L9686D

L9686 AUTOMOTIVE DIRECTION INDICATOR ADVANCE DATA RELAY DRIVER IN CAR DIRECTION INDICATORS FLASH FREQUENCY DOUBLES TO INDICATE LAMP FAILURE DUMP PROTECTION ( ± 80 V) REVERSE BATTERY PROTECTION DESCRIPTION The L9686 is a two frequency oscillator particularly suitable as relay driver for flashing light control in automotive applications. The circuit may be also used for other warning lamps like ”handbrake on” etc. The lamp failure detection is given by doubling the flash repetition frequency. The L9686 is supplied in minidip 8-lead and SO8 plastic packages. BLOCK DIAGRAM MINIDIP SO8 ORDERING NUMBERS: L9686 L9686D May 1995 1/7 This is advanced information on a new product now in development or undergoing evaluation. Details are subject to change without notice. L9686 PIN CONNECTION (Top view) DEVICE GND +VBATT OUTPUT OSCILLATOR 1 2 3 4 D95AT175 8 7 6 5 STARTER FAULT DET. N.C. OSCILLATOR ABSOLUTE MAXIMUM RATINGS Symbol VS Parameter Transient Peak Supply Voltage (R3 > 220Ω): Load Dump: 5ms < trise < 10ms τf Fall Time Constant = 100ms Rsource > 0.5Ω Field Decay: 5ms < tfall < 10ms, Rsource > Ω τr Rise Time Constant = 33ms Low Energy Spike: trise = 1µs, tfall = 2ms, Rsource > 10Ω Junction and Storage Temperature Range Value 80 Unit V – 80 ± 100 – 55 to 150 V V °C Tj, Tstg THERMAL DATA Symbol Rth j-amb Parameter Thermal Resistance Junction-ambient Max. SO8 180 Minidip 100 Unit °C/W 2/7 L9686 ELECTRICAL CHARACTERISTICS (– 20°C < Tamb than this threshold, the relay will be on and the voltage across the circuit will maintain constant increasing the current in the protective resistor R3. This is the maximum value for operation. This value must be higher than 1 K Ohms in order to limit the current in pin 8 during dumps. A recommended value for application should be 1,5 K Ohms. The external leakage from the blinker unit to ground must be with an equivalent resistor higher than 5,6 K Ohms to avoid parasitic operation when the switch S1 is off. This temperature coefficient is usefull to compensate the drift of the external timing network (R1, C1). This threshold is calculated for a 20 m Ohm shunt. The threshold is dependant of Vbat as the bulb current. FUNCTIONAL DESCRIPTION The circuit is designed to drive the direction indicator flasher relay. The application circuit shows the typical system configuration with the external components. Its consists of a network (R1 C1) to determine the oscillator frequency, shunt resistor (RS) to detect defective bulbs and two current limiting resistors (R2/R3) to protect the IC against load dump transients. The lightbulbs L2, L3, L4, L5, are the turn signal indicators with the dashboard-light L6. The S1 switch position is sensed across resistor R2 and Rlamp by input 8. The flashing cycle is started by closing S1 : then, after a delay time t d typically equal to 1.5 ms, the relay is actuated and the pin 3 goes high switching on the corresponding lamps L2, L3, (or L4, L5). These lamps will flash at the oscillator frequency not depending on the battery voltage value (8 - 18 V). The flashing cycle stops and the circuit is reset to the initial position when the switch S1 is open. The lamp failure detection function senses the current through the shunt resistor RS. When one of the lightbulbs is defective the voltage drop across RS is reduced to a half and the failure is indicated by doubling the flashing frequency. 3/7 L9686 Figure 1: Application Circuit. 4/7 L9686 MINIDIP PACKAGE MECHANICAL DATA DIM. MIN. A a1 B b b1 D E e e3 e4 F I L Z 3.18 7.95 2.54 7.62 7.62 6.6 5.08 3.81 1.52 0.125 0.51 1.15 0.356 0.204 1.65 0.55 0.304 10.92 9.75 0.313 0.100 0.300 0.300 0.260 0.200 0.150 0.060 mm TYP. 3.32 0.020 0.045 0.014 0.008 0.065 0.022 0.012 0.430 0.384 MAX. MIN. inch TYP. 0.131 MAX. 5/7 L9686 SO8 PACKAGE MECHANICAL DATA DIM. A a1 a2 a3 b b1 C c1 D E e e3 F L M S 3.8 0.4 4.8 5.8 1.27 3.81 4.0 1.27 0.6 8 (max.) 0.15 0.016 5.0 6.2 0.65 0.35 0.19 0.25 0.1 mm MIN. TYP. MAX. 1.75 0.25 1.6 0.85 0.48 0.25 0.5 45 (typ.) 0.189 0.228 0.050 0.150 0.157 0.050 0.024 0.197 0.244 0.026 0.014 0.007 0.010 0.004 MIN. inch TYP. MAX. 0.069 0.010 0.063 0.033 0.019 0.010 0.020 6/7 L9686 Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifications mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information previously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of SGS-THOMSON Microelectronics. © 1995 SGS-THOMSON Microelectronics - All Rights Reserved SGS-THOMSON Microelectronics GROUP OF COMPANIES Australia - Brazil - France - Germany - Hong Kong - Italy - Japan - Korea - Malaysia - Malta - Morocco - The Netherlands - Singapore Spain - Sweden - Switzerland - Taiwan - Thaliand - United Kingdom - U.S.A. 7/7