Charge pump stage and method of implementing the same

Abstract

According to a first aspect of the present disclosure, a charge pump stage for use in a radio frequency identification (RFID) tag is provided, the charge pump stage comprising at least one bias generation unit, wherein the bias generation unit comprises a bias source and a bias element, and an adjustment element coupled in series to the bias source and the bias element, wherein the adjustment element is configured to adjust a current or a voltage provided by the bias source to the bias element. According to a second aspect of the present disclosure, a corresponding method of implementing a charge pump stage for use in a RFID tag is conceived.

Description

Technical Field

[0001] This disclosure relates to a charge pump stage. Furthermore, this disclosure relates to a corresponding method for implementing a charge pump stage. Background Technology

[0002] The backscatter power level of a Radio Frequency Identification (RFID) transponder (commonly referred to as an "RFID tag") is a crucial parameter for achieving reliable communication between the transponder and the reader device. Therefore, the performance of an RFID tag is typically evaluated based on this backscatter power level. Furthermore, requirements may be established specifying minimum limits for this backscatter power level. However, ensuring that RFID tags meet these requirements can be challenging. Summary of the Invention

[0003] According to a first aspect of this disclosure, a charge pump stage for use in a radio frequency identification (RFID) tag is provided, the charge pump stage comprising: at least one bias generating unit, wherein the bias generating unit includes a bias source and a bias element; and an adjustment element coupled in series to the bias source and the bias element, wherein the adjustment element is configured to adjust a current or voltage supplied by the bias source to the bias element.

[0004] In one or more embodiments, the regulating element includes a control input node configured to receive a control input for regulating the current or voltage.

[0005] In one or more embodiments, the control input node is coupled to an internal node of the charge pump stage or to an internal node of another charge pump stage of the RFID tag.

[0006] In one or more embodiments, the control input node is coupled to the control circuitry of the RFID tag.

[0007] In one or more embodiments, the adjustment element is directly coupled to the output of the bias source and to the input of the bias element.

[0008] In one or more embodiments, the adjustment element is coupled in series to the input of the bias source, and the output of the bias source is coupled to the input of the bias element.

[0009] In one or more embodiments, the bias source includes a first portion and a second portion, wherein the adjustment element is directly coupled to the output of the first portion of the bias source, and wherein the adjustment element is coupled to the input of the bias element through the second portion of the bias source.

[0010] In one or more embodiments, the bias source is implemented as a bias charge pump.

[0011] In one or more embodiments, the regulating element is implemented as an N-channel metal-oxide-semiconductor (NMOS) transistor or as a P-channel metal-oxide-semiconductor (PMOS) transistor.

[0012] In one or more embodiments, the regulating element includes a plurality of devices, wherein the devices are configured to regulate the current or voltage based on a single control input or a plurality of control inputs having a single or different signal polarities.

[0013] In one or more embodiments, the device is implemented as an NMOS transistor or as a PMOS transistor.

[0014] In one or more embodiments, a charge pump includes a charge pump stage of the type described.

[0015] In one or more embodiments, an RFID tag includes a charge pump of the type described.

[0016] In one or more embodiments, the regulating element is configured to be controlled depending on the operating mode of the RFID tag.

[0017] According to a second aspect of this disclosure, a method for implementing a charge pump stage in a radio frequency identification (RFID) tag is envisioned, the method comprising: providing at least one bias generating unit to the charge pump stage, wherein the bias generating unit includes a bias source and a bias element; and providing an adjustment element to the charge pump stage, the adjustment element being coupled in series to the bias source and the bias element, wherein the adjustment element is configured to adjust a current or voltage provided by the bias source to the bias element. Attached Figure Description

[0018] The embodiments will be described in more detail with reference to the accompanying drawings.

[0019] Figure 1 An example of an RFID front end for a radio frequency identification (RFID) tag integrated circuit (IC) is shown.

[0020] Figure 2 An example of a radio frequency (RF) charge pump is shown.

[0021] Figure 3 An example of a charge pump stage is shown.

[0022] Figure 4 An example of a bias generation unit is shown.

[0023] Figure 5 Another example of a bias generation unit is shown.

[0024] Figure 6 Another example of a bias generation unit is shown.

[0025] Figure 7 An illustrative embodiment of a charge pump stage is shown.

