U2407B Simple Controller for Fast Charge Systems Description The bipolar IC U2407B is a fast charge battery controller for drained NiCd/ NiMH batteries. Apart from phase control, it is identical with U2405B, but has four LED outputs. The IC enables the designer to create an efficient and economic charge system. The U2407B incorporates an intelligent multiple-gradient battery-voltage monitoring combined with temperature and failure mode detection. With automatic top-off charging, the integrated circuit ensures that the charge device stops regular charging before the critical stage of overcharging is achieved. It incorporates an additional algorithm for reactivating fully drained batteries especially after long time storage. It has four LED driver outputs for different indications of the charge status. Features Applications D D D D D D D D D Primary switch mode D AC/ DC wall plug adapter D Ultra fast charger (10 minutes) Multiple gradient monitoring Temperature window (Tmin/Tmax) Exact currentless measurement Four LED status outputs Linear power control Preferred for externally regulated current sources Preformation algorithm for drained batteries Package: DIP16/ SO16 Programmable top-off charge function 13 15 12 2 3 10 Oscillator VRef 6.5 V/10 mA Status control Scan path 16 11 Control unit Switch output Battery detection VRef = 5 V Gradient d2V/dt2 and –dV 9 Power - on control VBatt monitor 0.1 to 4 V 14 Power supply 160 mV Ref VS = 8 to 26 V 1 Temp. control Sensor Tmax 95 10648 4 5 6 7 Charge break output 8 Figure 1. Block diagram TELEFUNKEN Semiconductors Rev. A4, 05-Mar-97 1 (16) U2407B 10 W Input Voltage 8 V to 24 V C10 10 mF C1 R1 R7 1 kW R5 2.2 kW LED1 R4 2.2 kW LED2 BD649 Mounted on heatsink LED3 LED4 T1 BC237 R8 T2 D1 BYW52 100 kW RB1 1 kW Ich VS 10 GND 14 1 2 3 15 C2 0.22 mF 4 OPO U2407B CR 1 mF RB2 10 kW 220 mF 13 VBatt 9 C7 1 mF RB3 10 kW 6 7 16 Sensor Battery 12 R6 10 kW Rsh 0.2 W 5 C4 1 mF OPI VRef 8 11 tp STM Tmax Output Osc CO 10 nF RT2 100 kW RT3 1.5 kW RO 270 kW 95 10677 Figure 2. Scheme for DC linear regulation Pin Description Package: DIP16/ SO16 GND 1 16 Output LED2 2 15 LED4 LED3 3 14 VS OPO 4 13 VRef OPI 5 12 Osc Tmax 6 11 STM 10 LED1 Sensor 7 tp 9 8 95 10618 2 (16) VBatt Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Symbol Function GND Ground LED2 Display output “top-off/ trickle charge” LED3 Display output “Fast charge” OPO Operational amplifier output OPI Operational amplifier input Tmax Maximum temperature Sensor Temperature sensor tp Charge break output VBatt Battery voltage LED1 Display output “failure mode” STM. Test mode switch (status control) Osc Oscillator VRef Reference output voltage VS Supply voltage LED4 Display output “top-off charge” Output Trigger output TELEFUNKEN Semiconductors Rev. A3, 05-Mar-97 U2407B General Description The integrated circuit, U2407B, is designed for charging Nickel-Cadmium (NiCd) and Nickel-Metal-Hydride (NiMH) batteries. Fast charging results in voltage lobes when fully charged (figure 3). It supplies two identifications ( i. e., + d2V/dt2, and – DV) to end the charge operation at the proper time. * charge characteristics are present multiple gradient control results in very efficient switch-off. An additional temperature control input increases not only the performances of the charge switching characteristics but also prevents the general charging of a battery whose temperature is outside the specified window. * As compared to the existing charge concepts where the charge is terminated after voltage lobes according to – DV and temperature gradient identification, the U2407B takes into consideration the additional changes in positive charge curves, according to the second derivative of the voltage with respect to time (d2V/dt2). The charge identification is the