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Related Manuals for NXP Semiconductors PN5180
Summary of Contents for NXP Semiconductors PN5180
- Page 1 AN11740 PN5180 Antenna design guide Rev. 1.1 — 19 June 2018 Application note 345311 COMPANY PUBLIC Document information Info Content Keywords PN5180, Antenna design, Antenna tuning Abstract This document describes the “standard” antenna design and tuning related to the PN5180.
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Page 2: Contact Information
AN11740 NXP Semiconductors PN5180 Antenna design Revision history Date Description 20180619 Editorial updates 20151119 First release Contact information For more information, please visit: http://www.nxp.com AN11740 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2018. All rights reserved. -
Page 3: Introduction
PN5180 Antenna design 1. Introduction The antenna design for the PN5180 is not much different than the antenna design for most of the other NXP reader ICs in general. However, some PN5180 specific details need to be considered to get an optimum performance. -
Page 4: Fig 1. Nfc Communication Modes
AN11740 NXP Semiconductors PN5180 Antenna design For the optimization of the performance it might makes sense to restrict the functionality to only one or two of the communication modes. (1) ISO/IEC 14443 PICC and PCD here just indicate the similarity of the communication but do not automatically mean interoperability. -
Page 5: Fig 2. Magnetic Coupling Between Reader (Pcd) And Card (Picc)
AN11740 NXP Semiconductors PN5180 Antenna design (1) k = coupling coefficient (2) Φ = magnetic flux Fig 2. Magnetic coupling between reader (PCD) and card (PICC) According to the ISO/IEC 14443 the PICC antenna coils can be categorized into the classes 1 …6, as shown in Fig 3. -
Page 6: Fig 3. Picc Classes According To The Iso/Iec 14443
AN11740 NXP Semiconductors PN5180 Antenna design (1) A PCD must always support the classes 1, 2, and 3. The Classes 4, 5 and 6 are optional. Fig 3. PICC Classes according to the ISO/IEC 14443 The PCD antenna coil sizes are not specified. So, for ISO/IEC 14443 compliant readers... -
Page 7: Fig 4. Iso/Iec 10373-6 Referencepicc
AN11740 NXP Semiconductors PN5180 Antenna design (1) Details see [3]. Fig 4. ISO/IEC 10373-6 ReferencePICC Some ReferencePICCs, which are commercially available (e.g. Fig 5), are pre-calibrated and equipped with several jumper options to address the most relevant tests with a single ReferencePICC. -
Page 8: Field Strength Tests
AN11740 NXP Semiconductors PN5180 Antenna design Note: This application note does not replace the detailed test description in the ISO/IEC 10373-6. There is no common certification process for ISO/IEC14443 compliance in place, even though many national bodies use the ISO/IEC 14443 to operate the electronic passports and electronic ID cards. -
Page 9: Emvco Specifics
AN11740 NXP Semiconductors PN5180 Antenna design 2. a signal generator with a pattern generator, that provides the load modulation signal as a response to the PCD test commands. The response must be triggered by the PCD test command, i.e. the signal generator needs a delayed trigger input either from the field or from the PCD itself. -
Page 10: Fig 6. Emvco Pos Operating Volume Requirement
AN11740 NXP Semiconductors PN5180 Antenna design (1) Details see [6]. Fig 6. EMVCo POS operating volume requirement Within this volume the given parameters need to be fulfilled. 2.2.2 EMVCo field strength For the field strength test, it is preferred to have the PCD send a continuous carrier, i.e. it performs no modulation. -
Page 11: Fig 7. Emvco Pos Reader Antenna Size
AN11740 NXP Semiconductors PN5180 Antenna design (1) Side length of a square antenna. (2) These simulation results do neither take any specific environment nor loading effects into account. Fig 7. EMVCo POS Reader antenna size 2.2.3 EMVCo Wave shapes The PCD needs to send the related pulse(s): It may send an EMVCo REQA and / or REQB. -
Page 12: Fig 8. Nfc Forum Operating Volume
AN11740 NXP Semiconductors PN5180 Antenna design The load modulation tests require 6. a calibrated ReferencePICC, which is placed at each of the given position (see Fig 7. a signal generator with a pattern generator, that provides the load modulation signal as a response to the PCD test commands. -
Page 13: Fig 9. Pcd & Picc Antenna Coil System
