The 33099 is designed to regulate the output voltage in diode-rectified alternator charging systems common to automotive applications. The 33099 provides either an analog or digital fixed frequency duty cycle (ON/OFF ratio) control of an alternator's field current. Load Response Control (LRC) of the alternator field current is accomplished by selecting the duty cycle for prevailing engine conditions to eliminate engine speed hunting and vibrations caused by abrupt torque loading of the engine owing to sudden electrical loads being applied to the system at low engine RPM. Four LRC rates are selectable.