U2270B
Read / Write Base Station IC
Description
IC for IDIC® *) read-write base stations The U2270B is a bipolar integrated circuit for read-write base stations in contactless identification and immobilizer systems. The IC incorporates the energy transfer circuit to supply the transponder. It consists of an on-chip power supply, an oscillator, and a coil driver optimized for automotivespecific distances. It also includes all signal-processing circuits which are necessary to form the small input signal into a microcontroller-compatible signal. The U2270B is well suitable to perform read operations with e5530-GT and TK5530-PP transponders and also performs read-write operations with TK5550-PP and TK5560-PP transponders.
Features
D D D D D D D D D
Carrier frequency fosc 100 KHz – 150 KHz Typical data rate up to 5 Kbaud at 125 KHz Suitable for Manchester and Bi-phase modulation Power supply from the car battery or from 5-V regulated voltage Optimized for car immobilizer applications Tuning capability Microcontroller-compatible interface Low power consumption in standby mode Power supply output for microcontroller
Applications
D Car immobilizers D Animal identification D Access control D Process control D Further industrial applications
Case: SO16 U2270B-FP
Transponder / TAG
Read / write base station
Transp. IC e5530 e5550 e5560
RF– Field typ. 125 kHz
Osc
Carrier enable
U2270B
NF read channel Data output
MCU
Unlock System
TK5530-PP e5530-GT TK5550-PP TK5560-PP Figure 1.
*)
9300
IDIC® stands for IDentification Integrated Circuit and is a trademark of TEMIC. 1 (13)
TELEFUNKEN Semiconductors Rev. A3, 13-Dec-96
U2270B
Pin Description
GND 1 Output OE Input MS CFE 2 3 4 5 6 16 HIPASS 15 RF 14 VS 13 Standby 12 VBatt 11 DVS 10 9
9844
Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Symbol GND Output OE Input MS CFE DGND COIL 2 COIL 1 VEXT DVS VBatt Standby VS RF HIPASS
Function Ground Data output Data output enable Data input Mode select coil 1: Common mode / Differential mode Carrier frequency enable Driver ground Coil driver 2 Coil driver 1 External power supply Driver supply voltage Battery voltage Standby input Internal power supply (5 V) Frequency adjustment DC decoupling
DGND 7 COIL2 8
Figure 2. Pinning
VEXT COIL1
Block Diagram
DVS VEXT VS VBatt
Standby Power supply COIL1
=1
MS CFE
COIL2 Driver DGND
&
Oscillator
Frequency adjustment
RF
Output Amplifier Input Low pass filter Schmitt trigger
9692
&
HIPASS
GND
OE
Figure 3.
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TELEFUNKEN Semiconductors Rev. A3, 13-Dec-96
U2270B
Functional Description
Power Supply (PS)
DVS VEXT VS V Batt Standby
internal supply
9V
25 kW
12 kW 6V
PS
6V
18 V
COILx
DRV
DGND
Figure 4. Equivalent circuit of power supply and antenna driver
11413
The U2270 can be operated with one external supply voltage or with two externally-stabilized supply voltages for an extended driver output voltage or from the 12-V battery voltage of a vehicle. The 12-V supply capability is achieved via the on-chip power supply (see figure 4). The power supply provides two different output voltages, VS and VEXT.
VS is the internal power supply voltage except for the driver circuit. Pin VS is used to connect a block capacitor. VS can be switched off by the pin STANDBY. In standby mode, the chip’s power consumption is very low. VEXT is the supply voltage of the antenna’s pre-driver. This voltage can also be used to operate external circuits, i.e., a microcontroller. In conjunction with an external NPN transistor, it also establishes the supply voltage of the antenna coil driver, DVS.
TELEFUNKEN Semiconductors Rev. A3, 13-Dec-96
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U2270B
The following section explains the 3 different operation modes to power the U2270B. 1. One-rail operation All internal circuits are operated from one 5-V power rail. (see figure 5). In this case, VS ,VEXT and DVS serve as inputs. VBatt is not used but should also be connected to that supply rail.