sure method of switching off the fast charge before overcharging the battery. This helps to give the battery a long life by hindering any marked increase in cell pressure and temperature. A specific preformation algorithm is implemented for reactivating fully drained batteries especially in the case of batteries that have been stored for a long time. A constant charge current is necessary for continued charge-voltage characteristic. This constant current is generated from an external power supply and can be regulated with the help of an internal op-amp regulator (figure 2). An external current source can also be controlled by the switch output Pin 16 (see figure 12). Even in critical charge applications, such as a reduced charge current or with NiMH batteries where weaker For further information please refer to the applications. Battery insertion Battery voltage 5V Top-off charge stop Fast charge stop d 2V dt2 ) without charge control –DV preformation ÎÎ ÎÎ 1.6 V –DV ) ddtV , –DV 2 2 Fast charge rate IO I (RB1) 95 10616 Top-off charge rate 1/4 IO t1 = 5 min t2 = 20 min Trickle charge rate 1/256 IO t Figure 3. Charge function diagram, fosc = 800 Hz TELEFUNKEN Semiconductors Rev. A4, 05-Mar-97 3 (16) U2407B Flow Chart Explanation, fosc = 800 Hz (Figures 2, 3 and 4) Battery pack insertion disables the voltage lock at battery detection input Pin 9. All functions in the integrated circuit are reset. For further description, DIP-pinning is taken into consideration. Battery Insertion and –DV Monitoring After battery insertion fast charge Io begins when the input voltage VBatt is higher than 1.6 V. For the first 5 minutes the d2V/dt2-gradient recognition is suppressed, –DV monitoring is activated. In case the detected VBatt voltage is less then 1.6 V the special preformation procedure will be activated. The reference level with respect to the cell voltage can be adjusted by the resistor RB3 (see figure 2). Top-Off Charge Stage By charge disconnection through the + d2V/dt2 mode, the device switches automatically to a defined protective top-off charge with a pulse rate of 1/4 IO (pulse time, tp = 5.12 s, period, T = 20.48 s). The top-off charge time is specified for a time of 20 minutes @ 800 Hz. During top-off mode the LED4 is in ON mode. Trickle Charge Stage When top-off charge is terminated, the device switches automatically to trickle charge with 1/256 IO (tp = 5.12 s, period = 1310.72 s). The trickle continues until the battery pack is removed. During trickle mode the LED2 output is in on mode, LED4 is in OFF-mode. Preformation Procedure Before fast charge of fully drained or long-time stored batteries begins, a reactivation of it is necessary. The preformation current is dependent on pull-up resistor RB1. The fast charge starts only after the VBatt is higher than 1.6 V. During the first 10 minutes the green LED2 is blinking. If after 10 minutes, VBatt voltage has not reached the reference level, the indication changes to red blinking LED1. The charge will continue with preformation rate I (RB1). In case VBatt increases to 1.6 V reference level, the fast charge rate current, Io, is switched-on and the green LED2 is blinking. Basic Description Power Supply, Figure 2 The charge controller allows the direct power supply of 8 to 26 V at Pin 14. Internal regulation limits higher input voltages. Series resistance, R1, regulates the supply current, IS, to a maximum value of 25 mA. Series resistance is recommended to suppress the noise signal, even below 26 V limitation. It is calculated as follows. R 1min V w V25–26 mA R 1max vV –DV Cut-Off (Monitoring) When the signal at Pin 9 of the DA converter is 12 mV below the actual value, the comparator identifies it as a voltage drop of –DV. The validity of –DV cut-off is considered only if the actual