contact power conditioning circuit 530. The power conditioning circuit is connected to contact element 512 via link 532. Link 532 may be a conductive link.

[0137] The power regulation circuit 530 performs two functions. First, it is operable to prevent inrush current from overloading the card reader when the card is operating in contact mode. Inrush current refers to the current drawn by the card when the components of the card are powered on, such as when the card is inserted into the card reader in contact mode. Conventional card readers are typically designed to power only the security elements on the card, rather than the security elements plus additional modules. As a result, if the amount of current drawn at power-on exceeds a predetermined threshold, the card reader can detect a fault. It has been recognized that including a module in the card increases the current drawn at power-on to power the internal components of the module, thereby increasing the risk that the current drawn will overload the card reader, causing a fault to occur. The power regulation circuit operates to limit the current drawn by the module through the contact elements during power-on when the card is operating in contact mode. This will be described in more detail below.

[0138] Secondly, the power conditioning circuit operates to isolate the contact elements from power harvested in the module during contactless operation. It has been recognized that when the module uses its contactless front end to harvest power from the signal emitted by the card reader, this harvested power can additionally power the contact elements, causing the security element to falsely detect that the card is operating in its contact mode of operation.

[0139] exist Figure 6An example power regulation circuit is shown in . The power regulation circuit is generally indicated at 600 and is shown connected to contact elements 512 and a contactless front end (CLF) 520 of the module. The circuit is also coupled to an internal component of the module, which in this example is a power management unit 522 of the module.

[0140] The circuit includes a through path 602, which includes a first path 604 and a second path 606 interconnected by a switch element 608. The switch element 608 is a bipolar transistor. In particular, in this example, the switch element 608 is a PNP transistor including an emitter, a base and a collector. The emitter is electrically connected to the first path 604, and the collector is electrically connected to the second path 606. The through path 602 extends between the contact element 512 and the contactless front end 520. Therefore, the first path 604 extends between the contact element 512 and the switch element 608, and the second path extends between the switch element 608 and the contactless front end 520. In the current example where the switch element is a PNP transistor, the first path extends between the contact element 512 and the emitter of the PNP transistor, and the second path extends between the collector of the PNP transistor and the contactless front end 520.

[0141] The circuit also includes a bypass route 610 arranged in parallel with the switch element 608. The bypass route is therefore connected to the first path 604 and the second path 606. The bypass route 610 includes a resistor 612 and a diode 614 in this example. In other examples, it can include multiple resistors arranged in series. The diode 614 has a forward direction from the contact element 512 to the contactless front end 520 (and therefore has a reverse direction from the contactless front end to the contact element). The bypass route allows current to flow from the first path to the second path without passing through the switch element 608 (i.e., through the bypass switch element 608).

[0142] The circuit also includes a coupling unit 616 that couples the first path 604 to the base of the switching element. The coupling unit has a first terminal connected to the first path 604 and a second terminal coupled to the base of the switching element 608 and coupled to ground via a resistor 618. The coupling unit 616 is therefore located on the contact element side of the bypass route 610 and the switching element 608. In this example, the coupling unit is a capacitor. The coupling unit operates to pass a time-varying current supplied from the contact element.

[0143] The circuit further comprises a resistor 620 arranged between the first path 604 and ground. The resistor 620 is arranged on the contact element side of the capacitor 616.

[0144] On the CLF side of the switch element 608, a resistor 622 and a capacitor 624 are provided. A first terminal of the capacitor 624 is coupled to the second path 606, and a second terminal of the capacitor is connected to ground. The resistor 622 is located between the output of the diode 614 and the first terminal of the capacitor 624. As will be described in more detail below, the resistors 612, 622 and the capacitor 624 form a low pass filter 626. In the current example where the switch element 608 is a PNP transistor, it can also be said that the resistor 622 is located between the collector of the PNP transistor 608 and the first terminal of the capacitor 624.

[0145] Note that circuit 600 includes only a single switching element.

[0146] Circuit 600 can operate in forward mode and reverse mode. When operating in forward mode, the circuit controls the current flow from contact element 512 to PMU 522 of the module during power-up and after power-up. In other words, the circuit controls the amount of current drawn from the contact element by PMU 522. The circuit operates in forward mode to prevent surge current from overloading the card reader when the card is operating in contact mode. When operating in reverse mode, the circuit controls or isolates the current flow from CLF 520 back to contact element 512 when the card is operating in contactless mode. In other words, the circuit operates in reverse mode to isolate the contact element from the power collected by the contactless front end of the module. These operating modes will now be described in more detail.

