NCD1025-IC - IXYS Corporationixapps.ixys.com/DataSheet/DATASHEET_NCD1025_IC.pdfNCD1025-IC is a read/write IC with on-silicon temperature sensor to be used in HDX contact-less RFID

http://www.ixys.es

NCD1025-IC 16 December 2013

Data sheet status: Preliminary Data

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NCD1025-IC HDX RFID IC WITH TEMPERATURE SENSOR

Preliminary data 2012 February 2012

http://www.ixys.es



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NCD1025-IC

HDX RFID IC WITH TEMPERATURE SENSOR

1 GENERAL DESCRIPTION

NCD1025-IC is a read/write IC with on-silicon temperature sensor to be used in HDX contact-less RFID devices for single transponder applications operating in the low frequency (134.2 kHz) range, supporting ISO 11784/85 standards.

NCD1025-IC contains 8 memory blocks of 33 bits each, based on field programmable, non-volatile EEPROM. Each block contains 32 data bits (bit 1 ... bit 32). Each of the blocks can be write protected through an associated lock bit, which is bit 0 of the corresponding block. Blocks 1 and 2 are referred to as the 64 bit identification data page 1 which is secured by an associated 16 bit CRC. Blocks 3, 4 and 6 are user configurable blocks. Blocks 0, 5 and 7 are reserved blocks which contain configuration parameters, as well as the option to irreversibly lock the RFID device.

NCD1025-IC receives requests from the reader (write, measure temperature, calibrate,…) as a pulse interval encoded, 100% amplitude modulated data signal.

Return data transmission from the transponder to the reader utilises FSK encoded modulation. This is achieved by a serial data stream controlled Frequency Shift Keying (FSK) of the transponder’s resonant circuit oscillation with an additional on-chip modulation capacitor between the transponder terminals HF and GND.

The passive transponder uses the supplied magnetic field to obtain the energy needed to send the 64-bit ID code and temperature data to the reader.

NCD1025-IC includes a temperature sensor. Temperature data are added at the end of the tag response frame, in such a way that the RFID can be used as a normal RFID (without temperature measurements) compatible with any ISO11785 reader, or as a temperature measurement RFID when used with customized readers.

NCD1025-IC temperature sensor is customized to cover a temperature range of 28 ºC centered on a temperature defined by calibration.

FEATURES

Air Interface: Contact-less, sequential power & data transmission (HDX)

Radio Frequency fc: 134.2 kHz typically

Reader Tag transmission: Pulse interval encoding (PIE) ~ 1 ... 2 kbit/s

Tag Reader transmission: FSK modulation, NRZ: ‘0’ ~ 134.2 kHz; ‘1’ ~ 124.2 kHz

Tag Reader data rate: RF/16 (~ 8 kbit/s)

On chip 16 bit CRC generator: Reverse CRC-CCITT as used in ISO/IEC 11785

On chip integrated CR trim capacitors: ~ 115 pF; split into 52, 26, 13, 6.5, 3, 1.5, 0.75 pF

On chip integrated modulation cap. C1: ~ 110 pF; fmod1 ~ 10 kHz with fc = 134.2 kHz

Identification data page: 64 bits data + associated 16 bits CRC

Temperature ranges: TCAL1 ±14 ºC, in the range from –20 ºC to 70_ºC, where TCAL1 is the first calibration temperature in a 2-point calibration procedure. The accuracy depends on the temperature calibration means used

http://www.incide-semi.com

COMPANY CONFIDENTIAL



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2 APPLICATION INFORMATION

NCD1025-IC is designed to be used in a complete RFID HDX tag with temperature measurement capabilities. The temperature sensor is integrated on-silicon, so that no extra external components are needed for temperature measurements. Only 1 inductor to operate as antenna and 2 external capacitors are needed for the RFID front-end and temperature sensor to operate.

Figure 1 shows the NCD1025-IC and the connections with the external components. ZAP and ZAP_SEL pins are used only for resonance frequency trimming, not for the final application. Typical values are:

L = 2.41 mH

CR = 470 pF (it is recommended to use a 470 pF ±2 % 50 V external SMD NP0 / C0G capacitor)

CL = 220 nF (it is recommended to use a ±5 % 10 V capacitor)

VDD

HF ZAP

ZAP_SEL

GND

CL CR L NCD1025

VDD

HF ZAP

ZAP_SEL

GND

CL CR L NCD1025

Figure 1: Application diagram

In a typical application, the NCD1025-IC will be placed on a board together with the 2 external capacitors building a module. This module will be soldered to the antenna and eventually encapsulated to provide mechanical protection, building the final RFID transponder.