[0026] Figure 8 An illustrative embodiment of a method for implementing a charge pump stage is shown.

[0027] Figure 9 An illustrative embodiment of the bias generation unit is shown.

[0028] Figure 10 Another illustrative embodiment of the bias generation unit is shown.

[0029] Figure 11 Another illustrative embodiment of the bias generation unit is shown.

[0030] Figure 12 The normalized equivalent parallel input resistance (R) of the RFID tag IC is shown. P ) and the Normalized Powered Tag Forwarding (POTF) of the RFID tag.

[0031] Figure 13 The normalized power-on tag inversion (POTR) of the RFID tag and the normalized POTF of the RFID tag are shown. Detailed Implementation

[0032] The backscatter power level of an ultra-high frequency (UHF) RFID tag is known as Powered Tag Reversal (POTR). This parameter significantly impacts the robustness of communication between the RFID tag and the reader device. Therefore, RFID tag performance is often evaluated based on POTR, and requirements may be established specifying minimum limits for POTR at certain power levels received by the RFID tag. The characteristics of POTR, along with the RFID tag's received power level (represented as Powered Tag Forwarding (POTF), largely depend on the equivalent parallel resistance (Ro) of the RFID tag's integrated circuit (IC). P The behavior of RFID tag ICs. P Typically, the POTF decreases as it rises above the tag's minimum required operating power level, POTF0. The R of the RFID tag IC... PThe reduction is caused on the one hand by the nonlinear behavior of the rectifier—more specifically by the nonlinear behavior of the RF charge pump, which provides the internal power supply to the RFID tag IC from the received reader signal—and on the other hand by the required limitation of the internal power supply voltage level to prevent overvoltage conditions at the circuit elements of the RFID tag IC. Generally, it may be difficult to increase the backscatter power level of the RFID tag IC.

[0033] Figure 1 An example of an RFID front-end 100 for an RFID tag IC is shown. The RFID front-end 100 includes a first antenna terminal 102, a second antenna terminal 104, an electrostatic discharge (ESD) protection block 106, a radio frequency (RF) limiter 108, an antenna tuning block 110, a modulator 112, a demodulator 114, an RF charge pump 116, a voltage limiter 118, and a power supply voltage node 120 for the RFID tag circuitry (i.e., the tag IC). The RF charge pump 116 is configured to rectify and transform the RF voltage received from the antenna through the antenna terminals 102 and 104, and to provide a DC power supply voltage to the core circuitry (not shown) of the chip (i.e., the tag IC) (e.g., the digital portion of the tag IC and the non-volatile memory). The modulator 112 is configured to modulate the input impedance to modulate the signal scattered back from the antenna to transmit information to an external RFID reader (not shown). Furthermore, the demodulator 114 is configured to demodulate the amplitude-modulated signal transmitted by the reader. Antenna tuning block 110 is configured to tune the chip input capacitor to maximize power transfer from the antenna to the chip input. ESD protection block 106 is typically implemented using anti-parallel pn junction diodes. RF limiter 108 is configured to limit the RF voltage amplitude at antenna terminals 102, 104 under high received power levels on the connected antenna. Furthermore, voltage limiter 118 is configured to limit the output voltage (i.e., voltage vcp) of the RF charge pump to prevent degradation or damage to the connected core circuitry due to overvoltage.

[0034] Figure 2 An example of an RF charge pump 200 is shown. The RF charge pump 200 includes multiple charge pump stages 202, 204, 206, 208, 210, and 212. Specifically, Figure 2A block diagram of a differential or balanced RF charge pump 200 is shown. Inputs RF1 and RF2 are coupled to a tag antenna and receive RF signals. The received signals at RF1 and RF2 are typically shifted approximately 180°. The DC inputs and outputs of charge pump stages 202, 204, 206, 208, 210, and 212 can be connected in series or parallel. Charge pump stages 202, 204, 206, 208, 210, and 212 can share additional internal signals. Each charge pump stage 202, 204, 206, 208, 210, and 212 provides DC voltage gain by rectifying the signals received at RF1 and / or RF2. Figure 2 As shown in the example, the DC inputs of the first parallel stage, 1.1 to 1.M, can be connected to the chip ground node GND. Similarly, the last parallel stage, N.1 to NM, can be connected to the output node vcp. The RF charge pump output voltage at node vcp can be used as the power supply voltage for the RFID transponder IC. Furthermore, the RF charge pump 200 can provide multiple power supply voltages at different outputs to power individual circuit domains of the RFID transponder IC. Alternatively, the RFID transponder IC can be configured using a single-ended front-end and RF charge pump circuitry. In the case of a single-ended circuitry configuration, such as... Figure 1 and 2 The front-end and RF charge pump nodes RF1 or RF2 shown are coupled to the ground node GND. The RF input and GND nodes of the single-ended RFID front-end and RF charge pump are coupled to the tag antenna.