[0147] When the card is operating in contact mode, then during power up (e.g., when the card is inserted into the card reader), power is supplied from the card reader through the contact element (e.g., in accordance with the ISO 7816 standard). This initial supply of power pulls the first path 604 high. The coupling capacitor 616 couples the supplied power to the base of the switching element 608, thereby pulling the base high and causing the switching element 608 to open. By driving the switching element open, power can then only be transferred from the first circuit path 604 to the second circuit path 606 during power up through the bypass circuit 610; in other words, the bypass circuit forms the only path between the first circuit path 604 and the second circuit path 606.

[0148] As described above, resistors 612, 622 and capacitor 624 form a low pass RC filter network. Bypass circuit 610 thus forms part of the low pass RC filter network. Thus, by driving switch element 608 open, the current supplied from the contact element flows through bypass circuit 610 and the low pass filter network. The low pass filter network operates to slow down the inrush current during power up, thereby reducing the peak inrush current value. Thus, circuit 600 controls the current drawn from the contact element by PMU 552 to prevent the inrush current from overloading the card reader. The amount of current drawn by the PMU during power up can be controlled by appropriate resistance selection of resistors 612 and 622 and capacitor 624.

[0149] In time, coupling capacitor 616 is charged by contact element 512, causing the base of switch element 608 to be pulled low by resistor 618. Thus, after power is applied, switch element 608 is pulled closed by resistor 618, thereby supplying current from contact element 512 from first circuit path 604 to second circuit path 606 (and therefore to PMU 522) through switch element 608.

[0150] The reverse mode of operation (when the card is operating in contactless mode) will now be described.

[0151] As described above, when the card is operating in contactless mode, the contactless front end 520 of the module operates to collect power from the signal emitted by the self-card reader. When the card is operating in contactless mode, power is not drawn through the contact element 512. The switch element 608 is therefore disconnected because its base is not negatively biased relative to the emitter. The switch element 608 and the bypass circuit 610 therefore prevent current from flowing from the second circuit path 606 to the first circuit path 604. In other words, during the contactless operating mode, the power collected from the CLF 520 is isolated from the contact element 512 by: (i) an open circuit switch element; and (ii) a bypass circuit whose diode 614 prevents current from flowing from the second circuit path 606 to the first circuit path 604.

[0152] The arrangement of circuit 600 has several advantages.

[0153] First, the circuit 600 operates to both prevent inrush current from overloading the card reader when the card is operating in contact mode, and to isolate the contact element from the power collected by the contactless front end of the module during the contactless operation mode, yet only includes a single switching element, thereby reducing the cost and complexity of introducing power regulation circuits within the module. The circuit 600 can therefore be implemented with a reduced number of components compared to methods that implement separate circuits to perform inrush current prevention and contact element isolation. Reducing the component count can also reduce the cost of the circuit.

[0154] Secondly, efficient use of components of the power conditioning circuit means that the circuit can be implemented on a relatively small physical scale. This is convenient because packaging constraints on the card may be relatively high. For example, it may be desirable for the module to be as physically small as possible so as not to substantially increase the thickness and / or weight of the card.

[0155] Third, the use of a single switching element, which may be in the form of a PNP transistor, may facilitate the provision of a power conditioning circuit that is subject to only a relatively low voltage drop across the switching element, compared to other possible implementations (e.g., implementations that employ multiple switching elements or implementations that use only diodes to control the direction of current flow). The reduced voltage drop enables other components of the module, such as the biometric sensor, to obtain higher voltages. This may be particularly advantageous for examples where the biometric sensor is a capacitive fingerprint sensor, as the higher level of available voltage results in an improved signal-to-noise ratio and therefore better quality image capture. When the device is used for biometric authentication, the improved image capture capability may result in improved false rejection / false acceptance rates.

[0156] all in all, Figures 2 to 5 Various architectures are described in which the card antenna is connected to a module that is logically and / or physically separate from the embedded chip that exchanges data with the reader. As explained above, when the card is operating in contactless mode, data can be transmitted from the card back to the reader by load modulating the signal emitted by the reader. In effect, the data is modulated onto the signal emitted by the reader by varying the power drawn from the signal at the card. It has been recognized that additional components of the card that draw current from the emitted signal (such as Figures 2 to 4 modules in the architecture shown) will affect the load modulation of the emitted signal, which may appear as additional noise to the reader.