The temperature of the RFID tag can be read with readers provided with a compatible protocol.

For accurate temperature reading the tag needs to be calibrated in temperature. Tags built using NCD1025-IC should be calibrated using 2 point calibration at 2 different temperatures TCAL1 and TCAL2. TCAL1 sets the center of the temperature measurement range, while TCAL2 sets the range where the accuracy is maximum. TCAL2 must be between the limits set by TCAL1 and TCAL1 + 14 ºC.

For most applications where an absolute accuracy of few tenths of degrees is acceptable, only both temperature calibration points TCAL1 and TCAL2, and a constant K which depends on TCAL1 and TCAL2 are need to calculate the temperature. IXYS San Sebastian will provide the right K value for each application. In this way, each reader whose temperature range (defined with TCAL1 and TCAL2) matches the temperature range of the sensor will provide a temperature reading with the accuracy mentioned above.

The tag sends to the reader some parameters from which the reader can extract the temperature information. These parameters are: a sign bit (SIGN), ND and NDCAL (see section 5.2.2). The reader can extract temperature data applying following equation:

a

NDcabbT

2

42





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Where:

bKc

TCAL

TCALKTCALKTCAL

NDCALb

TCAL

TCALKTCALKTCAL

TCAL

KTCALNDCAL

a

2

2

2

1

212

1

212

1

1

ND is signed depending on the value for bit SIGN (ND > 0 if SIGN = 0, ND < 0 if SIGN = 1)

Note that TCAL1, TCAL2, and K are “a priory” values stored in the reader.

3 PIN DESCRIPTION

Name Description

VDD Voltage supply GND Ground HF Oscillating signal ZAP_SEL Clock for the trimming ZAP Voltage for the trimming

Table 1: Pin description

4 FUNCTIONAL OVERVIEW AND DESCRIPTION

4.1 POWER TRANSFER

Power transfer to the tag is accomplished by magnetic coupling of the transponder and reader antenna. The reader and the transponder operate in a sequential mode with timely separated power and data transmission cycles. The RF operating field supplies power at the beginning of the request from the reader to the HDX transponder. During the charge (or powering phase) of between 15 and typically 50 ms the reader generates an electromagnetic field using a frequency of 134.2 kHz. The resonant circuit of the transponder is energised and the induced voltage is rectified by the integrated circuit to charge the capacitor CL. The transponder detects the end of the charge burst (EOB) and transmits its data using Frequency Shift Keying (FSK), utilising the energy stored in the capacitor CL. The charge phase is followed directly by the read phase.





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Figure 2: Charge and read phase - voltage at the reader’s exciter and transponder coil

4.2 COMMUNICATION SIGNAL INTERFACE - TAG TO READER

4.2.1 FREQUENCY

The tag shall be capable to communicate with the reader via an inductive coupling, whereby the power is switched off and the data are FSK modulated using the frequencies:

f0 = 134.2 kHz, for the data “Low Bit” encoding (ISO 11785 tolerance)

f1 = 124.2 kHz, for the data “High Bit” encoding (ISO 11785 tolerance)

f1 represents the frequency for data bit ‘1’ (Td1 = 16/f1) and f0 for the data bit ‘0’ (Td0 = 16/fc).

The low and high bits have different duration, because each bit takes 16 RF cycles to transmit. The high bit has a typical duration of ~ 130 µs, the low bit of ~ 120 µs. Figure 3 shows the FSK encoding principle used.





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Figure 3: FSK transmission used during the read phase

4.2.2 TRANSPONDER DATA RATE AND DATA CODING

The data coding is based on the NRZ method thus achieving an average data rate of ~ 8 kbit/s based on an equal distribution of ‘0’ and ‘1’ data bits.

4.3 COMMUNICATION SIGNAL INTERFACE - READER TO TAG

4.3.1 MODULATION

Communication between reader and transponder takes place using ASK modulation of the RF field with a modulation index of ~ 100%. The carrier frequency of the RF operating field is fC = 134.2 kHz.