[0035] Figure 3An example of a charge pump stage 300 is shown. The gate terminals of NMOS transistor M1 and PMOS transistor M2 are coupled to RF2 via capacitors C2 and C3, respectively. The source terminals of M1 and M2 are coupled to RF1 via capacitor C1. Two bias generation units 302 and 304 provide DC bias voltages at the gate nodes gn and gp of M1 and M2, respectively. Bias generation units 302 and 304 may be coupled to other internal nodes, such as vi, vc, or vo of the RF charge pump stage 300, but in some circuit implementations they are also coupled to RF1 and / or RF2. Bias generation units 302 and 304 may also be coupled to each other. Furthermore, bias generation units 302 and 304 may receive signals from another circuit block outside the RF charge pump stage 300. Bias generation units 302 and 304, or portions thereof, may be shared among multiple RF charge pump stages. Under a negative voltage swing at RF1, and therefore a positive voltage swing at RF2, transistor M1 becomes conductive, and charge is transferred from the DC input node vi to C1. In this first operating condition, transistor M2 transitions to a substantially non-conductive or low-conductivity state. Under a positive voltage swing at RF1, and therefore a negative voltage swing at RF2, transistor M2 becomes conductive, and charge stored on C1 is transferred to the DC output node vo. Similar to transistor M2 in the first operating condition, in this second operating condition, transistor M1 transitions to a low-conductivity state. Optimal efficiency in terms of output DC power provided at vi and vo relative to the RF power absorbed at RF1 and RF2 can be achieved by adjusting the bias voltages at gn and gp to balance the voltage drop at M1 and M2 during the charge transfer cycle with the reverse current in the low-conductivity states of M1 and M2. Therefore, the DC voltage levels at gn and gp relative to vc, corresponding to the gate-source voltages of M1 and M2 respectively, are typically adjusted to levels close to the transistor's threshold voltage Vth. Figure 3 As indicated, terminals RF1 and RF2 of the charge pump stage of the differential or balanced RF charge pump can be interchanged. In a single-ended RF charge pump circuit configuration, terminal RF2, coupled to C2 and C3, is connected to the ground node GND.

[0036] Figure 4 An example of a bias generation unit 400 is shown. Specifically, Figure 4 It shows that it can be used Figure 3 The diagram shows a block diagram of a bias generation unit 400 used in an RF charge pump stage. The bias generation unit 400 includes a bias source 402 and a bias element 404 coupled to each other. The bias source 402 provides current or voltage as input to the bias element 404. The bias element 404 derives a bias voltage from the received current or voltage at the output node bo by shunting current to a reference output br. For example, the outputs bo and br of the bias element 404 may be connected to... Figure 3 The nodes gn or gp and vi, vc or vo of the charge pump stage are shown. It should be noted that multiple charge pump stages may share the entire bias source and / or bias element, or a portion of the bias source and / or bias element.

[0037] Figure 5 Another example of the bias generation unit 500 is shown. Specifically, Figure 5 The bias source for the RF charge pump stage is shown to be implemented by means of a charge pump, referred to as a bias charge pump (bias CP) 502. The bias charge pump 502 receives RF signals at terminals RF1 and RF2, and provides DC current to the bias element 504 via a reference input terminal bi. Input bi can be connected, for example, to... Figure 3 The nodes vi, vc, or vo of the charge pump stage are shown.