[0157] The introduction of additional noise at the card reader can be problematic, especially when the communication between the card and the card reader is strictly regulated to comply with industry standards.

[0158] In order to counteract the effect of the module on load modulation when the card is operated in contactless mode, the card 200, 300, 400 may additionally include a noise mitigation circuit. In summary, the noise mitigation circuit operates to store charge when the card is brought into the range of the reader. Entering the range means bringing the card close enough to the reader so that a voltage is induced by the card antenna from the signal emitted from the reader. Before drawing power from the signal received at the antenna, the subsequent current draw generated by the operation of the components within the module can then be supplied by the noise mitigation circuit first. This reduces the effect of the module on the load modulation of the emitted signal. Although the initial charging of the noise mitigation circuit can produce a load spike on the emitted signal, it has been recognized that this is generally more tolerable during the startup of the card assembly (i.e., when the card is first approached to the card reader) because the power spike generated by the power-up is expected and can be handled by the appropriate startup circuit within the card.

[0159] Figure 7 A first example of a noise mitigation circuit 700 is shown. The circuit 700 may be included in the power collection unit 212, the power collection unit 316, or the contactless front end 420, 520. For clarity, the circuit 700 has been removed from the Figure 7 The remaining components of those units are omitted.

[0160] Circuit 700 includes a first input 702 and a second input 704 from a card antenna and a first capacitor 706. Capacitor 706 is located across the two inputs 502 and 504. Capacitor 706 is a tuning capacitor that tunes the antenna (not shown) to the frequency of the signal emitted by the card reader. In some examples, the signal emitted by the card reader can be an NFC signal with a frequency of 13.56 MHz.

[0161] Circuit 700 also includes a rectifier circuit 708 and a power regulation circuit 710. The rectifier circuit is coupled to the terminals of capacitor 706. The rectifier circuit operates to rectify the voltage induced by the antenna. The power regulation circuit operates to output a stable regulated voltage. It may include a low dropout regulator.

[0162] Circuit 700 also includes a plurality of charging elements configured to store charge. In this example, the charging elements are capacitors. The circuit includes two capacitors 712 and 714. Capacitor 712 is located between the rectifier circuit and the power regulation circuit. Capacitor 714 is coupled to the output of the power regulation circuit. As the card enters the range of the card reader by the voltage induced by the antenna, capacitors 712 and 714 are charged. Capacitor 712 is charged by rectifier circuit 708, and capacitor 714 is charged by power regulation circuit 710. Capacitors 712 and 714 discharge to supply current to the components of the module (e.g., power management unit 422) in response to the current demand from those components during operation. In other words, capacitors 712 and 714 operate as energy temporary stores that are charged as the card approaches the reader and then discharged to supply the peak current demand to the components of the module. Therefore, circuit 700 operates to prevent the current demand from the components of the module from modulating the load on the signal emitted by the reader, which in turn reduces the noise level from the operation of the module at the reader. Capacitor 712 also acts as a smoothing capacitor for rectifier circuit 708. It may additionally act as a filter to filter out noise reaching the antenna.

[0163] exist Fig. 8A and Figure 8B Another example of a noise mitigation circuit is shown in .

[0164] Fig. 8A Local power supply decoupling circuits 802 and 804 are shown for the module's MCU 424 and sensor 426, respectively. The remaining components of the module connected to the MCU and sensors are omitted for clarity.

[0165] The local power decoupling circuits 802 and 804 each include a capacitor or multiple capacitors arranged in parallel. In this example, each local power decoupling circuit includes two capacitors arranged in parallel. When the card enters the range of the reader, the capacitor is charged from the voltage induced by the antenna. If the power harvesting circuit of the module includes the power regulation circuit 700, the capacitor can be charged by the power regulation circuit 710.

[0166] Subsequent current draws resulting from the operation of the MCU 424 and the sensor 426 may then be supplied first by the local power supply circuits 802 and 804. If the power harvesting circuit additionally includes the power supply regulation circuit 700, current may then be drawn from the capacitors 714 and 712 after drawing current from the local power supply circuits 802 and 804. In other words, the current drawn by the MCU 424 and the sensor 426 may be supplied in the following order: 1) initially from the local power supply circuits 802 and 804, respectively; 2) thereafter, from the capacitor 714 of the regulation circuit 700; and 3) thereafter, from the capacitor 712 of the regulation circuit 700. This sequential supply of the required current conveniently reduces load modulation on the signal emitted by the reader.