4.3.2 READER DATA RATE AND DATA CODING

The reader to transponder communication uses Pulse Interval Coding (PIC). The reader creates pulses by switching the carrier on and off as described above. The modulation index of this amplitude modulation is 90_% to 100_%. The time between the falling edges of the pulses determines either the value of the data bit "0" and "1", a Code violation or a Stop (EOF) condition. T1 separates the single intervals. Its duration is T1 40·TC.





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TX ON

TX OFF

Data "0"

TX ON

TX OFF

Data "1"

TX ON

TX OFF

Codeviolation

T CV

T d1

T d0

T1

Figure 4: Reader to tag - Pulse Interval Coding modulation and encoding

Fast data rate Symbol

min nom max

Td0 42 Tc 47 Tc 52 Tc

Td1 62 Tc 67 Tc 72 Tc

TCVF/TCVS 175 Tc 180 Tc 185 Tc

Table 2: Reader - data coding times

NOTE: Tc =1/fc 7.452 µs

The default PIC threshold is configured for a medium data rate of 2.35 kBit/s, realised for example with a low bit period of Td0 = 350 µs and a high bit period of Td1 = 500 µs. The regenerated clock is available continuously during T1.

4.3.2.1 Start Of Frame and End Of Frame pattern

The reader request starts always with a Start of Frame (SOF) pattern. The SOF pattern as shown in Figure 5 consists the "Code violation" pattern TCVS which defines a clear start of frame.

Figure 5: Reader to tag – encoding of Start of Frame





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The End of Frame (EOF) condition of any reader request is defined as the rising edge of the RF field followed by a RF field activation time (Teoff) longer than the maximum Td1 value (72 clock cycles).

Figure 6: Reader to tag – encoding of End of Frame

4.3.3 WRITE PHASE AND THE PROGRAMMING OF DATA

A new identification number can be programmed into the OTP transponder in the following manner: After the charge phase, the transponder enters the write mode provided that the reader starts to modulate the field by switching the transmitter on and off. Writing means, the transponder shifts the received bits into an internal shift register. After the write phase the reader's transmitter is switched on for the EEPROM programming time in order to energise the process of programming the shift register’s data into the EEPROM. Each 33 data bits of a block – including the lock bit - are programmed simultaneously into the EEPROM. The EEPROM programming sequence includes an automatic read verification phase which makes sure that the data has been programmed securely thus ensuring satisfactory long term data retention. Once the data is programmed successfully into the EEPROM the transponder automatically sends back the captured data to the reader to allow another security check (Read-after-write comparison), this process takes place when the transmitter is switched off.

Figure 7: Charge, write and program - voltage at the reader and transponder antenna coil

As illustrated in Figure 7 the EEPROM programming sequence consists of:

Charge phase: Continuous reader (RF Module) transmitter output signal

Write phase: Pulse interval encoding of the reader’s transmitter output signal

Programming phase: Continuous RF transmitter output

Read phase: FSK modulation of the transponder‘s resonant circuit oscillation





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4.4 TEMPERATURE MEASUREMENT

4.4.1 TEMPERATURE SENSOR CALIBRATION

The tag with temperature measurement capabilities needs a 2-point calibration at two different temperatures. The calibration process is detailed below:

Run calibrate_temp1 command at TCAL1.

Run calibrate_temp2&lock command at TCAL2. TCAL2 must always be higher than TCAL1 but not higher than (TCAL1 + 14 ºC).

The sensor is calibrated. The temperature reading will be ok for those readers having TCAL1, TCAL2 and the corresponding K.

4.4.2 TEMPERATURE SENSOR OPERATION

There are 2 different modes of operation:

Temperature read by command: every time a command is sent by the reader, the temperature is measured while the field of the reader is on. The power consumption of the temperature does not imply a drop in the voltage supply of the tag. This operating mode is only possible with low quality coils which have enough bandwidth to send the reader-to-tag message, and therefore the operating distance is limited to few centimeters.

Temperature read with charge read only: The temperature sensor operates once the field of the reader is off, and the supply voltage of the tag is reduced due to the power consumption during sensor operation. This reduces the distance between tag and reader for a correct temperature measurement. This mode of operation enables a reading distance of several tenths of centimeters, depending on the size and type of both reader and tag antenna. In order to have accurate temperature measurement the tag frequency needs to be perfectly tuned or the temperature reading needs to be compensated for the actual resonant frequency of the tag.