value is below 12 mV for three consecutive cycles of measurement. d2V/dt2-Gradient If there is no charge stop within the first 5 minutes after battery insertion, then d2V/dt2 monitoring will be active. In this actual charge stage, all stop-charge criteria are active. max – 8 V I tot min where Itot = IS + IRB1 + I1 Vmax, Vmin = Rectified voltage IS = Current consumption (IC) without load IRB1 = Current through resistance, RB1 I1 = Trigger current at Pin 1 When close to the battery’s capacity limit, the battery voltage curve will typically rise. As soon as the +d2V/dt2 stop-charging criteria are met, the device will stop the fast charge activities. 4 (16) TELEFUNKEN Semiconductors Rev. A3, 05-Mar-97 U2407B Start Power on reset LED1,2,3,4 off yes *) 70 mV > VBatt > 5V no Batt. inserted *) Temp. range ok ? no yes Reset Charge stop no Temp. range ok ? LED1 blinking Preformation current I RB1 yes LED1 blinking LED3 blinking Fast charge begins yes no VBatt > 1.6 V yes tch > 10 min no Charge time t1 > 5 min ? VBatt 4 V no LED1 blinking LED3 off yes no no –dV switch off Batt. inserted *) –dV and d2V/dt2 monitoring activated yes yes yes no Batt temp range? yes no yes –dV disconnect LED1 blinking Batt. inserted *) no d2V/dt2 disconnect ? LED2 on LED2 on LED4 on Trickle charge 1/256 IO Top off charge 1/4 IO Batt. inserted *) yes no t2 > 20 min no no 95 10671 Figure 4. Flow chart TELEFUNKEN Semiconductors Rev. A4, 05-Mar-97 5 (16) U2407B Battery Voltage Measurement The battery voltage measurement at Pin 9 (ADCconverter) has a range of 0 V to 4 V, which means a battery pack containing two cells can be connected without a voltage divider. Value of the resistance, RB3 is calculated by assuming RB1 = 1 kW, RB2 = 10 kW, as follows: R B3 w 4 V) a safety If the AD converter is overloaded (VBatt switch-off occurs. The fast charge cycle is terminated by automatically changing to trickle charge. B2 V 10max V Bmax – V 10max The minimum supply voltage, Vsmin, is calculated for reset function after removing the inserted battery according to: Precaution should be taken that under specified charge current conditions, the final voltage at the input of the converter, Pin 9, should not exceed the threshold voltage level of the reset comparator, which is 5 V. When the battery is removed, the input (Pin 9) is terminated across the pulled-up resistance, RB1, to the value of 5 V-resetthreshold. In this way, the start of a new charge sequence is guaranteed when a battery is reinserted. V smin + 0.03mA @ R ǒR ) R RǓ ) 5V ǒR ) R ) R Ǔ B3 V9max VSmin VBmax B1 B2 B3 = Max voltage at Pin 9 = Min supply voltage at the IC (Pin 14) = Max battery voltage The voltage conditions mentioned above are measured during charge current break (switch-off condition). VS RB1 - dV Recognition – + VRef = 12 mV Ich RB2 Battery B2 B3 VDAC VB B1 where: If the battery voltage exceeds the converter range of 4 V, adjusting it by the external voltage divider resistance, RB2 and RB3 is recommended. 14 +R = DAC control comparator VDAC VBatt 9 – + V6 Rsh Reset comparator RB3 7V VRef = 4.3 V Reset 95 10623 – + VRef = 0.1 V Figure 5. Input configuration for the battery voltage measurement Table 1. valid when V10max = 3.5 V Cell No. VSmin (V) RB3 (kW) 6 (16) 1 8 – 2 8 – 3 8 51 4 9 16 5 11 10 6 13 7.5 7 15 5.6 8 17 4.7 9 19 3.9 10 21 3.3 11 23 3 12 25 2.7 TELEFUNKEN Semiconductors Rev. A3, 05-Mar-97 U2407B Analog-Digital-Converter (ADC), Test Sequence Plausibility for Charge Break A special analog-digital-converter consists of a five-bit coarse and a five-bit fine converter . It operates by a linear count method which can digitalize a battery voltage of 4 V at Pin 9 in 6.5 mV steps of sensitivity. – DV Cut-Off In a duty cycle, T, of 20.48 s, the converter executes the measurement from a standard