+5 V (stabilized)
3. Battery-voltage operation Using this operation mode, VS and VEXT are generated by the internal power supply. (refer to figure 7). For this mode, an external voltage regulator is not needed. The IC can be switched off via the pin Standby. VEXT supplies the base of an external NPN transistor and external circuits, i.e., a microcontroller (even in Standby mode). Pin VEXT and VBatt are overvoltage protected via internal Zener diodes (refer figure 4).The maximum current into that pins is determined by the maximum power dissipation and the maximum junction temperature of the IC. For a short-time current pulse, a higher power dissipation can be assumed (refer to application note ANT019).
7 to 16 V
DVS
VEXT
VS
VBatt Standby
12579
Figure 5.
2. Two-rail operation In that application, the driver voltage, DVS, and the pre-driver supply, VEXT, are operated at a higher voltage than the rest of the circuitry to obtain a higher driver-output swing and thus a higher magnetic field, refer to figure 6. VS is connected to a 5-V supply, whereas the driver voltages can be as high as 8 V. This operation mode is intended to be used in situations where an extended communication distance is required.
7 to 8 V (stabilized) 5 V (stabilized)
DVS
VEXT
VS
VBatt Standby
12600
Figure 7.
DVS
VEXT
VS
VBatt Standby
12580
Figure 6. Table 1. The following table summarizes the characteristics of the various operation modes.
Operation Mode 1. One-rail operation
ÁÁÁÁÁÁ Á Á Á Á Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁ Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
5 V ± 10% 2. Two-rail operation 3. Battery voltage operation 5 V ± 10% 7 V to 8 V 6 V to 16 V 6 V to 7 V No
External Components Required 1 Voltage regulator 1 Capacitor 2 Voltage regulators 2 Capacitors 1 Transistor 2 Capacitors Optional for load-dump protection: 1 Resistor 1 Capacitor
Supply Voltage Range
Driver Output Voltage Swing 4V
[
Standby Mode Available No
[4V
Yes
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U2270B
Oscillator (Osc)
The frequency of the on-chip oscillator is controlled by a current fed into the RF input. An integrated compensation circuit ensures a widly temperature and supply voltage independent frequency which is selected by a fixed resistor between RF (pin 15) and VS (pin 14). For 125 kHz a resistor value of 110 kW is defined. For other frequencies, use the following formula: Rf
RS 10 kW CIN 210 kW VBias – 0.4 V VBias
12601
VBias + 0.4 V
~ ~
+ f14375 [kHz]
0
– 5 kW
This input can be used to adjust the frequency close to the resonance of the antenna. For more details refer to the applicatons and the application note ANT019.
VCC
Figure 9. Equivalent circuit of Pin Input
Amplifier (AMP)
Rf
2 kW RF
The differential amplifier has a fixed gain, typically 30. The HIPASS pin is used for dc decoupling. The lower cut–off frequency of the decoupling circuit can be calculated as follows: f cut
9695
+2
p
1 C HP
Ri
Figure 8. Equivalent circuit of Pin RF
The value of the internal resistor Ri can be assumed to be 2.5 kW. Recommended values of CHP for selected data rates can be found in the chapter “Applications”.
R + – Schmitt trigger
Filter (LPF)
The fully-integrated low-pass filter (4th order butterworth) removes the remaining carrier signal and high-frequency disturbancies after demodulation. The upper cut-off frequency of the LPF depends on the selected oscillator frequency. The typ. value is fosc/18. That means that data rates up to fosc/25 are possible if Bi-phase or Manchester encoding is used. A high-pass characteristic results from the capacitive coupling at the input Pin 4, as shown in figure 9. The input voltage swing is limited to 2 Vpp. For frequency response calculation, the impedances of the signal source and LPF input (typ. 220 kW) have to be considered. The recommended values of the input capacitor for selected data rates are shown in the chapter “Applications”. Note: After switching on the carrier, the dc voltage of the coupling capacitor changes rapidly. When the antenna voltage is stable, the LPF needs approximately 2 ms to recover full sensitivity.