[0038] Figure 6 Another example of the bias generation unit 600 is shown. Specifically, Figure 6 An exemplary circuit diagram of a charge pump bias generation unit 600 using a bias charge pump 602 is shown. More specifically, transistors M3, M4, and M5, combined with capacitors C4, C5, and C6, form a bias charge pump 602, which supplies current to a bias element 604 composed of transistor M6. The gate-source voltage of the diode-connected transistor M6 defines the bias voltage at node bo relative to a reference node br. For example, outputs bo and br may be connected to nodes gn and vi, respectively, and input bi may be connected to... Figure 3 The charge pump stage is shown at nodes vi, vc, or vo. With the increase in voltage magnitude at RF1 and RF2, the output current of the bias charge pump 602 increases. Transistor M6, due to its nonlinear characteristics, conducts the increased current to node br, and thus stabilizes the bias voltage at bo relative to br. In practice, the bias element 604 acts as a shunt regulator. Figure 6 The bias generation circuit shown is suitable for use in Figure 3 The NMOS transistor M1 of the charge pump stage shown is provided with a bias voltage at its gate node gn. Figure 3 The corresponding bias generation circuit for the PMOS transistor M2 can use a PMOS transistor as a bias element and a bias charge pump to provide current in the reverse direction, and... Figure 6 The bias generation circuits shown are complementary. When, as in Figures 3 to 6 When the charge pump stage, including its components, is used in an RFID tag as detailed in the diagram, the backscatter power level of the RFID tag may not be high enough.

[0039] We will now discuss charge pump stages and corresponding methods for implementing charge pump stages, which help increase the backscatter power level of RFID tags using said charge pump stages.

[0040] Figure 7 An illustrative embodiment of a charge pump stage 700 is shown. The charge pump stage 700 includes at least one bias generation unit 702. The bias generation unit 702 includes a bias source 704 and a bias element 708. Furthermore, the charge pump stage 700 includes a regulating element 706 coupled in series to the bias source 704 and the bias element 708. Because the regulating element 706 is coupled in series to the bias source 704 and the bias element 708, it can also be referred to as a "series regulating element". The regulating element 706 is configured to regulate the current or voltage supplied by the bias source 704 to the bias element 708. By including the regulating element 706 in the bias generation unit 702 of the charge pump stage 700, the backscatter power level of the RFID tag using the charge pump stage 700 can be more easily increased, especially at elevated receive power levels. More specifically, this is possible because the regulating element 706 enables improved regulation of the internal bias voltage of the charge pump in which the charge pump stage 700 is used.

[0041] In one or more embodiments, the regulating element includes a control input node configured to receive a control input for regulating the current or voltage. This allows for easier control of the regulating element. In one or more embodiments, the control input node is coupled to an internal node of the charge pump stage or to an internal node of another charge pump stage of the RFID tag. This allows for suitable control of the regulating element. Furthermore, in one or more embodiments, the control input node is coupled to the control circuitry of the RFID tag. This allows for alternative control of the regulating element, resulting in practical implementations of the charge pump stage.

[0042] In one or more embodiments, the regulating element is directly coupled to the output of the bias source and to the input of the bias element. This allows for a practical implementation of the bias generation unit. In one or more embodiments, the regulating element is coupled in series to the input of the bias source, and the output of the bias source is coupled to the input of the bias element. This allows for an alternative practical implementation of the bias generation unit. Furthermore, in one or more embodiments, the bias source includes a first portion and a second portion, wherein the regulating element is directly coupled to the output of the first portion of the bias source, and wherein the regulating element is coupled to the input of the bias element through the second portion of the bias source. This allows for another alternative practical implementation of the bias generation unit. Furthermore, in one or more embodiments, the bias source is implemented as a bias charge pump. This allows for a practical implementation of the bias source. Furthermore, in one or more embodiments, the regulating element is implemented as an N-channel metal-oxide-semiconductor (NMOS) transistor or a P-channel metal-oxide-semiconductor (PMOS) transistor. This allows for a practical implementation of the regulating element with relatively low complexity and low area cost.

[0043] In one or more embodiments, the regulating element includes multiple devices configured to regulate the current or voltage based on a single control input or multiple control inputs having single or different signal polarities. Furthermore, in one or more embodiments, the devices are implemented as NMOS transistors or PMOS transistors. In this way, practical implementations of the regulating element can be achieved with relatively low complexity and low area cost. For example, instead of a single NMOS or PMOS transistor, a transmission gate can be used as the regulating element, allowing for a unified RF charge pump stage design in combination with a central control circuit that provides only two control signals for all regulating elements across different charge pump stages. In one or more embodiments, the regulating element is configured to be controlled depending on the operating mode of the RFID tag in which the charge pump stage is used. For example, depending on whether the RFID tag operates in receive mode, transmit mode, memory read mode, memory write mode, or antenna tuning mode, the regulating element can be configured to be controlled in different ways. In this way, the internal bias voltage of the charge pump can be adjusted depending on the operating mode of the RFID tag, which can further improve the regulation.