5 TRANSMISSION PROTOCOL

The transmission protocol defines the mechanism to exchange requests and data between the reader and the transponder. The reader always starts the transmission, and the transponder does not start transmitting its response until the reader‘s RF field is turned off.

The different data exchanges that can happen between reader and transponder are summarized in the lines below:

The requests that can be performed by the NCD1025-IC transponder are as follows:

Charge Read Only

The content of page 1 is read without any specific page address by just charging (powering-up) the transponder during 50 ms. (ISO 11785 compatibility mode). The temperature data is added at the end of the frame (data not secured by CRC)

Read Page

Any of the pages can be addressed by sending the corresponding page address to the transponder. The 64 data bits of the page secured by 16 CRC bits are returned during the subsequent read phase. The temperature data is added at the end of the frame (data not secured by CRC)

Write Block

Following the command and the block address, the lock bit(s) and the 32 data bits to be programmed with the associated 16 CRC bits are sent to the transponder. The 32 data bits together with the associated lock





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bit are written into the specified block simultaneously. The transponder responds with the new contents of the block just programmed. Transponder response starts after the RF field is turned off. The temperature data is added at the end of the frame (data not secured by CRC)

Note: Each data block can be locked by setting the associated lock bit in order to create a read only access

and to disable further re-programming of this block.

Calibrate

These commands are used to calibrate the temperature sensor. As explained later, the sensor is thought to work with 2 points temperature calibration, so 2 different commands are needed. For each command, the value measured by the sensor is stored in the memory.

5.1 TEMPERATURE MEASUREMENT

Temperature measurement takes place each time the reader sends a Reader Request to the RFID. The tag answers always with the data according to the request received and with the current temperature measurement, which can be interpreted by a reader with a suitable protocol.

5.2 DATA FORMAT DEFINITIONS

5.2.1 READER COMMAND - REQUEST FORMAT

A Charge-Read Only request is generated by just charging the transponder: The demodulator must start working once the reader stops generating electromagnetic field. It counts the number of cycles while the electromagnetic field is low, if that number T1 is larger than 40·Tc, the tag will respond to a Charge-Read Only request.

If the T1 duration is not larger than 40·Tc, the system has to wait for a Reader Request Frame (RRF).

The Reader Request Format as sent by the reader is shown in Figure 8.

SOF COM ADR DATA CRC EOF 0 3 4 7 8 - LSB 39 40 - LSB 55

Figure 8: Reader Request Frame format

All signals are coded [MSB; LSB].

SOF – Start of Frame pattern

COM – Command [3; 0]

ADR – Address [3; 0]

DATA – Data (depending on the command) [31; 0]

CRC – ICRC (only if data bits are sent) [15; 0]

EOF – End of Frame pattern

The length of the frame varies with the different commands.

5.2.1.1 Command Table

The NCD1025-IC first evaluates the command byte which consists of an address field in the MSN (Most Significant Nibble) and a 4-bit command code of the incoming RRF according to Table 3. All other bit combinations may be considered as illegal.

ADDRESS COMMAND DESCRIPTION MSB LSB Read

0001 0001 Read Page 1: Block 1 (LSB) + Block 2 (MSB)








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Write

0000 0010 Write Block 0 – Management register

0001 0010 Write Block 1 – Identification Data/ LSB

0010 0010 Write Block 2 – Identification Data/ MSB

0011 0010 Write Block 3 – User defined Data

0100 0010 Write Block 4 – User defined Data

0101 0010 Write Block 5 – Temperature Calibration

0110 0010 Write Block 6 – Multi Purpose

0111 0010 Write Block 7 – Trimming Register

Write & Lock

0000 1010 Write & Lock Block 0 – Management register

0001 1010 Write & Lock Block 1 – Identification Data/ LSB

0010 1010 Write & Lock Block 2 – Identification Data/ MSB

0011 1010 Write & Lock Block 3 – Traceability Info/ LSB

0100 1010 Write & Lock Block 4 – Traceability Info/ MSB

0101 1010 Write & Lock Block 5 – Calibration

0110 1010 Write & Lock Block 6 – Multi Purpose

0111 1010 Write & Lock Block 7 – Configuration Register

Calibrate

0101 0100 Calibrate_temp1

0101 1100 Calibrate_temp1 & lock

0101 0101 Calibrate_temp2

0101 1101 Calibrate_temp2 & lock Table 3: RRF Commands in normal mode

5.2.2 TAG RESPONSE FRAME (TRF) FORMAT

Any RFID answer is framed as shown in Figure 9 and it has a fixed length of 117 bits. Depending on the type of answer the STOP and POST bits change.