AN11740 NXP Semiconductors PN5180 Antenna design 3. Generic PCD antenna design rules Some of the antenna and analog design rules are very common for NXP NFC Reader designs, i.e. they do neither specifically depend on the used standard (ISO, NFC or EMVCo) nor depend on the NXP Reader IC but rather on physical or technical basics. -
Page 14: Number Of Turns
AN11740 NXP Semiconductors PN5180 Antenna design µ ⋅ ⋅ ⋅ = Card antenna coil area, fixed = Card antenna coil single turn inductance, fixed = Reader coil single turn inductance r = Reader Antenna coil radius x = Operating distance in the center of the Reader antenna µ... -
Page 15: Fig 10. Inductance Examples Versus Coil Radius
AN11740 NXP Semiconductors PN5180 Antenna design (1) Green area: target area for standard antenna matching. Fig 10. Inductance examples versus coil radius On the other hand, the number of turns defines the relationship of voltage level versus current level. Especially for the load modulation (see Fig 11) it might be helpful to increase the number of turns on the PCD antenna coil. -
Page 16: Fig 12. Coupling Coefficient Vs Pcd Antenna Radius
AN11740 NXP Semiconductors PN5180 Antenna design 3.1.2 Optimum Antenna Coil size Fig 12 shows the coupling coefficient versus antenna radius for three different operating distances. The scaling of the coupling coefficient does not necessarily show the correct absolute value, since some of the fixed parameters are estimated only for this graph. -
Page 17: Fig 13. Maximum Coupling Vs Antenna Size
AN11740 NXP Semiconductors PN5180 Antenna design The maximum coupling coefficient versus the operating distance can be estimated as shown in Fig 13. This maximum coupling is related to the optimum antenna size. (1) The absolute scale of k might not be correct due to simplifications. -
Page 18: Fig 14. Operating Distance X Versus Antenna Size
AN11740 NXP Semiconductors PN5180 Antenna design (1) Minimum required field strength Hmin = 1.5A/m (2) Both antennas scaled to deliver Hmax = 7.5 A/m at maximum Fig 14. Operating distance x versus antenna size ≈ 4x I Note: The large antenna is driven with a current I... -
Page 19: Fig 15. Magnitude Of Field Strength In 1 Cm Distance
The PN5180 evaluation board and its related description (see [9]) can be taken as a reference. The Fig 16 and Fig 17 show a part of the top and bottom layer structure around the PN5180 as reference. The GND layer is a complete area of one of the middle layers (not shown). AN11740 All information provided in this document is subject to legal disclaimers. -
Page 20: Fig 16. Pn5180 Layout Reference Board Top Layer
PN5180 Antenna design (1) Part of the top layer (2) Middle Layer = GND area Fig 16. PN5180 Layout Reference Board Top layer AN11740 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2018. All rights reserved. -
Page 21: Fig 17. Pn5180 Layout Reference Board Bottom Layer
Fig 17. PN5180 Layout Reference Board Bottom layer 4. PN5180 hardware design The PN5180 is optimized to support the NFC, ISO and EMVCo with a minimum of additional components. The PN5180 simply requires the antenna matching circuitry, some block capacitors and the crystal. -
Page 22: Fig 18. Typical Pn5180 Analog Circuit
(2) Tbd: “to be defined”, need to be defined using this document. (3) CXx, CAntx, C0x, C1x and C2x must be NP0. Fig 18. Typical PN5180 analog circuit (1) Names to be adapted! (2) Tbd: “to be defined”, need to be defined using this document. -
Page 23: Pn5180 Requirements
< ±1% are recommended. 4.1 PN5180 requirements The PN5180 is optimized to support the EMVCo operating volume. Therefore, the Tx output can drive up to ITVDD = 250mA. Based on a power supply voltage VBAT = TVDD = 5V that means a possible total power consumption for the total antenna circuit of up to >... -
Page 24: Fig 20. Itvdd Versus Antenna Impedance
4.2 Antenna for reader mode If the PN5180 is used in pure reader mode only, i.e. the PN5180 is not used in card mode or as passive P2P target, the ANT1 and ANT2 pins do not need to be used. -
Page 25: Fig 21. Pn5180 Reader Only Antenna Matching Circuit
15. Correction and assembly The details of those steps are described in with an example, using the PN512 Bueboard antenna together with the PN5180. The blocks and components are used as shown in Fig 21. (1) This circuit only covers the Tx part. -
