HF MultiProtocol Transceiver IC HF Training MultiProtocol Transceiver

HF Multi-Protocol Transceiver IC HF Training Multi-Protocol Transceiver IC KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 1

HF Multi-Protocol Transceiver IC ► Multi-Protocol Transceiver IC – – Complies with Tag-it™ protocol Complies with ISO 15693 -2. Complies with ISO 14443 -2 (Type A) Supports “Transparent Mode” ► Functionality RI-R 6 C-001 A KS/JAG 18 -NOV-03 – – – Short to mid range applications Low additional component count Low power consumption 200 m. W RF power into 50 Ohms Serial interface Copyright Texas Instruments Page 2

HF Multi-Protocol Transceiver IC ►Transceiver IC Pinouts 1 VDD_TX RX_IN 20 2 TX_OUT VSS_RX 19 3 R_MOD 4 VSS_TX 18 VDD_RX 17 5 XTAL 1 16 6 XTAL 2 SCLOCK 15 7 VSS_DIG 8 XTAL_CLK 9 10 KS/JAG 18 -NOV-03 M_ERR 14 DIN 13 VDD_DIG 12 DOUT 11 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 VDD_TX TX_OUT R_MOD VSS_TX XTAL 1 XTAL 2 VSS_DIG XTAL_CLK not used DOUT VDD_DIG DIN M_ERR SCLOCK not used VDD_RX not used VSS_RX RX_IN Transmitter power supply Output transistor drain connection External resistor to set 10% modulation depth mode Transmitter section ground Pin 1 of Xtal resonator Pin 2 of Xtal resonatorand external system clock input Digital section ground Buffered output of Xtal oscillator To be grounded for normal operation Data output for serial link Digital section power supply Data input for serial link Manchester Protocol error flag Serial link clock To be left unconnected for normal operation Receiver section power supply To be left unconnected for normal operation Receiver section ground Receiver input Copyright Texas Instruments Page 3

HF Multi-Protocol Transceiver IC HF Inductors e. g. EPCOS Q-60 ANTENNA 50 Ohm ± 10% Q = 10~30 Fres = 13. 56 ± 200 k. Hz VSWR = 1 ~1. 2 L 3 L 2 L 1 COAX C 1 Component C 1 C 2 C 3 C 4 C 5 C 6 C 7 C 8 C 9 C 10 L 1 L 2 L 3 L 4 R 1 R 2 HF Inductor e. g. EPCOS Q-60 1 C 5 L 4 C 6 2 R 2 C 7 3 4 5 XTAL 13. 56 MHz * 18 Ohm = 20% Modulation (Recommended) 12 Ohm = 10% Modulation KS/JAG 18 -NOV-03 C 4 VCC Value 47 p. F 10 n. F 47 p. F 10µF Tantalum 100 n. F 22 p. F 100 n. F 2. 7µH 5. 6µH 3. 3µH 2. 2 K Ohm 18 Ohm* C 2 6 C 9 7 8 VDD_TX RX_IN TX_OUT VSS_RX VDD_RX VSS_DIG XTAL_CLK 9 10 19 SCLOCK M_ERR DIN VDD_DIG DOUT C 8 17 16 XTAL 1 XTAL 2 R 1 18 R_MOD VSS_TX 20 15 VCC 14 13 12 VCC µC 11 C 10 Improved Matching Circuit Copyright Texas Instruments Page 4

HF Multi-Protocol Transceiver IC ► Matching circuit calculation: – Schematic of a double L matching circuit = T matching network Xs 1 Xs 2 5 Ohm 50 Ohm RF Xp 1 KS/JAG 18 -NOV-03 Xp 2 Copyright Texas Instruments Page 5

HF Multi-Protocol Transceiver IC Calculation: Q = 40 Rs = 5 W R = Rs × (Q 2 +1) Rl = 50 W f =13, 56 Mhz R = Virtual resistance (instead of Xp 1//Xp 2) Xs 1 = Q × Rs L 1 = Xs 1 2 ×p × f L 1 = 2, 3 m. H Xs 2 = Q 2 × Rl L 2 = Xs 2 2 ×p × f Xp 1 = C = KS/JAG 18 -NOV-03 R Q L 2 = 7, 4 m. H Q 2 = 1 2 ×p × ƒ × Xp R -1 Rl Xp 2 = R Q 2 Xp = Xp 2 × Xp 1 Xp 2 + Xp 1 C = 77 p. F Copyright Texas Instruments Page 6