START DATA CRC STOP POST 1 8 9 – LSB 72 73 - LSB 88 89-LSB 96 97-LSB 117

Figure 9 Tag Response Frame format

All the signals coded [MSB; LSB].

START – Start Byte [7; 0] := 7Ehex

DATA – Data [63; 0] := Data

CRC – DCRC [15; 0] := Data CRC

STOP – Stop Byte [7; 0] := ADDRESS + STATUS – for any other address and state cases

POST – Post Bits [20; 0]: := bit 0: SIGN (ND) 0: Positive 1:Negative

bit 1-10: ND (N1–SENSE)

bit 11-20: NDCAL (N1–N2)

According to ISO11785 norm, if the reader receives a signal from a RFID HDX within its range, it must wait 20 ms before sending the next read. The total frame duration in the worst case (only ‘1’s in the memory at 124 kHz) is 17.2 ms, resulting in a total time of 19.2 ms. This is the maximum frame length.

STOP Byte content answering a CRO and Read command

If the system receives a read command, the Data field includes the content of the required page starting by the LSB, and the CRC of such data is sent starting by the LSB. The Stop Byte reports the ADDRESS + STATUS of the read page. The Post Bits content the value of the sensor and calibration.

The information is coded according to Table 4. All other combinations can be considered not valid.





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ADDRESS STATUS DESCRIPTION MSB LSB

0001 0010 Read page 1 – page unlocked

0001 0110 Read page 1 – block 1 (LSB) locked + block 2 (MSB) unlocked

0001 1010 Read page 1 – block 1 (LSB) unlocked + block 2 (MSB) locked

0111 1110 Read page 1 – block 1 (LSB) locked + block 2 (MSB) locked + BIT16 ISO11785 = ‘0’

0001 1110 Read page 1 – block 1 (LSB) locked + block 2 (MSB) locked + BIT16 ISO11785 = ‘1’




0011 1110 Read page 2 – block 3 (LSB) locked + block 4 (MSB) locked




0101 1110 Read page 3 – block 5 (LSB) locked + block 6 (MSB) locked




0000 1110 Read page 4 – block 7 (LSB) locked + block 0 (MSB) locked Table 4 Answer about the state in a CRO or read command

STOP byte content answering a Write, Write&Lock, Calibrate, Calibrate&Lock command

If the system receives a Write, Write&Lock, Calibrate or Calibrate&Lock command, the Data field includes the content of the required block written twice. The Stop Byte contents the block address and the information related to the state.

The information of STOP byte for these commands is detailed in Table 5. All other combinations can be considered not valid.

ADDRESS STATUS DESCRIPTION MSB LSB

0000 0010 Write successful block 0 unlocked

0000 0110 Write&lock successful block 0

0000 1110 Write failed block 0 (locked)

0000 1010 Write failed block 0 (unreliable)



























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1111 1111 State “All blocks locked”

Table 5 Answer about the state in a Write or Write&Lock

The response of the calibration command is like a normal EEPROM writing command, the answer is the content of block 5 in the memory. The sensor measurement and calibration value are included in the answer.

5.3 CRC-CCITT ERROR CHECKING

The CRC error checking circuitry generates a 16 bits CRC to ensure the integrity of transmitted and received data packets. The reader and transponder use the CRC-CCITT (Consultative Committee for International Telegraph and Telephone) for error detection.

The 16 bits Write Frame BCC is generated by the transponder on reception of the complete write data stream to validate the correct data transmission.

During the Read Page protocol transmission the transponder has to generate the 16 bits Data BCC as checksum for the 64 bits identification data as well as the Read Frame BCC which allows to secure the complete data stream.

P (X) = X0 X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 X11 X12 X13 X14 X15

MSB

Data in

LSB

Figure 10: Schematic diagram of the 16 bits CRC-CCITT generator

The 16 bits cyclic redundancy code is calculated using the following polynomial with an initial value of 0000HEX:

P(X) = x16

+ x12

+ x5 + x

0

The implemented version of the CRC check has the following characteristics:

Reverse CRC-CCITT 16 as described in ISO/IEC 13239 and used in ISO/IEC 11784/11785

The CRC 16 bit shift register is initialized to all zeros at the beginning of a request

The incoming data bits are XOR-ed with the MSB of the CRC register and is shifted into the

register’s LSB

After all data bits have been processed, the CRC register contains the CRC-16 code.