Page 26: Fig 22. Measurement 1 Antenna Coil Of Pn512 Blueboard
AN11740 NXP Semiconductors PN5180 Antenna design (1) Measurement with R&S ZVL Fig 22. Measurement 1 Antenna coil of PN512 Blueboard (1) Measurement with miniVNA Pro and vna/J Fig 23. Measurement 2 Antenna coil of PN512 Blueboard In this example the antenna coil is measured with these values: L = 1.5 µH... -
Page 27: Define Target Impedance And Q-Factor
AN11740 NXP Semiconductors PN5180 Antenna design = 2.8 … 3.4Ω Coil = not measured, can be estimated The inductance can be measured quite accurate, but the resistance is not very accurate due to the relationship between R and jωL. And the capacitance is not measured at all with this simple measurement. -
Page 28: Define The Emc Filter
AN11740 NXP Semiconductors PN5180 Antenna design Note: The lower the Q, the better the stability and robustness of the antenna is. Antennas with lower Q show less detuning. The higher the Q, the higher the field strength is. Note: The final Q must be tuned with the pulse shape measurements, if the antenna shall be fully optimized. -
Page 29: Fig 24. Tuning Options
Q factor of the antenna coil circuit itself. This tuning is available with the PN5180 like with any other NXP Reader IC and shown in the following sections, too. Based on this the following EMC filter values are chosen:... -
Page 30: Calculate The Matching Components
NXP Semiconductors PN5180 Antenna design EMVco specifications as well as the ITVDD limit of the PN5180 (250mA), if the antenna impedance is low as such (i.e. in the typically required range of 20 Ω). The PN5180 provides a special function to dynamically control the ITVDD, which is called DPC. -
Page 31: Fig 25. Antenna Matching Calculation (Asymmetrical Tuning)
AN11740 NXP Semiconductors PN5180 Antenna design Note: For the symmetrical tuning the Rq might be much lower, since the EMC filter with lower cut off frequency improves the transfer function. This can increase the maximum possible field strength. (1) Excelsheet from www.nxp.com... -
Page 32: Fig 26. Rfsim99 Schematic
= 33pF + 8.2pF = simulation real 41.2pF). (1) The “measurement GND” (= simulation GND) is not the PN5180 and evaluation board GND! Fig 26. RFSIM99 Schematic AN11740 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2018. All rights reserved. -
Page 33: Fig 27. Rfsim99 Simulation Result
AN11740 NXP Semiconductors PN5180 Antenna design a. L0 = ideal component b. L0 = using simple physical model Fig 27. RFSIM99 Simulation result AN11740 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2018. All rights reserved. -
Page 34: Fig 28. Impedance Measurement Example
AN11740 NXP Semiconductors PN5180 Antenna design 4.2.1.6 Assembly and measurement After the first assembly the impedance measurement must be done, as shown in an example in Fig 28. (1) A simple 2-pin connector is soldered between TX1 and TX2 to simplify the impedance measurement. -
Page 35: Fig 29. Measurement Result Of First Assembly
AN11740 NXP Semiconductors PN5180 Antenna design (1) This matching does not meet the requirements. It must be corrected and retuned. Fig 29. Measurement result of first assembly 4.2.1.7 Impedance adaptation in simulation The easiest and fastest way to (fine) tune the antenna is to first of all adapt the simulation in such a way that it shows the same result as the reality. -
Page 36: Fig 30. Impedance Adaptation In The Simulation (Result)
AN11740 NXP Semiconductors PN5180 Antenna design c. Impedance first step d. Impedance after adaptation Fig 30. Impedance adaptation in the simulation (result) a. Circuit first step b. Circuit after adaptation Fig 31. Impedance adaptation in the simulation (circuit) With these adapted values of the antenna coil the last step of the final tuning can be done: La = L = 1.5µH... -
Page 37: Fig 32. Final Tuning Simulation
AN11740 NXP Semiconductors PN5180 Antenna design 4.2.1.8 Impedance correction and assembly The tuning of the impedance is now corrected with the values of C1 and C2, as shown in Fig 32. a. Final simulation circuit b. Final Simulation result Fig 32. Final tuning simulation These values are assembled, and the impedance is measured. -
Page 38: Fig 33. Final Tuning Measurement Result