HF Multi-Protocol Transceiver IC Caution: ■ Check the resonant frequency of the inductor! ■ Use only low tolerance components for the matching network to achieve optimum SWR! For Example: L 1 and L 2: C 2: Bad choice: KS/JAG 18 -NOV-03 +/-10% tolerance +/-2% tolerance, temp. coefficient +-30 ppm COG (Murata), Z 5 U material +22/-85% tolerance!!! Copyright Texas Instruments Page 7

HF Multi-Protocol Transceiver IC ► Suggested improvements to the application circuit: – Add a resistor between L 4/C 4 and TX_OUT/C 3 L 2 L 1 COAX 1 to 10 Ohms C 1 C 2 C 3 C 4 VCC 1 C 5 C 6 L 4 Rd 2 R 2 C 7 XTAL 13. 56 MHz 3 4 5 6 C 9 7 8 9 VDD_TX RX_IN TX_OUT VSS_RX VDD_RX 19 17 16 XTAL 1 XTAL 2 R 1 18 R_MOD VSS_TX 20 SCLOCK M_ERR VSS_DIG DIN XTAL_CLK VDD_DIG 10 DOUT 15 C 8 VCC 14 13 12 VCC µC 11 C 10 4 This action improves the EMC due to the decrease of the slew rate of the output MOS-FET. KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 8

HF Multi-Protocol Transceiver IC – Further decoupling of VCC and Interface lines with series resistance » Very cheap improvement regarding noise behavior – Split the receive and transmit ground-planes Connect » Better de-coupling of receiver – Avoid using RS 232 drivers that use switching frequencies in the range of 424 to 484 k. Hz or their harmonics (e. g. 141 k. Hz x 3 = 424 k. Hz) KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 9

HF Multi-Protocol Transceiver IC – Add 1 n. F ceramic capacitors in parallel to the C 6, C 8 and C 10, 100 n. F blocking capacitors at the IC VDD pins » These capacitors should be placed closest to the supply pins! » Ceramic capacitors have a much better HF noise filtering behavior due to their low inductance. SCLOCK M_ERR DIN VDD_DIG DOUT 15 14 13 12 VCC µC 11 1 n. F 100 n. F Example (C 10) KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 10

HF Multi-Protocol Transceiver IC ► Basic communication structure: Basic Request / Response Tran 1 switches the direction of SCLK S 1 and TAG commands generate a Reader SOF Symbolic S 1 ES 1 = Reader EOF cmd S 2 indicates a TAG SOF data= to be sent to TAG ES 1 TRAN 1 S 2 TAG data ES 2 indicates a TAG EOF ES 2 TRAN 2 Sclock Din Dout a SCLK Host controller driven KS/JAG 18 -NOV-03 b c d e f SCLK TAG driven Copyright Texas Instruments Page 11

HF Multi-Protocol Transceiver IC ► First steps after assembly of a prototype board: 1. Check soldering and schematic 2. Switch on power supply and check supply voltages 3. Check timing! Minimum timings T 1: 300 ns T 4: 600 ns T 2: 300 ns T 5: 300 ns T 3: 66 ns T 6: 300 ns KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 12

HF Multi-Protocol Transceiver IC 4. Read configuration register 0 x 71 hex (MSB first) Result = 0 x 22 (MSB first) SCLK DIN DOUT MERR KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 13

HF Multi-Protocol Transceiver IC 5. Write to configuration register 0 x 7 Dhex (MSB first) Content = 0 x 27 (MSB first) ISO 15693 / down link 1 out of 4, 100% modulation, one subcarrier (ASK) high datarate (~26 kb), Manchester decoder disabled SCLK DIN DOUT MERR KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 14

HF Multi-Protocol Transceiver IC 6. Read configuration register 0 x 71 hex (MSB first) Result = 0 x 27 (MSB first) SCLK DIN DOUT MERR KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 15

HF Multi-Protocol Transceiver IC 7. Switch on HF: This operation must be performed first, otherwise SOF of the reader is not modulated properly. HF-ON Symbolic S 1= Start Bit = 1 ES 1 = Stop Sclock Din KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 16

HF Multi-Protocol Transceiver IC 8. Send a read TAG command (e. g. get Inventory) ISO Command Set: KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 17