oscillator frequency of fosc = 800 Hz. The voltage measurement is during the charge break time of 2.56 s (see figure 6), i.e., no-load voltage (or currentless phase). Therefore it has optimum measurement accuracy because all interferences are cut-off during this period (e.g., terminal resistances or dynamic load current fluctuations). After a delay of 1.28 s the actual measurement phase of 1.28 s follows. During this idle interval of cut-off conditions, battery voltage is stabilized and hence measurement is possible. An output pulse of 10 ms appears at Pin 8 during charge break after a delay of 40 ms. The output signal can be used in a variety of way, e.g., synchronising the test control (reference measurement). There are two criteria considered for charge break plausibility: When the signal at Pin 9 of the DA converter is 12 mV below the actual value, the comparator identifies it as a voltage drop of – DV. The validity of – DV cutt-off is considered only if the actual value is below 12 mV for three consective cycles of measurement. d2V/dt2 Cut-Off A four bit forward/ backward counter is used to register the slope change (d2V/dt2, VBatt – slope). This counter is clocked by each tracking phase of the fine AD-counter. Beginning from its initial value, the counter counts the first eight cycles in forward direction and the next eight cycles in reverse direction. At the end of 16 cycles, the actual value is compared with the initial value. If there is a difference of more than two LSB-bit (13.5 mV) from the actual counter value, then there is an identification of slope change which leads to normal charge cut-off. A second counter in the same configuration is operating in parallel with eight clock cycles delay, to reduce the total cut-off delay, from 16 test cycles to eight test cycles. 94 8693 Status Charge break Charge t 2.56 s T= 20.48 s charge break output 10 ms t 40 ms ADC conversion time (internal) 1.28 s 1.28 s t Figure 6. Operating sequence of voltage measurements TELEFUNKEN Semiconductors Rev. A4, 05-Mar-97 7 (16) U2407B Temperature Control, Figure 7 When the battery temperature is not inside the specified temperature windows, the overal temperature control will not allow the charge process. Sensor short circuit or interruption also leads to switch-off (faulty mode). A permanent switch-off follows after a measurement period of 20.48 s, if the temperature exceeds a specified level, which is denoted by a status of LED1. A charge sequence will start only when the specified window temperature range is attained. The temperature window is specified between two voltage transitions. The upper voltage transition is specified by the internal reference voltage of 4 V, and the lower voltage transition is represented by the external voltage divider resistances RT2 and RT3. NTC sensors are normally used to control the temperature of the battery pack. If the resistance values of NTC are known for maximum and minimum conditions of allowable temperature, then other resistance values, RT1, RT2 and RT3 are calculated as follows: suppose RT2 = 100 kW, then R T1 R T3 +R +R NTCmax NTCmin V Ref – 4V 4V R T2 R T1 If NTC sensors are not used, then select the circuit configuration according to figure 10. VRef VRef 13 RT2 Tmax 7 RT1 + – High temperature RT3 7V VRef = 4 V + – Sensor Low temperature 8 NTC sensor 7V 95 10622 Figure 7. Temperature window Current Regulation Charge Current Regulation, Figure 2 The charge concept requires a constant charge current supply outside of the circuit. This is achieved by an external switchable current source or by an internal error amplifier regulation of an externally situated power stage. According to figure 2 the operational amplifier (OpAmp) regulates the charge current, Ich (= 160 mV/ Rsh), average value. The OpAmp