4.2.2 Loading effect The target impedance of the antenna design defines the ITVDD (driver current of the PN5180) and the output power (i.e. operating distance for a given antenna coil) as shown in section 3. The lower the impedance gets, the higher the ITVDD becomes. Especially for high power reader design, where the impedance is quite low to achieve a maximum of field strength (as e.g. -
Page 39: Fig 34. Antenna Impedance Example With Reference Picc Loading
AN11740 NXP Semiconductors PN5180 Antenna design (1) ITVDDloaded < ITVDDunloaded Fig 34. Antenna impedance example with Reference PICC loading The change of the impedance curve indicates a lower ITVDD under loading conditions. That implies that with the above shown antenna matching the loading with ReferencePICCs (or typical smart cards) does even decrease the field strength and ITVDD. -
Page 40: Fig 35. Antenna Impedance Example With Smart Phone Loading
4.2, except the PLM connection, using the CANT1 and CANT2. The two related pins of the PN5180 (ANT1 and ANT2) are used to drive the passive load modulation (PLM) in card emulation mode or when the PN5180 is used as passive target. -
Page 41: Fig 36. Rm Antenna Matching With Low And High Impedance
The antenna tuning supporting both reader mode (RM) and card mode (CM) needs to consider the ANT1 and ANT2 pins of the PN5180. In CM these pins are in “high Z” state, in RM the ANBT1 and ANT2 are low. -
Page 42: Fig 37. Nfc Antenna In Rm
AN11740 NXP Semiconductors PN5180 Antenna design (1) 10Ω||22pF for simulation of the PN5180 (ANT1 and ANT2) in RM Fig 37. NFC antenna in RM The Fig 38 shows the simulation and measurement result. Note: The measurement must be done with 10 bridging the ANT1 and ANT2 pins. -
Page 43: Fig 39. Nfc Antenna In Cm
AN11740 NXP Semiconductors PN5180 Antenna design (1) 4kΩ||22pF for simulation of the PN5180 (ANT1 and ANT2) in CM Fig 39. NFC antenna in CM The simulation and measurement result is shown in Fig 40. The resonance frequency in CM is approximately 16MHz. -
Page 44: Optimizing The Transmitting
The NFC Cockpit (GUI) supports this optimization procedure, refer to [9] for details regarding the evaluation board and the use of the GUI. In a typical PCD design the output stage of the PN5180 is used with the maximum available output power, and the overall power consumption (and field distribution) is limited with the antenna impedance. -
Page 45: Fig 41. Tx_Clk_Mode_Rm
PN5180 Antenna design 4.4.3 Tx envelope shape The PN5180 provides some registers to adjust the wave shapes. The following description is a generic description. A more detailed description can be found in [14] and [15], since it is mainly related to the DPC antenna tuning. -
Page 46: Fig 42. Tx Envelope Shaping
AN11740 NXP Semiconductors PN5180 Antenna design (1) TX_SET_TAU_MOD_FALLING & TX_SET_TAU_MOD_RISING (2) TX_SET_SLEW_SHUNTREG Fig 42. Tx envelope shaping For a standard asymmetrical antenna design typically, the fastest rise and fall times for the envelope is required: The fastest rise and fall times (only defined by the system-Q factor) – exemplarily shown in Fig 41 (right hand side) - can be achieved by means of using: •... -
Page 47: Fig 43. Pn5180 Rx Block Diagram
The NFC Cockpit (GUI) supports this optimization procedure, refer to [9] for details regarding the evaluation board and the use of the GUI. The default settings in the EEPROM are optimized for the PN5180 based on the 65mm x 65mm evaluation board antenna. Some of these settings typically must be adjusted and optimized for other antenna designs. -
Page 48: Test And Debugging
AN11740 NXP Semiconductors PN5180 Antenna design Note: The AGC only measures the Rx voltage level of the RxP. Normally the voltage level at RxN and RxP should be the same. However, in case of wrong assembly or a bad symmetry the voltage level might be different at both pins. Therefore, a voltage measurement might be useful to ensure symmetry of the antenna tuning and layout. -
Page 49: Example Type B
The yellow signal shows the ADC output of the demodulated subcarrier (unfiltered Q channel). The orange signal shows the phase shifts, as detected by the PN5180. The screenshot on the right-hand side of Fig 44 shows the same response with the same test signals, but horizontally zoomed into a character of the type B response. -
Page 50: Fig 44. Type B Response With Test Signals