[0167] exist Figure 8B The wiring of the capacitors in the power supply circuits 802, 804 is illustrated in FIG. The interconnection circuit connecting the MCU / sensor to the power management unit 422 is shown at 806. Note that for simplicity, Figure 8B A single box representing an MCU or a sensor is illustrated in FIG. An equivalent interconnect circuit would connect both the MCU and the sensor to a power management unit.

[0168] It can be seen that the interconnection circuit defines two power rails VDD and VSS to the MCU / sensor. The power rail VSS is input into a first terminal end of the local decoupling circuit, and the power rail VDD is input into a second terminal end of the local decoupling circuit. The two power rails and the local decoupling circuit thus form a closed circuit with the MCU / sensor. This closed circuit enables the current required from the MCU / sensor to be supplied by the local power circuit while reducing the current supplied by the power management unit 414.

[0169] The capacitors of each local decoupling circuit also operate to filter the noise bands generated from the sensor / MCU.If each local decoupling circuit includes multiple capacitors arranged in parallel, each capacitor may have a different capacitance to filter out a different corresponding noise band.

[0170] Fig. 9 Another example of a noise mitigation circuit 900 is shown. The noise mitigation circuit 900 operates to maintain an approximately constant current load about the antenna. That is, the circuit operates to offset deviations in the current load seen at the antenna plane. Figure 7 Compared with the circuit shown in Figure 8, Fig. 9 The circuit shown may be better suited for more slowly varying current loads.

[0171] The circuit 900 may be included in the power collection unit 212, the power collection unit 316, or the contactless front end 420, 520. For clarity, Fig. 9The remaining components of those components are omitted.

[0172] The circuit 900 includes a first input 702 and a second input 704 from the card antenna and a Figure 7 The first capacitor 706 described above. The circuit also includes Figure 7 Rectifier circuit 708 and power regulation circuit 710 are depicted. The circuit additionally includes control circuit 902.

[0173] The control circuit 902 includes a current sensing and control block 904 and a variable load 906 (e.g., a resistor). The current sensing and control block 904 detects the current deviation required by other components of the module (e.g., the power management unit 422). Block 904 then controls the current supplied from the power regulation circuit 710 and capacitor 714 based on the measured deviation in the required current. Block 904 is accomplished by appropriately controlling the resistance of the variable load 906. Thus, the circuit 900 supplies a variable current level to the other components of the module in response to the deviation in the required current so as to present a constant current demand to the antenna. This reduces the noise level fed back to the reader.

[0174] Fig.10 Another example of a noise mitigation circuit 1000 implemented as part of an alternative power management architecture is shown. In this example, Figure 7 and Fig. 9 The power regulation block 710 is shown replaced by first and second types of voltage regulators, each connected to a respective component of the module (which is considered module 408 for purposes of illustration). The circuit includes a first branch and a second branch, each connected to a common node coupled to the rectifier circuit 708. The first branch includes a first type of voltage regulator coupled to a first component of the module, and the second branch includes a second type of voltage regulator coupled to a second component of the module. In this example, the first type of voltage regulator is a low dropout regulator (LDO) 1002, and the second type of voltage regulator is a switch mode power supply (SMPS) 1004. The LDO 1002 is coupled to the ASIC 428 of the module, and the SMPS 1004 is coupled to the MCU 424 of the module.

[0175] The circuit 1000 also includes a first charging element 1006 located between the LDO 1002 and the ASIC 428, and a second charging element 1008 located between the SMPS 1004 and the MCU 424. The charging elements are capacitors in this example.

[0176] The two voltage regulators 1002 and 1004 operate to output different regulated voltage levels from each other. In one particular embodiment found to be convenient for smart card applications, the voltage regulator 1002 may output a regulated voltage of approximately 2.5V, and the voltage regulator 1004 may output a regulated voltage of approximately 1.8V; that is, the first type of voltage regulator outputs a higher regulated voltage than the second type of voltage regulator. These different levels of regulated voltage enable different current levels to be provided to the two components 424 and 428. This is convenient because it has been recognized that the processing speed of the MCU 424 is a function of the supplied current. By increasing the current supplied to the MCU 424, its processing speed can be increased. A numerical illustration of how the circuit 1000 achieves this will now be described.