[0044] Figure 8An illustrative embodiment of a method 800 for implementing a charge pump stage is shown. Method 800 includes the following steps. At step 802, at least one bias generating unit is provided to the charge pump stage, wherein the bias generating unit includes a bias source and a bias element. Furthermore, at step 804, an adjustment element is provided to the charge pump stage, the adjustment element being coupled in series to the bias source and the bias element, wherein the adjustment element is configured to adjust the current or voltage supplied by the bias source to the bias element. (See reference...) Figure 7 As mentioned in the corresponding charge pump stage shown, by including the adjustment element in the bias generation unit of the charge pump stage, it is easier to increase the backscatter power level of the RFID tag in which the charge pump stage is used.

[0045] Specifically, the charge pump stage and corresponding implementation method disclosed in this invention facilitate improved bias regulation of the RF charge pump for UHF RFID transponder ICs. Specifically, it enables increased R... P This allows for enhanced POTR at elevated receive power levels. To achieve this, a series regulating element is included in the bias generation of the RF charge pump. In this way, the magnitude of the bias voltage at the rising input voltage amplitude or receive power level can be limited, thereby preventing over-biasing of the rectifier device. The series regulating element can be easily controlled by means of a feedback connection to an internal node of the charge pump stage. Alternatively, the series regulating element can be controlled by a dedicated control circuit external to the RF charge pump.

[0046] Figure 9 An illustrative embodiment of a bias generation unit 900 is shown. The bias generation unit 900 includes a bias source 902, a bias element 906, and a series regulating element 904 series coupled to the bias source 902 and the bias element 906. The series regulating element 904 receives a control input ctr, which allows adjustment of the input current or voltage of the bias element 906, and thus adjusts (or more specifically, limits) the magnitude of the bias voltage provided by the bias element 906 and the magnitude of the rising input voltage or received power level received at RF1 and RF2. The control input ctr can be directly fed back to an internal node, such as an RF charge pump stage, etc. Figure 3The nodes vi, vc, or vo of the RF charge pump stage are shown. The control input ctr can also be connected to an internal node of another charge pump stage of the RF charge pump. The DC voltage level at the internal node of the RF charge pump varies with the amplitude of the input voltage and can therefore be adapted to directly control the series regulating element 904 to limit the magnitude of the bias voltage provided by the bias element 906. Alternatively, the control input ctr can receive a signal from a control circuit (not shown). The control circuit can use a signal indicating the voltage amplitude at RF1 and RF2 provided by a sensing circuit (not shown) or use the received power level to control the level of the input ctr. For example, the sensing circuit can evaluate the signal envelope of the RF signal at RF1 and RF2, or alternatively, measure the output voltage or output current of the RF charge pump. The control circuit can provide a continuous control signal or a digital signal as a control input to control the input node ctr. It should be noted that the bias generation unit of the RF charge pump may include multiple series regulating elements receiving multiple control inputs ctr with varying signal polarities. Such series regulating elements can be in active operating states that adjust the charge pump bias voltage during all operating modes of the RFID tag IC or only during specific modes such as the RFID tag IC's receive, transmit, memory read, memory write, and antenna tuning modes.

[0047] Figure 10 Another illustrative embodiment of a bias generation unit 1000 is shown. The bias generation unit 1000 uses a bias charge pump to provide current at the input of a bias element 1008. Generally, one or more series regulating elements may be connected between the bias charge pump and the bias element, or also between different portions of the bias charge pump. The latter is suitable for the bias generation unit 1000, which includes a bias charge pump having a first portion 1002 and a second portion 1006. In this embodiment, a series regulating element 1004 is coupled in series to the first portion 1002 and the second portion 1006 of the bias charge pump. It should be noted that a series regulating element (not shown) may be coupled in series to the input node bi of the bias charge pump.