HF Multi-Protocol Transceiver IC ► Inventory Command Sequence: 0 x 2 B (Command, Transceiver) ISO 15693, 1 out of 4, 100% modulation, FM, high data-rate 0 x 27, (Request flags): Calculate CRC on these bytes 0 x 01, (Command, Tag): FM, high data-rate, use table 5 of ISO-spec, no protocol format extension, AFI not present, 1 slot, Option flag = 0, RFU = 0 (see ISO 15693 -3 for details) Inventory Command 0 x 00, Mask length: 0 0 x 2 A, 0 x 50 : CCITT-CRC (Reverse, Start value 0 x. FFFF, 1’s compliment) Command string : Command CRC 15693 Protocol 00101011 00100111 00000000 00101010000 = 0 x 2 B 0 x 27 0 x 01 0 x 00 0 x 2 A 0 x 50 MSB First LSB First 00101011 11100100 10000000 01010100 00001010 = 0 x 2 B 0 x. E 4 0 x 80 0 x 00 0 x 54 0 x 0 A KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 18

HF Multi-Protocol Transceiver IC u CRC calculation: For the ISO 15693 tag protocols use: u CCITT-CRC, Byte entry, Reverse direction, Start value 0 x. FFFF, 1’s Complement For the Tag-it™ HF tag protocol use: u CCITT-CRC, Bit entry, Forward direction, Start value 0 x. FFFF, 1’s Compliment KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 19

HF Multi-Protocol Transceiver IC Inventory command TAG answer DOUT HF SCLK MERR pulse indicates that modulation on HF is finished Two zeroes are added to the TAG answer in front of EOF! KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 20

HF Multi-Protocol Transceiver IC ► Register mode: Once the transceiver is initialized by the command byte in front of the data to be sent to the TAG, or by initializing the configuration register, the command byte does not need to be sent again, until the configuration needs changing again. KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 21

HF Multi-Protocol Transceiver IC ► Set timing initialization: 318, 64 – 323, 34 µs after the rising edge of EOF of the reader, the TAG should send its answer (ISO 15693 -3). SCLK MERR DOUT HF KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 22

HF Multi-Protocol Transceiver IC ► Checking the Delay ■ Due to differences in the circuitry, it is possible, that there might be an additional delay in the answer. ■ If this occurs, the Manchester decoder of the Transceiver IC will not work properly anymore. The first scan pulse has to be in front of the first modulation pulse of the TAG! ■ You can visualize the scan pulses of the Manchester decoder with following command sequence: 0 x 7 B Data: 1100 0101 0110 0 (Boundary scan ON, Tdelay = 319 µs) KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 23

HF Multi-Protocol Transceiver IC ► Solution - Change the Delay Timing offset [7 bits] Tdelay [µs] Minimum Value 306 µs 0000000 Typical 319 µs 0101100 Maximum Value 343 µs 1111111 Tdelay M_ERR Example: 7 bits = 0101100 = 2 C 1 Bit equals 295 ns hex = 44 dec 44 x 295 = 12980 n. S = 13 µs Tdelay = 306 + 13 = 319 µs KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 24

HF Multi-Protocol Transceiver IC ► Output power measurement: 22. 8 d. Bm = ~200 m. W KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 25

HF Multi-Protocol Transceiver IC ► Transponder modulation measurement: Oscilloscope single turn aircoil TAG MODULATION DOUT SCLK KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 26

HF Multi-Protocol Transceiver IC ► Antenna design: 1. Define and create Antenna Loop PCB or wire wound Equivalent circuit 2. Measure the inductance of the Loop KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 27

HF Multi-Protocol Transceiver IC 3. Calculate the components intermediate inductor, for calculation only! KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 28

HF Multi-Protocol Transceiver IC 4. Add variable (fixed) capacitors for fine tuning: • low tolerance components should be used – COG or NPO type capacitors • when optimum capacitor values have been found, the variable capacitors can be removed, • plan the space for 2 fixed, fine tuning capacitors at Cres and Cmatch KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 29

HF Multi-Protocol Transceiver IC Very small and cheap products are available already! KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 30

HF Multi-Protocol Transceiver IC KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 31

HF Multi-Protocol Transceiver IC ► Resources – Reference Guide (11 -07 -21 -001) http: //www. ti. com/tiris – ISO/IEC 15693 Part 2/3 http: //www. iso. ch – ISO/IEC 14443 Part 2/3/4 http: //www. iso. ch – Antenna design notes http: //www. ti. com/tiris/docs/manuals/app. Notes/HFAntenna. Design. Notes. pdf KS/JAG 18 -NOV-03 Copyright Texas Instruments Page 32