[0177] Equal wattage is provided to both branches of the circuit from the rectifier circuit 708. As mentioned, the LDO 1002 regulates the voltage to 2.5V in this example. For the purpose of illustration, a typical example of current is considered to be 10mA in this case. This gives a value of 25mW provided by the LDO 1002. The SMPS 1004 is known to have a typical efficiency rating of about 90% compared to the LDO. Therefore, the wattage provided to the MCU 424 (assuming that equal wattage is provided to both the LDO 1002 and the SMPS 1004 from the rectifier circuit) is equal to 25mW×90%=22.5mW. If the SMPS regulates the output voltage to 1.8V, this gives a current value of 12.5mA along the second branch. That is, the current along the second branch of the circuit 1000 is higher than the current along the first branch of the circuit 1000 due to the lower regulation voltage.

[0178] Calculations performed by the inventors have found that for a supply current of 10 mA, the MCU 424 can operate at a clock speed of approximately 60 MHz. However, for a supply current of 12.5 mA, the MCU 424 can operate at a clock speed of approximately 75 MHz, which will result in a reduction in execution time of approximately 20%.

[0179] Therefore, with Figure 7 Compared with the circuit 700, Fig.10 The circuit enables the current supplied to the MCU 424 to be increased (and correspondingly the processing speed to be increased) while still enabling the module's ASIC 428 to receive a higher output regulated voltage from the LDO 1002 (which may be required to maintain optimal performance of the ASIC).

[0180] Examples are described herein in which the device is a smart card. It should be understood that the term "card" does not imply any constraints on its size, shape, thickness or function. The card described herein may be, for example, a plastic card, such as a bank card or an ID card. It should also be understood that each of the examples described herein may be implemented in a device that adopts a different form factor other than a card, such as a snap, a dongle, or a security token (e.g., a USB token). Optionally, the device described herein may be integrated into the following devices: a communication device such as a mobile phone or a smart phone; a wearable device such as a bracelet, a watch, a glove / a pair of gloves, a pin (e.g., a brooch), a badge, or some other contactless wearable device.

[0181] Some of the cards described herein have been referred to as contactless cards. It should be understood that, as described herein, a contactless card refers to a card that can communicate with a reader via a contactless interface. However, each card described as a contactless card may also be capable of communicating with a terminal via direct physical contact. Therefore, the term "contactless" is not used herein to exclude the possibility of contact functionality.

[0182] In the examples given above, the term power may be understood to refer to any relevant characteristic of energy availability. Examples include available energy, voltage, current and power or any combination thereof.

[0183] The applicant hereby discloses separately each individual feature described herein and any combination of two or more such features, so that these features or combinations can be performed based on this specification in view of the common general knowledge of those skilled in the art in general, regardless of whether these features or combinations of features solve any problems disclosed herein, and are not limited to the scope of the claims. The applicant indicates that various aspects of the present invention can be composed of any such individual features or combinations of features. In view of the foregoing description, it is obvious to those skilled in the art that various modifications can be made within the scope of the present invention.

Claims

1. A device for contactless communication with a terminal, the device comprising: An antenna, used to receive a wireless signal sent by the terminal; an embedded chip configured to generate data for communicating with the terminal to perform a first function associated with the device, and including a first power management unit configured to control use and consumption of power by the embedded chip; as well as a module separate from the chip, configured to perform processing as part of a second function associated with the device, the module connected to the antenna and comprising a power collection unit and a second power management unit, the power collection unit being configured to collect power from the received wireless signal to at least power the module, the second power management unit being configured to control use and consumption of power by the module, The first power management unit controls the power consumption of the embedded chip and the second power management unit controls the power consumption of the module independently of each other.

2. The device according to claim 1, wherein: The chip is connected to the antenna and includes a power collection unit configured to collect power from the received wireless signal to power the chip, wherein the power collection unit of the chip is separate from the power collection unit of the module.

3. The device according to claim 2, wherein: The module is configured to harvest power from received wireless signals independently of the chip.

4. The device according to claim 2, wherein: The device is configured such that only the chip is arranged to manage message transmission and reception with the terminal.

5. The device according to claim 2, wherein: The device is configured such that only the chip is adapted to communicate messages with the terminal via the antenna.

6. The device according to any one of claims 1 to 5, wherein: The device is used for contact and contactless communication with the terminal, and further includes: One or more contact elements are connected to the embedded chip and the module and are arranged to supply power from the terminal to the embedded chip and the module when the device is in contact communication with the terminal.

