U243B TEMIC | Alldatasheet

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Technical content

Features

/C0068Can be protected against damage or interference with a minimum of external circuitry /C0068Temperature- and voltage-compensated frequency /C0068Warning indication of lamp failure by means of frequency doubling /C0068V oltage dependence of the car indicator lamps also compensated for lamp failure /C0068Relay output with high-current carrying capacity and low saturation voltage Figure 1. Application circuit as a car flasher

Rev. A1, 05-Sep-96 Preliminary Information 2 (6) Circuit Description The application circuit shows the operation of the U243B as a car-direction indicator signal generator. The flashing frequency is determined by the components R t and Ct, and the frequency can be calculated from f1 /C00251 R t /C0032 Ct /C0032 1.5 (Hz) where f1 is the frequency in normal flashing operation (basic frequency). The control frequency f2 is typically 2.2 times the value of f1 and is the frequency in the case of lamp failure. The bright periods for f1 and f2 are inter- nally set in the IC and are 50% for f1 and 40% for f2. The resistors R1 and R2 are needed to protect the circuit against possible damage. An integrated Z-diode in addi- tion to these external resistors limits the impulse current in the integrated circuit to ≤ 1.5 A. Connecting the circuit with the wrong polarity leads to current limitation by R R 2 and the resistance of the coil of the relay. A current of about 150 mA would then flow over R1, so that for unlim- ited protection against continuous reversal of the polarity of the supply, a 2-W resistor would be necessary. A short circuit between the indicator lamp (49a) and ground (31) can give rise to a voltage drop of about 4 V across the measuring resistance, R 3. The circuit is not damaged by such a short circuit. The use of this application circuit ensures damage and interference protection accordance to VDE 0839. The recognition point for lamp failure can be calculated from the control signal threshold, typically 81 mV with V S = 12 V . With 81 mV and a measuring resistance of R3 = 30 m/C0087, it corresponds to a lamp current of 2.7 A, i.e., the frequency change-over with a lamp load of 21 W + 11.4 W. The variation of the control-signal threshold with the supply voltage takes into account the PTC char- acteristic of the filament lamps. A resistance R p ≥ 5 k/C0087 between the lamp indicator (49a) and ground (31) ensures that in case the direction indicator switch is open, the flashing generator is in stand-by mode. With a control lamp of max. 4 W between 49 and 49a the IC still starts with the bright phase. The arrangement of the supply connections to Pins 2 and 6 must be such as to ensure that, on the connection PCB, the resistance of V S to Pin 6 is lower than that to Pin 2. Defined operation is ensured with a lamp load of PL /C0025 10 W or more. Defined operation with lamp loads ≥ 2 W require an additional external resistance as described in “Applications”. With considerably reduced external circuitry, the integrated circuit U243B can be used as an instable multivibrator in the frequency range f = 0.05 to 10 Hz. Absolute Maximum Ratings Reference point Pin 1 Parameters Symbol Value Unit Supply voltage Pins 2 and 6 V S 16.5 V Surge forward current tp = 0.1 ms Pins 2 and 6 IFSM 1.5 A tp = 2 ms Pins 2 and 6 IFSM 1.0 A tp = 2 ms Pin 8 IFSM 50 mA Output current Pin 3 Io 0.3 A Power dissipation Tamb = 95°C DIP8 Ptot 420 mW SO8 Ptot 340 mW Tamb = 60°C DIP8 Ptot 690 mW SO8 Ptot 560 mW Junction temperature Tj 150 °C Ambient temperature range Tamb –40 to +95 °C Storage temperature range Tstg –55 to +125 °C

Rev. A1, 05-Sep-96 3 (6)

Electrical Characteristics

Typical values under normal operation in application circuit figure 1, VS (+49, Pins 2 and 6) = 12 V Reference point ground (–31), Tamb = 25°C, unless otherwise specified Parameters Test Conditions / Pin Symbol Min Typ Max Unit Supply voltage range Pins 2 and 6 V S (+49) 9 ... 15 V Supply current, dark phase or stand-by Pins 2 and 6 IS 4.5 8 mA Supply current, bright phase Pins 2 and 6 IS 7.0 11 mA Z–diode limitation IS2, 6 = 70 mA Pins 2 and 6 V S 23 V Relay output, saturation voltage I0 = 150 mA, VS = 9 V Pin 3 V O 1.0 V Relay output, reverse current Pin 3 IO 0.1 mA Relay coil resistance R L 60 /C0087 Start delay (first bright phase) ton 10 ms Frequency-determining resistor R t 6.8 510 k/C0087 Frequency-determining capacitor C t 47 /C0109F Frequency tolerance (normal flashing, basic frequency f1 not including the tolerance of the external compo- nents R1 and Ct) Δf1 –5 +5 % Bright period (basic frequency f1) Δf1 47 53 % Bright period (control frequency f2) Δf2 37 45 % Frequency increase (lamp failure) f2 2.15 f1 2.3f1 Control-signal threshold V S = 15 V Pin 7 V R3 85 91 97 mV V S = 9 V Pin 7 V R3 66 71 76 mV V S = 12 V Pin 7 V R3 76 81 87 mV Transfer resistance 49a to common for stand-by R P 2 5 k/C0087 Lamp load PL 10 W

Applications

/C0068Flashing generator, operation with smaller loads (≥ 2 W) By adding a resistor to the application circuit (figure 1), defined operation with lamp loads ≥ 2 W is possible. The voltage drop across the resistor R4 is generated by the current flowing over the relay and should be about 15 mV . With a relay current of 150 mA (relay resistance 73 Q), this requires a resistance of R 4 = 100 m/C0087. The change of the operating point by 15 mV results in a corresponding change of the control signal threshold by 15 mV . For a lamp current of 2.7 A, a measuring resistance of R 3 = 81 mV – 15 mV 2.7 A = 25 m/C0087 results.

lines in the figure), e.g., to reduce the “bright”-time. Figure 2. Flashing generator with small loads Figure 3. Instable multivibrator for general-purpose applications

1 IC ground

2 Supply voltage VS

3 Relay driver

4 C t oscillator

5 R t oscillator

6 Supply voltage VS

7 Lamp-failure detection

8 Start input (49a)

Rev. A1, 05-Sep-96 5 (6) Dimensions in mm

Rev. A1, 05-Sep-96 Preliminary Information 6 (6) 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