detects the voltage drop across the shunt resistor (Rsh) at input Pin 5 as an actual value. The actual value will then be compared with an internal reference value of 160 mV. 8 (16) TELEFUNKEN Semiconductors Rev. A3, 05-Mar-97 U2407B Status Control Different status control modes can be designed by four LED outputs. Status control regards the running charge cycle before it has been started and also after it has been terminated. LED1 OFF OFF OFF OFF Blinking LED2 OFF OFF ON ON OFF Failure mode: LED3 OFF Blinking OFF OFF OFF LED4 OFF OFF ON OFF OFF Status No battery (VBatt > 5 V) Fast charge Top-off charge Trickle charge Failure mode Temperature out of window, also before battery insertion or power-on. Battery break, short circuit, VBatt < 0.1 V To achieve custom specific display modes, several combinations between LED outputs 1 to 4 are recommended. (see applications) The blink frequency of LED outputs can be calculated as follows: f (LED) frequency, + Oscillator 1024 f osc Example 1: Display mode similar to U2402B and U2405B: LED1 red 10 LED2 (green) VS (LED1) (LED2/ LED3) OFF OFF VS OFF OFF Blinking Blinking ON OFF No battery (VBatt > 5 V) Fast charge Top-off, trickle charge All failure mode Status 1 kW green LED2 1 kW 2 Status LED1 (red) LED3 3 95 10672 Figure 8. Example 2: LED1 LED2 LED3 VS 10 red 1 kW 2 VS green 1 kW VS 3 LED1 (red) LED2 (green) (LED1/ LED3) (LED2) OFF OFF ON OFF Blinking OFF ON OFF No battery (VBatt > 5 V) Fast charge Top-off, trickle charge All failure mode 95 10673 Figure 9. TELEFUNKEN Semiconductors Rev. A4, 05-Mar-97 9 (16) U2407B Top-off Charge Rate Reduction Oscillator The current amplitude during top-off charge can be reduced as shown in figure 10. During top-off mode, both the LED4 output (Pin 15) and transistor T are on. The actual current amplitude is influenced with the help of resistor Rx, which is detected by the operational amplifier input OP1 (Pin 5). The decrease of the current flow depends on the reciprocal value of Rx. Time sequences regarding measured values and evaluation are determined by the system oscillator. All the technical data given in the description are with the standard frequency 800 Hz. 95 10674 LED4 VRef T 15 Oscillation Frequency Adjustment Rx OPI It is possibe to alter the frequency range in a certain limitation. Figure 11 shows the frequency versus resistance curves with different capacitance values. Recommendations: Battery 5 0.5C charge 0.5 500 Hz = 1C charge Rsh Figure 10. 250 Hz 500 Hz 2C charge 2 500 Hz = 1000 Hz 3C charge 3 500 Hz = 1500 Hz 10000 CO=2.2nF R O ( kW ) 1000 CO=10nF 100 CO=4.7nF 10 0.1 95 11408 10 1 fO ( kHz ) Figure 11. Frequency versus resistance for different capacitance values 10 (16) TELEFUNKEN Semiconductors Rev. A3, 05-Mar-97 U2407B Absolute Maximum Ratings Reference point Pin 2 (GND), unless otherwise specified Parameters Supply voltage Pin 14 Voltage limitation IS = 10 mA Current limitation Pin 14 t < 100 ms Voltages at different pins Pins 16, 2, 3, 10 and 15 Pins 11 up to 13, 4 up to 9 Currents at different pins Pin 1 Pins 3 up to 14 and 16 up to 18 Power dissipation Tamb = 60°C Ambient temperature range Junction temperature Storage temperature range Symbol VS Value 26 Unit V 31 IS Ptot Tamb Tj Tstg 25 100 26 7 25 10 650 – 10 to +85 125 – 40 to +125 mW °C °C °C Symbol RthJA Maximum 100 Unit K/W V I mA V mA Thermal Resistance Parameters Junction ambient Electrical Characteristics VS = 12 V, Tamb = 25°C, reference point Pin 1 (GND), unless otherwise specified Parameters Power supply Voltage range Power-on threshold Current consumption Reference Reference voltage Test Conditions / Pins Pin 14 ON OFF without load Symbol Min. VS VS 8 3.0 4.7 3.9 IS Typ. Max. Unit 26 3.8 5.7 9.1 V V V mA 6.71 6.77 10 V V mA mV/K Pin 13 IRef = 5 mA IRef = 10 mA Reference