33099

` External High-Side MOSFET Control of a Ground-Referenced Field Winding
` LRC Active During Initial Start
` V<sub>set</sub> at ±0.1 V @ 25
` <0.1 V Variation Over Engine Speeds of 2,000 to 10,000 RPM
` <0.2 V Variation Over 10% to 95% of Maximum Field Current
` Controlled MOSFET and Field Flyback Diode Recovery Characteristics for Minimum RFI
` Trimmed Devices Available at 14.6 V and 14.8 V (typical) V_set

1. 125ns wide square wave pulse.
2. Maximum time = 2 minutes.
3. ESD1 testing is performed in accordance with the Human Body Model (C_ZAP=100 pF, R_ZAP=1500 ).
4. ESD2 testing is performed in accordance with the Machine Model (C_ZAP=200 pF, R_ZAP=0 ).
5. ESD2 voltage capability of PHASE FILTER terminal is greater than 150 V. All other device terminals are as
    indicated.
6. Terminal soldering temperature is for 10 seconds maximum duration. Not designed for immersion 
    soldering. Exceeding these limits maycause malfunction or permanent damage to the device.

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.

The 33099 uses a feedback voltage to establish an alternator field current that is in harmony with system load currents. The output voltage is monitored by an internal voltage divider scheme and compared to an internal voltage ramp referenced to a bandgap voltage. This approach provides precision output voltage control over a wide range of temperature, electrical loads, and engine RPM.