L497 STMicroelectronics, L497 Datasheet
L497
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L497 Summary of contents
Page 1
... The device drives an NPN external darlington to control the coil current providingthe required stored energy with low dissipation. A special feature of the L497 is the programmable time for the recovery of the correct dwell ratio T when the coil peak current fails to reach the nominal value. In this way only one spark may have an energy less than the nominal one during fast acceleration or cold starts ...
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... L497 ABSOLUTE MAXIMUM RATINGS Symbol I D.C. Supply current 3 Transient Supply Current (t V Supply Voltage 3 V RPM Voltage 6 I D.C. Driver Collector Current 16 Pulse ” V Driver Collector Voltage 16 I Auxiliary Zener Current 7 I D.C. Overvoltage Zener Current 15 Pulse ” tr Repetition Time > = 3ms ep V Reverse Battery Voltage if Application Circuit of Fig used ...
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... Connection for the Coil Current Limitation. The current is measured on the sensing resitor R and taken through the divider R S limitation value is given 0.32 I sens L497 and ground by diodes 3 limits pin the delay src is the delay P resistor at pin 12 the T W resistor at pin 12 ...
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... L497 PIN FUNCTIONS (continued) Name N 14 DRIVER EMITTER OUTPUT 15 OVERVOLTAGE LIMIT 16 DRIVER COLLECTOR INPUT ELECTRICAL CHARACTERISTICS (V Symbol Parameter V Min Op. Voltage 3 I Supply Current 3 V Voltage Supply S V Supply Clamping Zener Voltage Input Voltage 5 I Input Current 5 V Darlington Driver Sat. Current 16– ...
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... when the external Darlington is in the active region. sense coil APPLICATION INFORMATION Figure 1 : Main Waveforms. Test Conditions 11C 11D L497 Min. Typ. Max. Unit 0 1.20 1.25 1.30 V 5/11 ...
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... L497 DWELL ANGLE CONTROL The dwell angle control circuit calculates the con- duction time D for the output transistor in relation to the speed of rotation, to the supply voltage and to the characteristics of the coil. On the negative edge of the Hall-effect input signal the capacitorC beginsdischargingwith a constant ...
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... When the in- put signal goes low again C P and the current control loop operates normally. The delay time T is given (sec Where R is the biasing resistor on pin 12 (in K) and 7 Cp the delay capacitor at pin 9 (in F). P L497 is swiftly discharged 7/11 ...
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... Moreover the resistor R overvoltage even when supply voltage is discon- nected during the high voltage condition. current during REVERSE BATTERY PROTECTION Due to the presenceof externalimpedanceat pin 6, 3, 16, 15 L497 is protected against reverse battery voltage. NEGATIVE SPIKE PROTECTION . If correct operation is requested also during short C ...
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... DIP16 PACKAGE MECHANICAL DATA mm DIM. MIN. TYP. a1 0. 2.54 e3 17. MAX. MIN. 0.020 1.65 0.030 0.5 20 8.5 7.1 5.1 3.3 1.27 L497 inch TYP. MAX. 0.065 0.020 0.010 0.787 0.335 0.100 0.700 0.280 0.201 0.130 0.050 9/11 ...
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... L497 SO16 PACKAGE MECHANICAL DATA mm DIM. MIN. TYP 0 0. 9.8 E 5.8 e 1.27 e3 8.89 F 3 10/11 MAX. MIN. 1.75 0.2 0.004 1.6 0.46 0.014 0.25 0.007 0.5 45 (typ.) 10 0.386 6.2 0.228 4.0 0.150 1.27 0.020 0.62 8 (max.) inch TYP. MAX. 0.069 0.008 0.063 0.018 0.010 0.020 0.394 0.244 0.050 0.350 0.157 0.050 ...
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... SGS-THOMSON Microelectronics. 1998 SGS-THOMSON Microelectronics – Printed in Italy – All Rights Reserved SGS-THOMSON Microelectronics GROUP OF COMPANIES Australia - Brazil - Canada - China - France - Germany - Italy - Japan - Korea - Malaysia - Malta - Morocco - The Netherlands - Singapore - Spain - Sweden - Switzerland - Taiwan - Thailand - United Kingdom - U.S.A. L497 11/11 ...