LM1949N/NOPB (TEXAS INSTRUMENTS)

The LM1949N/NOPB is an Injector Drive Controller for use with throttle body injection and fuel injection. The linear integrated circuit serves as an excellent control of fuel injector drive circuitry in modern automotive systems. The IC is designed to control an external power NPN Darlington transistor that drives the high current injector solenoid. The current required to open a solenoid is several times greater than the current necessary to merely hold it open, therefore, the LM1949, by directly sensing the actual solenoid current, initially saturates the driver until the peak injector current is four times that of the idle or holding current (-). This guarantees opening of the injector. The current is then automatically reduced to the sufficient holding level for the duration of the input pulse. In this way, the total power consumed by the system is dramatically reduced.