Reversibility - The original data together with associated CRC, when fed back into the same CRC

generator will regenerate the initial value (all zero’s).

The temperature measurement data are not included in the CRC checking

6 MEMORY





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6.1 MEMORY BLOCK

The memory is structured into 8 Blocks of 32 bits each. In addition a Lock Bit is provided as Bit 0 corresponding to each Block. Two Blocks form one Page, of which 4 exist.

Block Address Page Address Description

0 4 Management Register/ MSB

1 Identification Data/ LSB

2 1

Identification Data/ MSB

3 User defined data/ LSB

4 2

User defined data / MSB

5 Temperature data/ LSB

6 3

Multipurpose/ MSB

7 4 Configuration Register/ LSB

Table 6: Memory organization

6.1.1.1 Page 1 – Identification Data

Page 1 is used for the Identification Data as specified in ISO/ IEC 11784. This page is locked if the Lock Bits of the corresponding Blocks are set to “1”. If the Page is locked, the stored value can not be overwritten.

6.1.1.2 Page 2 – User configurable page

Page 2 is user configurable. This Page is locked if the Lock Bits of the corresponding Blocks are set to “1”. If the Page is locked, the stored value can not be overwritten.

6.1.1.3 Page 3 – Temperature data

Page 3 contains the temperature related data. Block 6 in page 3 can be multipurpose.

Block 5 is the “calibration register” (CAREG). The calibration values (N1 and NDCAL) are stored in this block during the calibration process (detailed in section 4.4).

This Page is locked if the Lock Bits of the corresponding Blocks are set to “1”. If the Page is locked, the stored value can not be overwritten.

XX NDCAL(N1-N2) N1 LOCK 32 25 16 15 1 0

Figure 11 CAlibration REGister (CAREG) layout

6.1.1.4 Page 4 – Configuration Register + Management Register

Page 4 consists of Block 0, which is the Management Register, as the Most Significant Bits and the Block 7, which is the Configuration Register as the Least Significant Bits of it. A read of Page 4 returns Block 7 and Block 0. This Page is locked if the Lock Bits of the corresponding Blocks are set to “1”. If the Page is locked, the stored value can not be overwritten.

Configuration Register

The configuration register (CREG) layout is depicted in Figure 12.

If the flag DISCH is ‘1’ and the system is in ‘Normal Mode’, the storage capacitance is not going to be discharged.

The trimming bits specify the trimming vector for the capacitor in the analog part.

DISCH TRIM 2 TRIM 3 TRIM 4 LOCK 30 29 25 17 0

Figure 12 Configuration register (CREG) layout

TRIMx: Trimming bits

LOCK: Lock bit





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DISCH: Discharge (‘0’ discharge, ’1’ no discharge)

Management Register

The management register (MREG) contains information about the current state of the system.

XX MGM KEY LOCK 32 4 1 0

Figure 13 Management register (CREG) layout

LOCK: Lock bit

XX: Undefined

MGM KEY: Management key [3:0]

The contents of the Management key are explained in Table 7.

Key Value Description MSB LSB

0000 Normal Mode – by default

0110 All Blocks Locked Table 7 MGM content

Normal mode

In Normal mode all the commands previously mentioned are valid.

All blocks locked

Blocking MREG while the “Management key” has the 0110 value (“All Blocks Locked”) leads to the “All Blocks Locked state”. In this state the memory is writing protected and this is an irreversible state.

7 TRIMMING OF RESONANT CIRCUIT

The resonant circuit (LR, CR) connected between VCL and HF needs to be trimmed to the optimal system frequency (fC = 134.2 kHz) as the tolerances of the inductance and the external resonance capacitor could not be neglected. Especially for the charge function an accurate trimming is important because of the energy transfer to the charge capacitor CL is better.

The RF input (HF pin) has a certain input capacitance CIN with respect to GND, which is taken into consideration during definition of the resonant circuit components.

A capacitor array is provided at the RF input. The most significant of these trimming capacitors (CFUSE3, CFUSE2 and CFUSE1) are connected by default using polysilicon fuses, and can be programmed off (disconnected) by applying a fusing current. The current needed for fusing cannot be developed from the energy stored from the RF field, and therefore physical contact is needed. This has to be taken into account when defining the production steps.