[0048] Figure 11 Another illustrative embodiment of the bias generation unit 1100 is shown. Specifically, Figure 11 It shows Figure 10 The diagram shows an actual implementation of the bias generation unit. In this implementation, NMOS transistors M7, M8, and M9, combined with capacitors C7, C8, and C9, form a structure that provides current to the bias generation unit generated by the NMOS transistor M7. 10 The bias charge pump, consisting of bias element 1108, is connected in series with transistors M8 and M9, and thus between the first part 1102 and the second part 1106 of the bias charge pump, transistor M... 11Forming a series regulating element 1104. Transistor M 11 It receives a control input ctr at its gate terminal. The input node ctr can be connected, for example, to the node vc or vo of the RF charge pump stage, such as... Figure 3 As shown in the diagram. Relative to transistor M. 11 At the source terminal, the voltage level at vc or vo increases with the increase in voltage amplitude at RF1 and RF2. As a result, transistor M... 11 The drain-source channel conductance decreases with the increase in input voltage, thereby limiting the current and thus limiting the transistor M. 10 The gate-source voltage corresponds to the bias voltage at node bo relative to br. Alternatively, the input ctr may receive a signal from the control circuitry, as previously mentioned. It should be noted that, generally, the series regulating element may include one or more devices, such as NMOS and PMOS transistors, that allow adjustment of the conductance, and may receive multiple control input ctrs with varying signal polarities. For example, the series regulating element may consist of NMOS and PMOS transistors connected in parallel, which receive two control input signals with opposite signal polarities. Alternatively, adjustable conductance can also be implemented using switched capacitor circuitry techniques.

[0049] Figure 12 The graph 1200 shows the normalized R of the RFID tag IC of the RFID tag. P The normalized POTF of the RFID tag. Specifically, R as a function of POTF is shown in the first scenario 1202, in which no series adjustment element of the described type is used, compared to the second scenario 1204 in which a series adjustment element is used. P Lower.

[0050] Figure 13 A graph 1300 is shown, which displays the normalized POTR and normalized POTF of the RFID tag. Specifically, it shows that in the first scenario 1302, in which no series adjustment element of the described type is used, the POTR as a function of POTF is lower compared to the second scenario 1304, in which a second scenario 1304 uses a series adjustment element.

[0051] It should be noted that the above embodiments have been described with reference to different subjects. Specifically, some embodiments may have been described with reference to method-type technical solutions, while others may have been described with reference to device-type technical solutions. However, those skilled in the art will understand from the foregoing that, unless otherwise stated, any combination of features related to different subjects, specifically combinations of features of method-type technical solutions and features of device-type technical solutions, are also considered to be disclosed together with this document, except for any combination of features belonging to one type of subject matter.

[0052] Furthermore, it should be noted that the drawings are illustrative. Similar or identical elements in different drawings have the same reference numerals. Additionally, it should be noted that, in order to provide a concise description of illustrative embodiments, implementation details that are customary to those skilled in the art may not be described. It should be understood that, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developer's specific goals, such as complying with system-related and business-related constraints, which may vary in different implementations. Furthermore, it should be understood that such development work can be complex and time-consuming, but is merely a routine task for those skilled in the art in designing, manufacturing, and producing.

[0053] Finally, it should be noted that those skilled in the art will be able to devise numerous alternative embodiments without departing from the scope of the appended claims. Any reference numerals placed between parentheses in the claims should not be construed as limiting the scope of the technical solutions. The words "comprise(s)" or "comprising" do not exclude the presence of other elements or steps besides those listed in the technical solution. The words "a(a)" or "an" preceding an element do not exclude the presence of a plurality of such elements. The measures stated in the claims can be implemented by means of hardware comprising several different elements and / or by means of a suitably programmed processor. In a device technical solution listing several components, several of these components may be embodied by the same item of hardware. The mere fact that certain measures are stated in mutually different dependent technical solutions does not imply that a combination of these measures cannot be used advantageously.