R LPF VRef
R Ri
R
HIPASS CHP
12578
Figure 10. Equivalent circuit of pin HIPASS
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U2270B
Schmitt Trigger
The signal is processed by a Schmitt trigger to suppress possible noise and to make the signal mC compatible. The hysteresis level is 100 mV symmetrically to the dc operation point. The open-collector output is enabled by a low level at OE (Pin 3).
30 mA
7 mA
MS
12603
OE
12602
Figure 12. Equivalent circuit of Pin MS
Figure 11. Equivalent circuit of Pin OE
Driver (DRV)
The driver supplies the antenna coil with the appropriate energy. The circuit consists of two independant output stages. These output stages can be operated in two different modes. In common mode, the outputs of the stages are in phase. In this mode, the outputs can be interconnected, to achieve a high current output capability. Using the differential mode, the output voltages are in anti-phase. Thus, the antenna coil is driven with a higher voltage. For a specific magnetic field, the antenna coil impedance is higher for the differential mode. As a higher coil impedance results in a better system sensitivity, the differential mode should be preferred. The CFE input is intended to be used for writing data into a read/write or a crypto transponder. This is achieved by interrupting the RF field with short gaps. The TEMIC write method is described in the data sheets of TK5550 and TK5560. The various functions are controlled by the inputs MS and CFE, refer to function table. The equivalent circuit of the driver is shown in figure 4.
30 mA
CFE
12604
Figure 13. Equivalent circuit of Pin CFE
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U2270B
Function Table
ÁÁÁÁÁÁÁÁÁ Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á ÁÁÁÁÁÁÁÁÁ Á Á ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁ Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁ Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á ÁÁÁÁÁÁÁÁÁ Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á ÁÁÁÁÁÁÁÁÁ Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á
High High OE Low High Output Enabled Disabled Standby Low High U2270B Standby mode Active
CFE Low Low High
MS Low High Low
COIL1 High Low
COIL2 High High
Applications
To achieve the suitable application, consider the power supply environment and the magnetic coupling situation. The selection of the appropriate power supply operation mode depends on the supply environment. If an unregulated supply voltage in the range of V = 7 V to 16 V is available, the internal power supply of the U2270B can be used. In this case, the standby mode can be used and an external low-current µC can be supplied. If a 5-V supply rail is available, it can be used to power the U2270B. In this case please check that the voltage is noise-free. An external power transistor is not necessary. The application depends also on the magnetic coupling situation. The coupling factor mainly depends on the transmission distance and the antenna coils. The following table lists the appropriate application for a given coupling factor. The magnetic coupling factor can be determined using the TEMIC test transponder coil.
The maximum transmission distance is also influenced by the accuracy of the antenna’s resonance. Therefore, the recommendations given above are proposals only. A good compromise for the resonance accuracy of the antenna is a value in the range of fres = 125 kHz ± 3%. Further details concerning the adequate application and the antenna design is provided in the TEMIC application note ANT019 and in the TEMIC article “Antenna Design Hints”. The application of the U2270B includes the two capacitors CIN and CHP whose values are linearly dependend on the transponder’s data rate. The following table gives the appropriate values for the most common data rates. The values are valid for Manchester and Bi-phase code. Data Rate f = 125 kHz f/32 = 3.9 kbit/s f/64 = 1.95 kbit/s Input Capacitor (CIN) 680 pF 1.2 nF Decoupling Capacitor (CHP) 100 nF 220 nF
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á ÁÁÁÁÁÁÁÁÁ Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁ Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ ÁÁÁÁÁÁÁÁÁÁÁ Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ Á Á
Magnetic Coupling Factor k > 3% k > 1% Appropriate Application Free-running oscillator Diode feedback k > 0.5% k > 0.3% Diode feedback plus frequency altering Diode feedback plus fine frequency tuning The following applications are typical examples. The values of CIN and CHP correspond to the transponder’s data rate only. The arrangement to fit the magnetic coupling situation is also independent from other design issues exept of one constellation. This constellation, consisting of diode feedback plus fine frequency tuning together with the two-rail power supply should be used if the transmission distance is in the range of d 10 cm.