AN11740 NXP Semiconductors PN5180 Antenna design a. Type B response f. Type B response Zoom in b. Green: LMA (RefPICC input) g. Green: LMA (RefPICC input) c. Blue: TX_ACTIVE (Trigger) h. Blue: TX_ACTIVE (Trigger) d. Yellow: unfiltered Q-Channel i. Yellow: unfiltered Q-Channel e. -
Page 51: Fig 45. Test Signals For Type B, Comparison Of Rxgain
AN11740 NXP Semiconductors PN5180 Antenna design a. RxGain = 2; HPCF = 0 f. RxGain = 3; HPCF = 0 b. Green: LMA (RefPICC input) g. Green: LMA (RefPICC input) c. Blue: TX_ACTIVE (Trigger) h. Blue: TX_ACTIVE (Trigger) d. Yellow: unfiltered Q-Channel i. -
Page 52: Fig 47. Type B Without Card Response
MinLevel can be seen as a threshold value for the subcarrier signal on I and Q channel. The sub carrier signal must exceed the threshold to be taken into account by the PN5180 decoder. Note: The MinLevel is dynamically adapted inside the PN5180, i.e. with a very high level of subcarrier signal the Minlevel is automatically increased internally to increase the signal to noise ratio. -
Page 53: Fig 48. Type B With Card Response
AN11740 NXP Semiconductors PN5180 Antenna design As can be seen in Fig 48, the card response can be properly received in Fig 48a, where no noise applies. In Fig 48b the card response together with the noise is shown. The noise spikes, which are much larger than the sub carrier signal itself, introduce some clipping effects, which are detected like phase shifts. -
Page 54: Fig 49. Examples Of Vector Network Analyzers
AN11740 NXP Semiconductors PN5180 Antenna design 5. Annex This annex describes some basics about impedance measurement and the related measurement tools. 5.1 Vector Network Analyzer The impedance measurement must be done with a vector network analyzer, e.g. as shown in Fig 49. -
Page 55: Fig 50. Vna/J From Dl2Sba (Refer To [13])
AN11740 NXP Semiconductors PN5180 Antenna design a. VNA/J with antenna coil measurement b. VNA/J Smith chart example Fig 50. VNA/J from DL2SBA (refer to [13]) In Fig 51 the result of the same measurement is shown for the R&S ZVL as well as for the VNA/J using the miniVNAPro. -
Page 56: Impedance Measurement
The mismatch due to this setup error can be neglected. The power level must be low enough (e.g. 0dBm or less), and the PN5180 must be unpowered. Then the PN5180 can remain in the circuit, while measuring the S11 between TX1 and TX2. -
Page 57: Fig 52. Measurement Connector And Calibration Kit
AN11740 NXP Semiconductors PN5180 Antenna design (1) The mismatch due to the unbalanced measurement of a balanced impedance can be ignored. Fig 52. Measurement connector and calibration kit After the calibration the measurement setup should be checked and should show the results as shown in Fig 53. -
Page 58: References
[12] MiniVNA Pro, http://miniradiosolutions.com/minivna-pro/ [13] VNA/J from Dietmar Krause, DL2SBA, http://www.dl2sba.com/ [14] AN11741 PN5180 DPC antenna design, document number 3454xx [15] AN11742 PN5180 Dynamic Power Control, document number 3455xx AN11740 All information provided in this document is subject to legal disclaimers. -
Page 59: Legal Information
NXP Semiconductors products in such equipment or applications and therefore such inclusion and/or use is at the customer’s own Purchase of an NXP Semiconductors IC that complies with one of the Near Field risk. Communication (NFC) standards ISO/IEC 18092 and ISO/IEC 21481 does not convey an implied license under any patent right infringed by implementation of Applications —... -
Page 60: Table Of Contents
Magnitude of field strength in 1 cm distance ... 19 Fig 51. Impedance Measurement result example (Smith chart) ............... 55 Fig 16. PN5180 Layout Reference Board Top layer ... 20 Fig 52. Measurement connector and calibration kit ..57 Fig 17. PN5180 Layout Reference Board Bottom layer ................ -
Page 61: List Of Tables
AN11740 NXP Semiconductors PN5180 Antenna design 9. List of tables Table 1. Q-factor ............27 Table 2. Most relevant analog test signals ....49 AN11740 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2018. All rights reserved. -
Page 62: Contents
List of tables ............61 3.1.2 Optimum Antenna Coil size ......16 Contents ............. 62 Layout recommendations ......... 19 PN5180 hardware design ........21 PN5180 requirements ........23 Antenna for reader mode ......... 24 4.2.1 Antenna matching ..........24 4.2.1.1 Measure the antenna coil .........
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