current Temperature coefficient Operational amplifier OP Output voltage range I5 = 0 Pin 4 Output current range V5 = 3.25 V Pin 4 Output pause current Pin 4 Non-inverting input voltage Pin 5 Non-inverting input current Pin 5 Comparator or temperature control Input current Pins 6 and 7 Input voltage range Pins 6 and 7 Threshold voltage Pin 7 Charge break output Pin 8 Output voltage High, I8 = 4 mA Low, I8 = 0 mA Output current V8 = 1 V TELEFUNKEN Semiconductors Rev. A4, 05-Mar-97 VRef 6.19 6.14 – IRef TC V4 ±I4 –Ipause V5 ±I5 6.5 6.5 – 0.7 0.15 80 100 0 ±I6, 7 V6, 7 V7 0 3.85 V8 8.4 5.8 5 0.5 0.5 5 4.15 100 I8 10 V mA mA V mA mA V V V mV mA 11 (16) U2407B Parameters Battery detection Analog-digital converter Test Conditions / Pins Pin 9 Conversion range Full scale level 0.1 V VBatt 4.5 V v v y5V Input current Input voltage for reset Input current for reset Min. VBatt 0 3.85 – IBatt VBatt IBatt VBatt Maximum voltage Maximum voltage Battery detection Hysteresis Mode select Treshold voltage Input current Input current Sync. oscillator Frequency Threshold voltage Symbol D VBatt Typ. 4.8 8 5.0 80 Vhys Max. Unit 4.0 V 0.5 5.3 35 mA 120 mV mV 15 V mA Pin 11 Testmode V11 I11 Normal mode Pin 11 open Pin 12 R = 150 kW, C = 10 nF High level Low level 4.7 20 0 fosc VT(H) VT(L) Input current 800 4.3 3% 2.2 3% I12 " " – 0.5 V mA Hz V 0.5 mA Applications 10 W R1 Input voltage 8 V to 26 V C1 RB1 1 kW C10 10 mF R2 2.2 kW R5 2.2 kW LED1 LED2 Controlled current source 100 mF VS GND 14 1 10 C2 0.22 mF 2 LED3 3 off LED4 on 13 VRef 4 OPO 15 U2407B Output 16 Ich RB2 10 kW VBatt 6 OPI Tmax 9 RB3 16 kW Battery 5 RT1 100 kW C7 4.7 mF Sensor R14 510 kW 7 12 8 11 tp STM Osc RO 270 kW CO 10 nF 95 10675 Figure 12. Minimum charge system with external current source 12 (16) TELEFUNKEN Semiconductors Rev. A3, 05-Mar-97 TELEFUNKEN Semiconductors Rev. A4, 05-Mar-97 14 VS LED3 LED1 LED2 9 8 1m F 11 10nF tp C4 S TM 1k W R9 CO 270k W OP I 5 Sensor V Batt OP O 4 3 R5 VS 2.2k W 10 2 green RO OSC T max LED4 U2407B V Ref OUTPUT GND 1 100 m F C1 7 12 6 15 13 16 C 10 10 m F 2.7k W R T3 100k W R T2 0.22 mF C2 V Ref Input voltage typ 12 V R 11 47k W R8 V Ref 1/2LM393 100k W ... 1M W Top off / trickle reduction 1mF C7 1mF CR 4.7 m F C3 red 1M W R4 Master 4 8 T1 Ic mounted on heatsink Ic T1 R7 1N4148 D2 10k W R6 10k W R A3 0.2 W R 12 V Ref T3 100k W 100k W V Ref BC212 10k W R6 10k W R A3 10k W 1N4148 D3 R A2 R 13 BC237 T2 BYW52 D1 R A2 R sh BC237 T2 BYW52 D1 BD649 10k W 1N4148 D3 BD649 1k W 10 W R7 10 W 1k W R1 R1 1mF C7 1m F CR 4.7 m F C3 red 100k W ... 1M W Top off / trickle reduction R 11 10k W R 10 47k W R8 V Ref + – 1/2LM393 1MW R4 Slave C4 5 7 9 4 3 1m F 1k W R9 10 2 green 2.2k W R5 VS VS 8 tp OP I Sensor V Batt OP O 1 V Ref OUTPUT GND 11 S TM OSC T max LED4 U2407B LED3 LED1 LED2 14 100 m F C1 12 6 15 13 16 12622 10nF CO 270k W RO 2.7k W R T3 100k W R T2 0.22 mF C2 V Ref U2407B Figure 13. Dual–slot charger 13 (16) U2407B Package Information Package DIP16 (CEI) Dimensions in mm 20.57 18.92 7.87 7.37 3.81 3.05 0.76 0.13 0.89 0.38 6.60 6.10 3.81 3.05 1.60 0.64 0.58 0.38 1.65 1.14 0.38 0.20 0.81 9.40 7.62 2.79 2.29 technical drawings according to DIN specifications 13014 Package DIP16 Dimensions in mm 7.82 7.42 20.0 max 4.8 max 6.4 max 0.5 min 3.3 1.64 1.44 Alternative 16 0.58 0.48 17.78 0.39 max 9.75 8.15 2.54 9 technical drawings according to DIN specifications 1 14 (16) 8 13015 TELEFUNKEN Semiconductors Rev. A3, 05-Mar-97 U2407B Package Information Package SO16 Dimensions in mm 5.2 4.8 10.0 9.85 3.7 1.4 0.25 0.10 0.4 1.27 6.15 5.85 8.89 16 0.2 3.8 9 technical drawings according to DIN specifications 1 TELEFUNKEN Semiconductors Rev. A4, 05-Mar-97 13036 8 15 (16) U2407B 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 16 (16) TELEFUNKEN Semiconductors Rev. A3, 05-Mar-97