[0054] List of reference numerals

[0055] 100 Radio Frequency Identification (RFID) Front End

[0056] 102 First Antenna Terminal

[0057] 104 Day 2 Line End

[0058] 106 Electrostatic Discharge (ESD) Protection

[0059] 108 Radio Frequency (RF) Limiter

[0060] 110 antenna tuning

[0061] 112 modulator

[0062] 114 demodulator

[0063] 116RF charge pump

[0064] 118 Voltage Limiter

[0065] Power supply voltage nodes of 120 RFID tag circuit

[0066] 200RF charge pump

[0067] 202 charge pump stage

[0068] 204 charge pump stage

[0069] 206 charge pump stage

[0070] 208 charge pump stage

[0071] 210 charge pump stage

[0072] 212 charge pump stage

[0073] 300 charge pump stage

[0074] 302 bias generation unit

[0075] 304 bias generation unit

[0076] 400 bias generation unit

[0077] 402 bias source

[0078] 404 bias element

[0079] 500 bias generation unit

[0080] 502 Bias Charge Pump (Bias CP)

[0081] 504 bias element

[0082] 600 bias generation unit

[0083] 602 Bias Charge Pump

[0084] 604 bias element

[0085] 700 charge pump stage

[0086] 702 bias generation unit

[0087] 704 bias source

[0088] 706 regulating element

[0089] 708 bias element

[0090] 800 Method for Implementing Charge Pump Stage

[0091] 802 provides at least one bias generation unit to the charge pump stage, wherein the bias generation unit includes a bias source and a bias element.

[0092] 804 provides a regulating element to the charge pump stage, the regulating element being coupled in series to a bias source and a bias element, wherein the regulating element is configured to regulate the current or voltage supplied from the bias source to the bias element.

[0093] 900 bias generation unit

[0094] 902 bias source

[0095] 904 series regulating element

[0096] 906 bias element

[0097] 1000 bias generation unit

[0098] The first part of the 1002 bias charge pump

[0099] 1004 series regulating element

[0100] Part 2 of the 1006 bias charge pump

[0101] 1008 bias element

[0102] 1100 bias generation unit

[0103] The first part of the 1102 bias charge pump

[0104] 1104 series regulating element

[0105] Part 2 of the 1106 bias charge pump

[0106] 1108 bias element

[0107] 1200 displays normalized R P Curve plot of normalized POTF

[0108] 1202 First scenario, without series adjustment element

[0109] 1204 Second Scenario, with series regulating element

[0110] 1300 displays the curves of normalized POTR and normalized POTF.

[0111] 1302 First Scenario: No series regulating element

[0112] 1304 Second Scenario, with series adjustment element.

Claims

1. A charge pump stage for use in radio frequency identification (RFID) tags, characterized in that, The charge pump stage includes: At least one bias generating unit, wherein the bias generating unit includes a bias source and a bias element; and An adjustment element, which is coupled in series to the bias source and the bias element, wherein the adjustment element is configured to adjust the current or voltage supplied by the bias source to the bias element.

2. The charge pump stage according to claim 1, characterized in that, The regulating element includes a control input node configured to receive a control input for regulating the current or voltage.

3. The charge pump stage according to claim 2, characterized in that, The control input node is coupled to an internal node of the charge pump stage or to an internal node of another charge pump stage of the RFID tag.

4. The charge pump stage according to claim 2, characterized in that, The control input node is coupled to the control circuit of the RFID tag.

5. The charge pump stage according to any one of the preceding claims, characterized in that, The adjustment element is directly coupled to the output of the bias source and the input of the bias element.

6. The charge pump according to any one of claims 1 to 4, characterized in that, The regulating element is coupled in series to the input of the bias source, and the output of the bias source is coupled to the input of the bias element.

7. The charge pump stage according to any one of claims 1 to 4, characterized in that, The bias source includes a first portion and a second portion, wherein the adjustment element is directly coupled to the output of the first portion of the bias source, and wherein the adjustment element is coupled to the input of the bias element through the second portion of the bias source.

8. A charge pump, characterized in that, Includes the charge pump stage according to any of the preceding claims.

9. An RFID tag, characterized in that, Includes the charge pump according to claim 8.

10. A method for implementing a charge pump stage in a radio frequency identification (RFID) tag, characterized in that, The method includes: At least one bias generation unit is provided to the charge pump stage, wherein the bias generation unit includes a bias source and a bias element; and A regulating element is provided to the charge pump stage, the regulating element being coupled in series to the bias source and the bias element, wherein the regulating element is configured to regulate the current or voltage supplied by the bias source to the bias element.

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