[
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U2270B
Application 1
Application using few external components. This application is for intense magnetic coupling only.
9693
110 kW 5V VBatt 47 nF 47 mF DVS
VEXT
VS
VDD
U2270B
RF MS
INPUT CIN
CFE OE STANDBY OUTPUT HIPASS
1N4148
Microcontroller
CHP
470 kW 1.5 nF R
1.35 mH
COIL1
COIL2 1.2 nF DGND GND VSS
Figure 14.
Application 2
Basic application using diode feedback. This application permits higher communication distances than application 1.
12605
BC639 4x 1N4148 68 kW 22 mF 22 mF
360 W
12 V
GND 22 mF
75 kW 100 kW 1.2 nF 82 W
4.7 nF 43 kW
VS VEXT DVS VBatt RF COIL 2 MS CFE
VDD
1.35 mH Antenna 1N4148 470 kW
U2270B
COIL 1 Input HIPASS DGND GND Standby Output OE I/O
Microcontroller
CIN 1.5 nF CHP
VSS
Figure 15.
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U2270B
Application 3
This application is comparable to application 2 but alters the operating frequency. This permits higher antenna resonance tolerances and/or higher communication
4x 1N4148 68 kW 22 mF 5V 47 nF
distances. This application is preferred if the detecting µC is close to the U2270B as an additional µC signal controls the adequate operating frequency.
75 kW 100 kW 1 nF
4.7 nF 43 kW
VS RF COIL 2
VEXT
DVS VBatt MS CFE
VDD
GND
1.5 mH Antenna
82 W
U2270B
COIL 1 Input HIPASS 1.5 nF 4.7 kW 1.5 kW CHP DGND GND Standby Output OE
Microcontroller
1N4148 180 pF 100 W BC846 470 kW
CIN
VSS
12606
Figure 16.
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U2270B
Absolute Maximum Ratings
All voltages are referred to GND (Pins 1 and 7). Parameters/Conditions Pin Operating voltage Pin 12 Operating voltage Pins 8, 9, 10, 11 and 14 Symbol VBatt VS, VEXT, DVS, Coil 1, Coil 2 Min. VS –0.3 Typ. Max. 16 8 Unit V V
Range of input and output voltages Pins 3, 4, 5, 6, 15 and 16 Pins 2 and 13 Output current Pin 10 Output current Pin 2 Driver output current Pins 8 and 9 Power dissipation SO16 Junction temperature Storage temperature Ambient temperature
–0.3 –0.3 IEXT IOUT ICoil Ptot Tj Tstg Tamb
–55 –40
VS+0.3 VBatt 10 10 200 380 150 125 105
V mA mA mA mW °C °C °C
Thermal Resistance
Parameters/Conditions Pin Thermal resistance SO16 Symbol RthJA Min. Typ. Max. 120 Unit K/W
Operating Range
All voltages are referred to GND (Pins 1 and 7) Parameters/Conditions Pin Operating voltage Pin 12 Operating voltage Pin 14 Operating voltage Pin 10 Pin 11 Carrier frequency Symbol VBatt VS VEXT DVS fosc Min. 7 4.5 4.5 100 Typ. 12 5.4 Max. 16 6.3 8 150 Unit V V
125
kHz
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U2270B
Electrical Characteristics
Test conditions (unless otherwise specified): VBatt = 12 V, Tamb = –40 to 105_C Parameters Data output – collector emitter saturation voltage Data output enable – low level input voltage – high level input voltage Data input – clamping level low – clamping level high – input resistance – input sensitivity Driver polarity mode – low level input voltage – high level input voltage Carrier frequency enable – low level input voltage – high level input voltage Operating current Test Conditions / Pins Pin 2 Iout = 5 mA Pin 3 Vil Vih Pin 4 Vil Vih Rin f = 3 kHz (squarewave) gain capacitor = 100 nF Pin 5 Vil Vih Pin 6 Vil Vih IS 0.8 3.0 4.5 9 V V mA 10 2 3.8 220 V V kW mV pp 0.2 2.4 V V 0.5 2.4 V V Symbol VCEsat Min. Typ. Max. 400 Unit mV