7. The device according to claim 6, wherein: The module includes a power conditioning circuit coupled to the one or more contact elements, the power harvesting unit, and at least one other internal component of the module; The power regulation circuit comprises: a circuit path coupled at a first end to the one or more contact elements and at a second end to the power harvesting unit and the at least one other internal component of the module; a switching element interconnecting a first portion of the circuit path including the first end and a second portion of the circuit path including the second end, the switching element having an emitter electrically connected to the first portion of the circuit path and a collector electrically connected to the second portion of the circuit path; a bypass circuit providing a path around the switching element, the bypass circuit allowing current to flow through the bypass circuit in a direction from the first end to the second end of the circuit path; and a coupling unit including a first terminal coupled to the first portion of the circuit path and a second terminal coupled to a base of the switching element and to ground via a resistor; The power regulation circuit is arranged so that: when the device is in contact communication with the terminal, the power provided by the contact element drives the switching element to an open circuit configuration via the coupling unit, thereby limiting the current to flow from the first end of the circuit path to the second end of the circuit path through the bypass circuit; and when the device is in contactless communication with the terminal, the power collected by the power collection unit causes the switching element to adopt an open circuit configuration, thereby preventing current from flowing from the second end of the power regulation circuit to the first end of the power regulation circuit.

8. The device according to claim 7, wherein: The bypass circuit includes a diode that limits current flow in a direction only from the first portion of the circuit path to the second portion of the circuit path.

9. The device according to claim 7, wherein: The power conditioning circuit includes only a single switching element.

10. The device according to claim 7, wherein: The switching element is a bipolar transistor.

11. The device according to claim 10, wherein: The bipolar transistor is a PNP-transistor, the emitter of the transistor being electrically connected to the first portion of the circuit path and the collector being electrically connected to the second portion of the circuit path.

12. The device according to claim 7, wherein: The power regulation circuit also includes a low-pass filter, and the bypass circuit forms a part of the low-pass filter, thereby limiting the current to flow from the first end of the circuit path to the second end of the circuit path only through the low-pass filter when the device is in contact communication with the terminal and the switching element is in an open circuit configuration.

13. The device according to any one of claims 1 to 5, wherein: The module also includes a noise mitigation circuit configured to store charge using power harvested from received wireless signals when the device enters range of the terminal and to provide required current for one or more components of the module to inhibit current from being drawn from the antenna during operation of these components.

14. The device according to claim 13, wherein: The noise mitigation circuit is located within the power harvesting unit.

15. The apparatus according to claim 13, wherein: The noise mitigation circuit comprises one or more charging elements for storing charge, the charging elements being arranged to discharge to provide the required current.

16. The device according to claim 15, wherein: The noise mitigation circuit includes a rectifier circuit coupled to the antenna and configured to output a rectified voltage to charge a first charging element, and a power regulation circuit coupled to the rectifier circuit, the power regulation circuit configured to output a regulated voltage to charge a second charging element.

17. The apparatus according to claim 15, wherein: The noise mitigation circuit also includes a control block configured to control an amount of current provided from the charging element to the one or more components based on a deviation in a required current from those components.

18. The apparatus according to claim 16, wherein: The power regulation circuit includes a first branch and a second branch, the first branch including a first voltage regulator coupled to a first component of the module, and the second branch including a second voltage regulator coupled to a second component of the module, the first branch and the second branch are each connected to a common node coupled to the rectifier circuit, the first voltage regulator being configured to output a different regulated voltage level than the second voltage regulator.

19. The apparatus according to claim 18, wherein: The first component of the module is an ASIC configured to control a sensor forming part of the module, and the second component of the module is a microcontroller unit, and wherein the first voltage regulator is configured to output a higher regulated voltage than the second voltage regulator.

20. The apparatus of claim 18, wherein: The first voltage regulator is a low dropout regulator and the second voltage regulator is a switch mode power supply.

21. The apparatus of claim 13, wherein: The noise mitigation circuit is local to a component of the module.

22. The apparatus according to any one of claims 1 to 5, wherein: The device is configured to communicate with the terminal according to the ISO 14443 standard and / or the ISO 7816 standard.

23. The apparatus according to any one of claims 1 to 5, wherein: The first function is one of: ID verification; physical access control; financial transaction; personal information retrieval; health record retrieval.

24. The apparatus according to any one of claims 1 to 5, wherein: The module is a biometric sensor module and the second function is biometric authentication or registration of a user.

25. The apparatus of claim 16, wherein: The noise mitigation circuit also includes a sense block configured to detect a deviation in a desired current of one or more components of the module and to control a current supplied from the power regulation circuit based on the measured deviation in the desired current.

26. The apparatus of claim 19, wherein: The module also includes a sensor, a first noise mitigation circuit local to the microcontroller unit, and a second noise mitigation circuit local to the sensor.

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