The remaining capacitors of the array (CTRIM4, CTRIM3, CTRIM2, CTRIM1 and CTRIM0) are programmed off by default, and its state can be changed by programming the CREG register, as specified in 6.1.1.4.

PARAMETER Symbol CONDITION MIN NOM MAX Unit

Trimming Capacitor 0 CTRIM0 TAMB = +25 °C 0.65 0.77 0.89 pF





Trimming Capacitor 5 CFUSE1 TAMB = +25 °C 10.7 12.59 14.5 pF





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Capacitor Tolerance CT TAMB = +25 °C -10 0 +10 %

Table 8: Trimming capacitors

7.1 PROGRAMMING OF THE TRIM CAPACITORS

As explained above, the HDX OTP ASIC includes some fusing devices, which when correctly programmed allow changing the oscillating frequency of the RFID. The ASIC has 4 fuses, each of which can be fused independently. Nevertheless, in normal applications the fuses are grouped as follows: fuse1 (built by fuse1a and fuse1b), fuse2 and fuse3. Initially, when the fuse is not programmed, a capacitor of the value shown in Table 9 is connected to the resonant tank. Once the fuse is “programmed” the capacitor is disconnected.

fuse C [pF] Fuse1 52.36 Fuse2 26.18 Fuse3 12.59

Table 9:Added capacitance by each ”fusing” bit

Circuitry and interface suitable to perform the fusing of the polysilicon fuses is available on request.

During fusing process, the following pins must be connected:

- VDD: The RFID supply voltage must be 5 V.

- ZAP_SEL: A clock must be applied to this pin. The maximum frequency of the clock is 1 kHz and the amplitude must be 5 V, as the VDD value.

- ZAP: The only requisite is that the current compliance is at least 100 mA, while keeping a voltage higher than 6V at the ZAP pin.

The fusing sequence consists on generating 12 clock cycles in the input “CLK”; these clock cycles are divided in 4 groups of 3 cycles, during which the “VZAP” signal has to be ‘high’ if the fuse is to be fused, or ‘low’ if it is not. CLK frequency has to be lower than 1 kHz. Two examples of programming sequences are provided below in Figure 14 and Figure 15.

Figure 14 Sample sequence to program fuse1 and fuse3





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Figure 15: Sample sequence to program fuse2

8 SPECIFICATIONS

8.1 TEMPERATURE DATA

Parameter Value Unit Comment Temperature range after calibration

TCAL1 ± 14 ºC See calibration procedure

Temperature range with max. accuracy

TCAL1 – TCAL2 ºC

Resolution 0.02 ºC Non-uniform resolution; worst case Maximum error due to approximations

+0.3 ºC Worst case after calibration in the range from TCAL1 to TCAL2 when TCAL2 = TCAL1 + 10 ºC [1]

Sensitivity to deviations in frequency

160e-6 ºC/ppm For temperatures in the range from 20 ºC to 40 ºC [2]

Table 10: Temperature sensor characteristics

[1] Maximum error assuming that all sensors are calibrated exactly at TCAL1 and TCAL2 and assuming the calculated coefficients a, b and c are not truncated.

[2] Example: in the case of Temperature read by command operation, assuming a crystal oscillator in the reader with a frequency tolerance of 100 ppm, the corresponding temperature error is 160e-6x100=0.016ºC.

Apart from the errors mentioned above, some other errors are added due to the calibration process itself (temperature difference between calibrating unit and pattern thermometer due to gradient, error in pattern thermometer,…). These errors fully depend on the calibration procedure followed; the total error in temperature due to calibration errors is limited to the maximum calibration error at TCAL1 and TCAL2.

Example: calculate the temperature accuracy obtained with NCD1025-IC in following conditions:

Calibration process based on 2-point calibration inside water with a maximum error in temperature of 0.1 ºC, considering temperature gradient and pattern thermometer error.

Calibration is performed at TCAL1 = 30 ºC and TCAL2 = 40 ºC

Temperature is read using the Temperature read by command operation, with a reader having a crystal oscillator accuracy of 100 ppm

Coefficient a, b and c are not truncated in the reader

We want to calculate the maximum error obtained in the temperature range between 30 ºC and 40 ºC.

Maximum error due to approximations is 0.30 ºC.

Maximum error due to calibration is 0.1_ºC.