Standby current VS – Supply voltage – Supply voltage drift – Output current Driver output voltage – One rail operation – Battery voltage operation Vext – Output voltage – Supply voltage drift – Output current – Standby output current Standby input – low level input voltage – high level input voltage Oscillator – Carrier frequency Low pass filter – Cut off frequency Amplifier – Gain Schmitt trigger – Hysteresis voltage
Pin10, 11, 12 and 14 5 V application without load connected to the coil driver Pin 12 12 V application Pin 14
ISt VS dVs/dT IS 4.6 1.8 2.9 3.1 4.6 3.5 0.4
30
70
mA
V mV/K mA VPP VPP V mV/K mA mA V V kHz kHz
5.4 4.2 3.5 3.6 4.0 5.4 4.2
6.3
IL = ±100 mA VS, VEXT, VBatt, DVS = 5 V VBatt = 12 V Pins 8 and 9 Pin 10 IC active standby mode Pin 13 RF-resistor = 110 kW (application 2), REM 1. Carrier freq. = 125 kHz CHP = 100 nF
VDRV VDRV VEXT dVEXT/dT IEXT IEXT Vil Vih f0 fcut
4.3 4.7 6.3
0.8 3.1 121 125 7 30 100 129
mV
REM 1.: In application 1. where the oscillator operates in the free running mode, the IC must be soldered free from distortion. Otherwise, the oscillator frequency may be out of bounds.
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U2270B
Dimensions in mm
Package: SO16
94 8875
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TELEFUNKEN Semiconductors Rev. A3, 13-Dec-96
U2270B
Ozone Depleting Substances Policy Statement
It is the policy of TEMIC TELEFUNKEN microelectronic GmbH to 1. Meet all present and future national and international statutory requirements. 2. Regularly and continuously improve the performance of our products, processes, distribution and operating systems with respect to their impact on the health and safety of our employees and the public, as well as their impact on the environment. It is particular concern to control or eliminate releases of those substances into the atmosphere which are known as ozone depleting substances ( ODSs). The Montreal Protocol ( 1987) and its London Amendments ( 1990) intend to severely restrict the use of ODSs and forbid their use within the next ten years. Various national and international initiatives are pressing for an earlier ban on these substances. TEMIC TELEFUNKEN microelectronic GmbH semiconductor division has been able to use its policy of continuous improvements to eliminate the use of ODSs listed in the following documents. 1. Annex A, B and list of transitional substances of the Montreal Protocol and the London Amendments respectively 2 . Class I and II ozone depleting substances in the Clean Air Act Amendments of 1990 by the Environmental Protection Agency ( EPA) in the USA 3. Council Decision 88/540/EEC and 91/690/EEC Annex A, B and C ( transitional substances ) respectively. TEMIC can certify that our semiconductors are not manufactured with ozone depleting substances and do not contain such substances.
We reserve the right to make changes to improve technical design and may do so without further notice. Parameters can vary in different applications. All operating parameters must be validated for each customer application by the customer. Should the buyer use TEMIC products for any unintended or unauthorized application, the buyer shall indemnify TEMIC against all claims, costs, damages, and expenses, arising out of, directly or indirectly, any claim of personal damage, injury or death associated with such unintended or unauthorized use. TEMIC TELEFUNKEN microelectronic GmbH, P.O.B. 3535, D-74025 Heilbronn, Germany Telephone: 49 ( 0 ) 7131 67 2831, Fax number: 49 ( 0 ) 7131 67 2423
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