Maximum error due to frequency deviation in the reader is 0.016 ºC as shown above.

Total maximum error: 0.3 ºC + 0.1 ºC + 0.016 ºC = 0.416 ºC.





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8.2 MECHANICAL DATA

Limits Unit Parameter min typ max

Die thickness 470 m

8.3 ELECTRICAL DATA

8.3.1 OPERATING CONDITIONS

Limits Unit Parameter min max

Operating Temperature -25 +70 °C Storage Temperature -40 +100 °C

Limits Unit Conditions Parameter min typ max

HF limiter current 4 μA VHF = 5 V HF maximum voltage 12 V IHF = 10 mA Quiescent current consumption 5 μA VCL = 5.5 V Minimum HF capacitor 2 pF No trimming cap connected Maximum HF capacitor 117 pF All trimming caps connected Modulation capacitor 110 pF Endurance 100 k cycles Data retention 10 years

9 ORDERING INFORMATION

The dice are delivered sawn in waffle pack.

MPN Description Order code Package

NCD1025-UXXSXXXUN_ch

NCD1025-IC NCD1025-WXXSXXXUN_ch

Sawn die in waffle pack

10 OTHER INFORMATION

Temperature range, reading distance, temperature resolution and accuracy, … are parameters that can be customized to fulfil customer requirements. If you are interested in particular temperature ranges, accuracy, reading distance, please contact us for a customized analysis for your application.

NCD0125-IC based RFIDs are available in 32 mm glass transponder format under request. PC-based and hand-held readers ready to work with those are RFIDs are also available on request. If you are interested in a demo kit consisting on RFID tags + handheld reader, please contact us. If you are interested in any other tag format different from glass transponder, please contact us for a customized analysis for your application.

The temperature sensor concept (patent pending by IXYS SAN SEBASTIAN) can be applied to different kind of RFID standards (LF FDX, HF, UHF …). If you are interested in any other RFID standard, please contact us for a customized analysis for your application.





19/19

Level Data Sheet Status

[1]

Product Status [2][3]

Definitions

I Objective data Development This data sheet contains data for the objective specification for product development.

II Preliminary data

Qualification This data sheet contains data from the preliminary specification. Supplementary data will be updated at a later date

III Product data Production This data sheet contains data from the product specification

.

Disclaimers

LIFE SUPPORT- These products are not designed for use in life support appliances, devices, or systems where malfunction of these products can reasonably be expected to result in personal injury. IXYS San Sebastian customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify IXYS San Sebastian for any damages resulting from such an application.

RIGHT TO MAKE CHANGES- IXYS San Sebastian reserves the right to make changes in the products –including circuits, standard cells, and/or software- described or contained herein in order to improve design and/or performance. When the product is in full production (status ‘Production’), relevant changes will be communicated via a Customer Product/Process Change Notification (CPCN). IXYS San Sebastian assumes no responsibility or liability for the use of any of these products, conveys no license of title under any patent, copyright, or mask work right to these products, and makes no representations or warranties that these products are free from patent, copyright, or mask work right infringement, unless otherwise specified.

LIMITATION OF LIABILITY.- Liability of seller to buyer for damages for any cause whatsoever, and regardless of the form of any action, whether in contract or in tort, including, but not limited to negligence shall be limited to the price specified in the sale contract for the specific product or products that caused the damages or that are the subject matter of, or are directly or indirectly related to the cause of action. In no event shall seller be liable to buyer or others for loss of goodwill, loss of profits, loss of use or other special collateral, incidental or consequential damages, regardless of the form of action thereof, whether in contract or in tort, including but not limited to negligence, even if seller has been advised of the possibility of such damages or for any claim against buyer by any third party. Buyer assumes all liability for any and all damages arising from or in connection with, the use or misuse of the products by buyer, its employees, or others.

Contact information:

For additional information please contact

[email protected]

[1] Please consult the most recently issued data sheet before initiating or completing a design

[2] The product status of the device[s] described in this data sheet may have changed since this datasheet

was published. The latest information is available by contacting IXYS San Sebastian

[3] For data sheets describing multiple type numbers, the highest-level product status determines the data

sheet status.

Documents

NCD1025-IC - IXYS Corporationixapps.ixys.com/DataSheet/DATASHEET_NCD1025_IC.pdfNCD1025-IC is a read/write IC with on-silicon temperature sensor to be used in HDX contact-less RFID